1.5 Ramanathapuram District and Rameswaram Island ........6 ...... Han.nathaPul'. 19.U. KosMnanga i. 20.Va I anthara.Va I. 21 .Perunal I. 22 .Tirupptllafli. 23.Sikk&1. 24. ...... 340 REM ARRAY E : 1-Ca 2-49 3-aK 4-8CO3 5-0O3 6-Cl. 1350 RFM.
DIGITAL EVALUATION OF GROUNDWATER RESOURCES IN RAMANATHPURAM DISTRICT, TAMIL NADU
THESIS SUBMITTED TO THE MANONMANIAM SUNDARANAR UNIVERSITY FOR THE AWARD OF DEGREE OF DOCTOR OF PHILOSOPHY IN GEOLOGY BY J.F.LAWRENCE DEPARTMENT OF GEOLOGY V.O.C.COLLEGE, TUTICORIN-3
1995
UNDER THE GUIDANCE OF DR.A.BALASUBRAMANIAN UNIVERSITY OF MYSORE
Contents Certificate Declaration Acknowledgements Page No.
Title
Section No.
[ . :ra!l;IIli:i;tSJ] uiI [•j: 1.1 Introduction ........................1 1.2 Scope
...........................2
1.3 Aims and Objectives ....................2 1.4 Resume of previous studies on coastal aquifer in India ........4 1.5 Ramanathapuram District and Rameswaram Island ........6 1.5.1 Geographic setting 1.5.2 Accessibility
..................7
.....................7
1.5.3 Mode of living and Industrial development
.........9
........................
1.5.4 Climate
1.5.5 Land use and agr;ult're
...............10
1.5.6 Physiography ......................10 1.5.7 Surface iater facilities 1.6 Order of preertiofl F
......................
............................
3
CHAPTER 2 GEOLOGY AND SOIL 2.1 Introduction .......................16 2.2 Geology of Tamil Nadu State ................16 2.3 Geology of Ramanathapuram District .............18 .................20
2.3.1 Archaean formation 2.3.2 Tertiary formation
..................20
2.3.3 Recent to sub recent sediments 2.4 Soil and their characterstics 2.4.1 Black cotton soil
................22
..................23
2.4.2 Red ferrugininous soil 2.4.3 Sandy soil
............22
.................23
.....................23
2.5 Subsurface Geology
...................31
2.6 HydrogeomorpholOgy ...................34 2.6.1 Topography ....................36 2.6.2 Drainage network ..................36 2.6.3 Geomorphic features .................37 2.7 Lineament Tectonics
...................37
2.8 Hydrogeologic significance .................39
CHAPTER 3 HYDROMETEOROLOGY 3.1 Introduction .......................41 3.2 Weather cycle .......................43 3.3 Rainfall and Run off
.....................43 47
47
3.5 Evapotranspiration
.................48
3.6 Infiltration capacity of soil
3.7 Other meteorological factors ................49 3.7.1 Relative Humidity ..................49 3.7.2 Soil moisture content .................49 3.7.3 Wind Velocity ....................49 3.7.4 Impact of meteorological factors on hydrology .......50
CHAPTER 4 HYDROGEOLOGY 4.1 Introduction ........................51 4.2 The Nature of aquifer ...................51 4.2.1 Crystalline terrain
..................52
4.2.2 Sedimentary terrain 4.3 Groundwater flow
.................54
....................55
4.3.1 Hydraulic properties of porous media 4.4 Saline intrusion in coastal aquifer 4.4.1 Coastal hydrogeology
..........55
...............57
................57
4.4.2 Basic principle ...................58 4.4.3 Salt water sources ..................63 4.4.4 Mechanism of intrusion ................63 4.4.5 Numerical approximation ...............64 4.4.6 Analysis of salt water upconing .............66 4.5 Water levels
......................66
• 69
4.5.1 Depth to water table in wells 4.5.2 Water level fluctuation
................70
4.5.3 Grid deviation water table ...............74 4.6 Aquifer Parameter Evaluation ................77 4.6.1 Field test
.....................77
4.6.2 Data processing
..................81
4.6.3 Specific capacity analysis ...............94 4.6.4 Time for full recovery analysis 4.7 Potentiality of aquifer 4.7.1 Transmissivity
.............99
...................102 ...................102
4.7.2 Optimum yield - out put ................106 4.7.3 Time for full recovery in wells
.............108
4.8 Computing the length of saline intrusion 4.9 Well design
...........108
........................110
CHAPTER 5 HYDROGEOCHEMISTRY 5.1 Introduction ..............
112
5.2 Chemical character of water
113
5.3 Observation network
117
5.4 Sampling and analysis
117
5.5 Method of presentation of data
117
5.6 Method of Interpretation .........
118
5.6.1 Hydrochemical parameter evaluation by computer technique .......
118
.
5.6.2 Electrical conductance
125
125
5.6.3 Interrelationship of ions ...........
5.6.4 Groundwater hardness, salinity and sodium hazard
140
143
5.6.5 Groundwater type ............. 5.6.6 Corrossivity ratio
143
5.6.7 Calcium carbonation saturation index
145
146
5.6.8 Index of base exchange
148
5.7 Mechacism Controlling Groundwater Chemistry 5.7.1 Gibb's plot ................
148
148
5.7.2 Reconstructed Diamond field
150
5.7.3 Hydrochemical facies 5.7.4 Stuyfzand classification ...........
152
156
5.8 Extend of saline intrusion
156
156
159
5.9 Geochemical modelling ............. 5.9.1 Factor analysis
..............
5.9.2 Pictogram correlation matrix ......... 5.9.3 Dendrogram
................
161
CHAPTER 6 GROUNDWATER GEOPHYSICS 6.1 Importance
.............
6.2 Electrical Resistivity method 6.2.1 General principles ........ 6.2.2 Formation resistivity ....... 6.3 GeoelectriCal survey
162 162 • 164 164 168
168
6.3.1 Profiling 6.3.2 Vertical Electrical Sounding
..............168
6.3.3 Electrode configuration .................168 6.3.4 Geoelectric parameters ................169 6.3.5 Data processing
..................171
6.3.6 Interpretation technique ................171 6.4 Instrumentation and observation
...................188
6.5 Geoelectrical models 6.5.1 Isoresistivity
..............188
....................188
6.5.2 Iso apparent resistivity
................191
6.5.3 Transverse resistance
................194
6.5.4 Specific conductance
................194
6.5.5 Aquifer anisotropy ..................194 6.6 Hydrogic significance ...................194 6.7 Well logging
......................195
CHAPTER 7 SIMULATION OF SALTWATER INTRUSION 7.1 Groundwater model
...................202
7.2 An overview of saline intrusion models ............204 7.3 Sharp interface models
...................205
7.3.1 Two fluid approaches 7.3.2 Salt water only
................205
...................206
7.4 Dispersed interface models
................207
7.4.1 Non density dependent models .............207
208
7.4.2 Density dependent models
• 209
7.5 Aquifer simulation program applied
230
7.6 Results of simulations ......
• 230
7.6.1 Ramanathapuram District
7 I .'J.. I #)
I
IVVI
III
241
IcInd I'.
CHAPTER 8 GROUNDWATER MANAGEMENT 8.1 Importance
• 245
...................
247
8.2 Utility of groundwater modelling in management .
• 248
8.3 Management options ................
CHAPTER 9 SUMMARY AND CONCLUSIONS . . . . . .
250
APPENDIXES A-APE .....................
• • . . 254
....................
• . • . 257
B- HYCH
• 262
C - SUTRA (Preprocessor) D - Ramanathapuram District (Ramnad Data Input file details)
• . . . 268
E - Rameswaram Island (Data Input file details) .....
• . . . 269
F - Co-ordinates of locations referred in the text .....
270
REFERENCES
. . . . . . . . . . . . . . . . . . .
271
CHAPTER I
INTRODUCTION 1.1 INTRODUCTION A large part of the world's exploitable water resources is abstracted as groundwater. Groundwater is treated by the public as a common pool resource. In coastal areas, because of the increasing number of settlements and population, the control or management of available water resources becomes difficult and needs a detailed analysis. The limited availability of potable water resources due to the high salinities generated by the adjacent sea water enhances the need for an immediate action along the coastal aquifers of Rarnanathapuram District, Tamil Nadu. These resources may experience disastrous and almost irreversible impact if improperly managed. The use of coastal aquifers as operational reservoirs in water resources systems also requires the deveopment of efficient tools that make it possible to predict the behaviour of aquifer under different conditions. The Earth Summit met at Rio de Janiero, Brazl considered the recommendations of the ICWE (International Conference on Water and the Environment), held at Dublin in January, 1992, and stressed that it is essential to protect the coastal groundwater resources against over-exploitation, adverse changes in hydrological systems resulting from human activities and pollution, many forms of which can produce irreversible damage. ICWE strongly recommended the need
4
2 for prevention of saline intrusion into the aquifer through careful management of abstraction rates, and wherever appropriate, artificial recharge. In India, it has been found to be a matter of great concern to solve the coastal aquifer problems in Gujarat, Tamil Nadu, Karnataka, Kerala, Andhra Pradesh and a few other states. The importance of protecting, these aquifers against such problems has led to many rigorous investigations.
1.2 SCOPE Salt water encroachment is the major hazard to the public in all coastal zones. The intrusion often results firstly in the loss of potable water resource and secondly in the need to develop costly remedial measures. For efficient planning and management of coastal aquifers, it is also essential to predict the extent of intrusion into the aquifer in response to variation in the component of freshwater flow and recharge. This requires an
(i) understanding of the existing groundwater conditions, (ii) the factors which determine the intrusion and (iii) appropriate methods of estimating the extent of encroachment and its seasonal fluctuations. Better water management practices to limit the intrusion and to tap the fresh groundwater resources could be proposed only through tntegrated hydrogeological study carried out with digital modelling techniques.
1.3 AIMS AND OBJECTIVES It is aimed to analyse the role played by the geology and structural characteristics of various lithological units, physiographic features. hydrometeorological
ti
4
a -cLA LL
4
0
>
cu
'I-)
a
Cl CL
E a
a
76 el
I-
ftcu L)
a a I-
ci. •
C
4 _J
a.
LL LL
iW '-4
L
oz
S
a z
(i-i
W
a
>-
If)
Ln
Oa 4
(.D
L)2 tnw
U (fl
E ,
•O _
Ql
4A v_I . — — In U
E I1
V_I
u
_Ina
a
Eo
3:
0E
E
a
•5 cr
::L cr L a
D ., •
L)
— C Sp— co
Z
CA ti:
elements and aquifer properties on, the occurrence, availability and quality of groundwater resources of Ramanathapuram District including the Rameswaram Island, Tamil Nadu. It is also planned to delineate the aquifer boundaries, potential zones and saline pockets using geophysical techniques and hydrochemical studies. The following are the main objectives of the present study: (1) To evaluate the groundwater resources of Ramanathapuram District through an integrated hydrogeological approach using numerical techniques, (2) To develop a computer model of the aquifer useful for predictive simulations, and (3) To propose possible groundwater management strategies to protect the aquifer environment from salinity intrusions.
1.4 RESUME OF PREVIOUS STUDIES ON COASTALAQUIFER IN II I'] Coastal hydrogeological condition can be represented as 1. an unconfined aquifer, 2. confined single layered aquifer, and 3. a multilayered aquifer sequence (Fig. 1.1). Depending upon the nature of the geological formations, hydrologic conditions and the anthropogenic influence, the position. and shape of the interface gets modified regularly. Quite a lot of works have been made on these aquifers in several countries. India has a long stretch of coastal zone extending over 6000 km. In the recent past proper attention has been paid regarding the saline intrusion along
the coasts. Mangroal-Chorwad Coastal hydrogeoiogy of Saurashtra, Gujarat has been studied by Desai at. al., (1979). Malapuram coastal aquifer studies have been conducted by Chandrasekaran and Ushakumari (1982). A detailed study about the hydrogeology of Tambraparni basin and its adjacent coastal area have been studied by Balasubramanian at.
al.,
(1985). A district level groundwater
evaluation of Ramanathapuram has been carried out by Varadaraj
et. al.,
(1986).
The hydrogeochemistry of Karaikudi-Tiruvadanai coastal zones have been studied by Sastri and Lawrence (1988). Kanyakumari District hydrogeological studies have been done by Sankar
et.
al., (1993). Salinity studies about the coas-
tal aquifers of Karaikal and Thanjavur area of Cauvery Delta have been carriec out by Sukhija at. al. (1994). Integrated approach for the evaluation of coastai aquifers of Tiruchendur area, Southern Tamil Nadu has been done by Subramanian and Balasubramanian (1994). Potential zones for groundwater development in Tambraparni river basin and adjacent coastal area has drawn the attention of Sanif at. al., (1994). The outcome of these studies have illustrated the avaability of various methods for groundwater evaluation. A detailed integrated groundwater investigation incorporating the computer techniques was lacking and hence an attempt has been made to analyse the hydrogeology of Ramanatnapuram District including the Rameswaram Island.
1.5 RAMANATHAPURAM DISTRICT AND RAMESWARAM ISLAND
Ramanathapuram District occupies the southeastern part of Tamil Nadu (Fig. 1.2). Rameswaram is known for its cultural heritage and srcnitectural creations. According to legend, 'Lingamin Rameswaram temple was established in a
thatched shed by Seetha and called "Rama Linga. Later the temple was built over a period of more than 500 years. The age of the temple cannot be determined exactly. Till independence, Ramanathapuram Kingdom (Samasthanam) was ruled by Sethupathy family. 1.5.1 Geographic setting Ramanathapuram District occupies the southeastern part of Peninsular India. Viith an areal extent of 4207 sq.km ., the District lies between the latitudes 95'OO and 9° N and longitude 78° 13'00" and 79' 2600' E, forming part of the Sn.:ev of Inca Topo sheets 58/K and 58/0. For administrative purposes, this District as been divided into six taluks and eleven blocks. Rameswaram island forms a :a of Rarnanathapuram district. This district is bordered by the Palk bay in the east. Gulf of Manaar in the south, Pasumpon Thevar, Kamarajar and Chidarrcaranar istricts in the north. west and southwest respectively. The Ramesvaram island is separated by the Palk strait. 1.5.2 Accessibility Eamanathacuram is connected by a metre gauge line of Indian Railways and located in The Manamadurai-RameSWaram tine. It is also linked with Tiruchiraoa:ii-MacaS line. The area is accessible by the National Highway NH-49 from Maourai. (the temple city of Tamil Nadu) existing 110 km in the western side. This dis:ric: is also approachable from Devakottai, the native town of the author, by State Hghwas. F.ameswaram Island is connected to the mainland by railways through Pamban brdge which can be lifted for navigational purposes and by road it is 50 km scutneast of Ramanathapuram.
it-
ULI
-
-
-
-. -
--.
-
-:----. -i- :- -
,.r
-
-
-
- -• - .-
.
- .--
- -
- - • -.- -
- -
-:.--__- -.-
- •_-.;
• -
---- .---
--
-
-- - --
-
-
._ - -.
-
-
-
2-
—
---- •:.__-_._-.---__ -
-.----•; -
-
-
__-
. --
-. --
--
RIP-
-
- ,glop.-.
Z.
-- *
- ..- -
•, .
Pt. NO. 1. SALT - PAN AT VALJNOKKAM.
-AM •-
$lls!;.
--
____;-=---
---.-----.- -
--
.
-
-
. -7 --...-,'I..
..
-..-.
...
PI.N O2PANORAMIC VIEW OF R.S. MANGALAM TANK (PRE MONSOON)
I-J N)
9 1.5.3 Mode of living and industrial development
The district has a very few industries. Till recently it has been declared as an industrially backward district. A few small scale industries and agro-based industries are located near Paramakudi and Kamudi. As far as mineral wealth is concerned it is very poor. The available coral reefs are exploited by the chemical industries for manufacturing calcium carbide. A small pilot plant of a magnesium production unit, is located near Valinokkam with the technical know-how of the Central Electrochemical Research Institute, Karaikudi. Even salt industries are not well developed, however the Salt Corporation, Tamil Nadu is having a few salt pans at Valinokkam (Plate 1) and is planning to have some more at Mariyur. A few prawn culture and processing plants are located near Mandapam. It is also expected that more number of intensive marine aquafarms are likely to come up along the coastline of the district. Recently it has been established that a good amount of cement grade shell limestone of subrecent age is also available.
1.5.4 Climate
Generally this area experiences a tropical climate with a maximum temperature of 39 C C (between the period of March and May). The annual average temperature varies between 25.9 C and 30.6 C with an average humidity of 65%. Cyclonic storm is a regular phenomenon all along this coast. The normal wind speed is about 5 to 10 kmph and sometimes it exceeds over 100 kmph too.
With reference to precipitation, the District enjoys three distinct patterns. The first part of the year, from January to May forms a non-monsoon period. Occasionally a small amount of rainfall is recorded. The second part, from June
to September, gets a moderate rainfall and forms the southwestern monsoon. In the end, October to December, this area receives a heavy rainfall and forms the North-eastern monsoon. The annual average rainfall of this District is 872.9 mm.
1.5.5 Land use and agriculture
The District has 4.488 hectares of land covered under forest. In the rest of the portion, nearly 7,417 hectares of land is under cultivation and remaining 7,964 hectares form a barren uncultivable land. The main reasons for non-cultivation are the non-availability of water. poor quality of groundwater and poor fertility of soil. In spite of this condition, agriculture is the main source of living. Tank and well irrigation methods are practised. Tube well and dug well irrigation is practised in around 281 hectares. Rain fed and river fed tanks are evenly distributed in all the taluks of the District, except the Rameswaram Taluk. Tube wells are restricted only to Kamudi. Mudukulathur. Paramakudi and RamanathapUram taluks. Large diameter dug wells are the special features of Ramanathapuram.
As already stated the non-availability of good quality water and poor fertility of soil restrict the choice of farmers. Near rainfed tanks, paddy is cultivated as one time crop. During dry season, maize (Cholam) and ragi are cultivated. In some areas, cotton and groundnuts are grown.
1.5.6 Physiography
Physiographically the district can be classified as,
1) a vast black cotton soil plain (f Paramakudi. MudukulathUr RamanathapUram and Tiruvadanai taluks),
1: 2) a western upland with in an elevation of 9 to 20 m amsi. 3) a sandy coastal plain of Mudukulathur, Ramanathapuram, Rameswaram and Tiruvadanai Taluks and the 4) north central plain having red soil. Southern coast of the District is flanked by a chain of islets. Niumerous sand dunes extend up to 3 to 4 km interior from the coastline Geomorphologically, this area has the following landforms, namely aeolian, marine and fluvial landforms. A major belt of sand dune is seen between Nayakulam and Adamcherri extending for about 10 km up toSayalkudi. The heights of the dunes vary from 4 to 5 m. Transverse. Longitudinal, crescent shaped and fixed types of dunes occur in this area. A number of marine and fluvio marine landfcrms are observed in the area. Mud flats near Pallamorkulam and tidal flats near Ervadi are notable features. Estuary, barrier bars and ridges are also observed near Servarumai and Ervadi, respectively. Two lagoons are located in the south eastern part of the district. Fluvial features like river terrace, palaeochannel, flood basin, Natural levee and point bar occur in many places. River terrace is seen near Mudalur and south of Pullangudi. Palaeochannels are traced from satellite imagery near the course of Gundar river and Gundar channel, which are of hydrogeolgical interest. Backswamp deposits are noticed near Kavanur, west of Pullangudi, east of Mucialur and along the west of Kulathur.
A. --
=
1.
.,. ••-..I.
- •
- •-
---.
-
-- ---.
•'
u'
- ••
PI.NO.2.PANORAMC VIEW OF P.S .MANGALAM TANK (PRE MONSOON)
.-
1.5.7 Surface water facilities The district has nearly 1731 rainfed tanks, and many of them remain dry for a major part of the year. The major river, Vaigai, drains through this District. Gundar river and Gundar channel enter in Kamudi Taluk and flow through Mudukulathur. There are two major tanks available for surface water storage, viz. R.S. Mangalam tank (Plate 2) and Ramanathapuram tank and these tanks are utilized for irrigation. Due to poor maintenance of these rainfed tanks, much of the collected rain water is lost by surface run off.
1.6 ORDER OF PRESENTATION The entire work done through an integrated approach is presented in the form of 9 chapters. Chapter 1 deals with the general aspects of the study and the area, comprising (1) the scope and objectives of the present work; (2) a brief resume of earlier studies made in India; (3) general description of Ramanathapuram and Rameswaram Island and (4) an outline of the various aspects covered in this work. Chapter 2 deals with the geomorphological features including, physiography, drainage, topography, hydrogeomorphic units, general geology and subsurface lithology and structural features.
In Chapter 3, the role played by the hydrometeorological elements including rainfall, climate, evaporation, evapotranspiration and humidity, have been assessed for determining the quantity of groundwater recharge. Chapter 4 covers the hydrogeology and the important aspects considered are the (1) general description of groundwater conditions, the behaviour of the aquifer media using watertable maps and water level fluctuation records, (2) pattern of groundwater flow, (3) delineation of the zone of recharge and discharge using a grid deviation water table, and (4) aquifer parameter evaluation, and discussion of the aquifer characteristics. Chapter 5 discusses the geochemistry of groundwater with the following aspects:(1) Based on the major ions, the groundwater hardness, water typesc corrosiveness have been classified. (2) The suitability of groundwater for domestic, agricultural and industrial purposes has been assessed. (3) The geochemical model of the groundwater system has been developed based on multivariate statistical analysis.
1
In Chapter 6, the geoelectric characteristics of the aquifer system have been discussed. Based on the vertical electrical soundings, conducted during this study,the groundwater potential zones have been identified, and the disposition of saline-fresh water horizons have been demarcated. Chapter 7 is devoted to the numerical simulation of saltwater intrusion. Chapter 8 includes a discussion on the groundwater management strategies to be adopted in this area. In Chapter 9, a summary of the work carried out and conclusions derived based on the findings, related to various aspects are presented. Appendices A to F give the computer programs data bases used for process and the coordinates of hamlets referred in the text.
LLJ
U)
cr
I
' E
2
61
j_jL7
LLJ
•, i
•
I
'Th
T7H
I.:3'l
cx
b •
Uj
(I
i: cx
i\j \
cl
4/
Ln
UI
17
18 Table 2.1 Areal distribution of geological formations in Tamil Nadu. S.No. Description 1
2.
Area in sq.km .
Sedimentaries (a) Quaternary formations (b) Tertiary (including laterite) (c) Cretaceous (d) Gondwana Archaean complex Total
22,018 8,546 1,515 2,523 95.467 1,300,069
The Archaean group includes gneisses of complex nature, khondalite and charnockite, which are intruded by ultrabasics, granite and syenite. Clay, sand and limestone belonging to the Cretaceous of Tiruchinopoly are found to overlie the upper Gondwana. Their age is considered to be as MioPliocene.The coastal plains and the deitaic regions of Gulf of Manaar are filled with recent to subrecent alluvium and corailine limestone.
2.3 GEOLOGY OF RAMANATHAPU RAM DISTRICT Ramanathapuram district has a simple geological configuration (Fig. 2.1). The western boundary of the district (i.e. west of Kamudi ) has mostly crystalline basement with a thin sedimentary cover. They are mostly of biotite gneiss, granites and basic intrusions. The other parts, including the coastal plain, are mostly covered with the recent to sub recent alluvium. Older sedimentaries are met only at deeper horizons. From the bore hole litholog records of the Oil and Natural Gas Commission (O.N.G.C.), India it is inferred that along the sedimentary tract, the crystal-
Table 2.2 Stratigraphic succession of formations in Ramanathapuram District, Tamil Nadu. Period
Age
Stage
Morphostratigraphic Unit
Lithology
.__ Quaternary
Pleistocene Ervadi formation
Beach deposits barrier Sand dune deposits
Sand
to Recent
Devipatinam
Tidal flats, estuary,
Clay
formation
lagoonal strand plain
Fine to
deposits
medium sand
Holocene Pallamorkulam Mud flat deposits
Clay
formation to Late Pleistocene Holocene Pullangudi
Mud flat deposits
Clay
formation Holocene Vaigai-Gundar Channel bar and bed load formation
Sand, silt
deposits
and clay
Point bar deposits
Silt and sand
Levee deposits
Silt and sand
Cuddalore
Backswamp deposits terrace deposits
Clay
Floodplain deposits
Sand. silt and clay
Palaeochannel deposits
Sand and Silt
Fluvial deposits
Sandstone, clay and gravel
Tertiary
Miocene
Archaean
-------------------------Unconformity Precambrian
Silt
Biotite gneisses granite and associati Basic intrusives (After Varadara) and Parthasarathy, 1986)
r
tines are encountered at a depth of slightly greater than 3500 m near the southeastern part of Ramanathapuram, at a depth of 1640 m near Mandapam and in a few other places at a depth of about 2000 m. The general geological succession is given in Table 2.2.
2.3.1 Archaean formation The Archaean rocks, mostly gneisses, (including biotite and hornblende gneisses) are exposed over the northwestern part of the Ramanathapuram District near Kamudi. The regional trend of the gneiss is NNW-SSW with varying dips. The crystalline rocks occur at a shallow depth in the western boundary of the district. In the central parts, it occurs at a greater depth. The depth to the basement at Paramakudi is about 300 m (bmsl). Towards Ramanathapuram the depth to the basement gradually increases. It has been observed at the Rameswaram Island, that the basement is met at a depth greater than 2,000 m.
Near Kamudi, a small patch of quartzite is exposed in the form of a ridge, which is also dissected by many sets of master joints.
2.3.2 Tertiary formation The Tertiary formation occurs as consolidated sedimentary rocks and exposed between Kamudi and Abiramam. These overlie the crystalline Archaean complex with a marked unconformity. They are commonly known as Cuddalore sandstones. The thickness of the sediments, varies from a few metres to about 15 m as disclosed by the well sections. Generally this sandstone is friable and
Table 2.3 Lithostratigraphy of Mandapam, Ramanathapuram District
Era
Cenozoic
Period
Epoch
Quaternary Recent
Depth range m
0-105
Lithology Loose sand, light grey to whitish grey, fine to coarse grained, hard compact, calc. sandstone, arenaceous limestone
Neogene
Pleistocene 105-386
Grey to greenish grey, mod hard and compact, fine to coarse grained, often cong. sst with a few bands of light grey silt stone and light yellow, feebly caic. sandstone
Miocene
386-576
Alternatively thick bands of grey to greenish grey, fine to to coarse grained, hard compact calc. sandston and light brown granular fossiliferous sandstone with a thin band of greenis grey calcareous claystone
576-680
Alternations of greenish grey to grey fine to coarse grained mod compact sandstone grey to light yellow arenaceous clay stone with a few bands of grey siltstone
UNCONFORMITY_______________________________________ Palaeogene Oligocene 680-944
Grey hard compact fossiliferous granular sandstone
Upper
944-1644
Greenish grey slightly silty Caic. sandstone, shale with few thin
Eocene
band of grey siltstone
Middle Eocene Upper Palaeocene
UNCONFORMITY_____________________________________
Azoic
Archaean
1644
Granite gneiss
highly weathered
Occasionally, laterite capping is also seen above these
Tertiary formations. Mottled and friable sandstones are associated with stiff clay. Gravel beds are seen along the contact zones between the crystalline rocks and sedimentary beds.
2.3.3 Recent to sub recent sediments Most of the part of the District is covered by an alluvium of recent origin. It comprises clay, silt and sand. It has been observed that the sedimentation has taken place under fluvial, fluvio-marine, marine and aeolian environments.
The detailed stratigraphic succession obtained from the borehole drilled by the ONGC, India, at Mandapam is given as Table 2.3.
2.4 SOIL AND THEIR CHARACTERISTICS The physico-chemical characteristics of surface soils in any hydrogeologic system, play a significant role in controlling the recharge potential of an aquifer and--in turn the runoff volumes. The cohesive and non-cohesive types of soils have a major bearing over the infiltration rate.
The soils of this district are classified as black, red-ferruginous and arenaceous or sandy soil.
2.4.1 Black cotton soil The black cotton soil is confined to Paramakudi and Ramanathapuram area. It is clayey, highly porous, magnesia rich, plastic and mostly saturated with Ca and Mg. The soil gets swelled after water saturation and becomes sticky. They form polygonal sun cracks after dryness. Formation of sun crack is a characteristic feature of this soil in many parts.
2.4.2 Red .1errugifloUS soil Red soil occurs as patches in many parts of the District. The south western zone adjoining Paramakudi and Abiramam are characterised by red soil. This soil is rich in iron. Between Sayalkudi and Valinokkam a few patches of red soil are seen and are mostly garnetiferouS. Locally, these red patches are known as Teri sands. The thickness of these Teri sands, is limited to a few metres only.
2.4.3 Sandy soil River courses and coastal plains are characterised by the sandy soil (arenaceous). The loose sandy soils blown by the wind slowly migrate and pose problems for cultivation as well as for the Railway traffic. In certain months of every year, sand dunes cover the railway tracks, which require periodical monitoring and maintenance. Black cotton soil is suitable for the cultivation of maize, chillies and cotton. Paddy cultivation is practised in certain clay soil horizons wherever irrigation by tanks are possible. Ferruginous soils and laterite cover are quite unsuitable for cultivation. The poor quality of groundwater and the infertility of soil have restricted the crop patterns and their areal extent.
24 78130'
7910'
Fig. 2.2 RAMANATHAPURAM DISTRICT AQUIFER BASEMENT
Pudukottai Ut
/ - -
PM.T Ut.
,. -100
Kamarajar
Ot.
/
30 1
,/
/
-' / o
N
/ /
I
I
/ /
'
PaLk bay
INDEX 1 Basement contour (in m I bmsl) j
c?
V
0
0
0
/
I
/
I
I
/
Gulf of manuar /
I
0 5 10KM
/
Chidambaru -nar DI
Fig. 2.3
Pudukottoi of
RAM A NATH A PU RAM DISTRICT. LITHOLOGIC SECTIONS
KA'ATHAKUUI
F
TI
I
136 ALAPURAM
E
13A
MANDANARKOIL
B p0
VETRIYUR
F'
P.M.T 0 Kainarajar Of.
E1
PIV
lcD
A'
JJNAKULAM/
Palk bay
pj 11 pti 'I I
BI
-
0 Gulf of manaar
Al
¶3\
Q 5 10KM
[hid am baru - par Ut 78130
N
79O
INDEX I A-A' Reference 1to Section
z
0 I— 'I)' - z .2w
S
- - -
I
l i
I
i 11
w
-
!PflI0ADS(i
.7
WDfl5UDIIAO opUUDuJWDd
wDJnd:1:p:J:A ppuiDlInd
wOlflOUOd 1-•'.'
CL
I
r1l
I—
) I
-
>.
0 tr,
00
I
ci J)
0a IJ-
Ii
c'
()
xx
0
Ifl
WOL
C
c
25
z 0
U Ui
(J)7
LLJ
rccxJU!D6o JrlLflDA!Dpj
•
•
I0AUO
-
npouDpn •
-•
-
rI
x
- z
Hi
c
L)
.2
- > i-
•
c u
_-i
®IY 1H' !(\ /II
I.:iIhIHlHlIHK\ I
0
1
I
I
III•
ol
0
:o
;0
0
oI°
00
II
Jll Ilno
Il
II
10
0
PI 0
0 •
D Ln
U')
g
U
I,!)
'if •S
-
S
/:
{!
'fl
.E2
I
::/'
U Li.
I'
-
•'j•'•
WOL
ILL
j
•d
2 'DC3 0
J
U-
26
- DAiJd
woln6Uolod
A
Jj
II
I l l ' Ii
I 1H1.
'I I
I LIhi1 Iii .1I
z
C
I
o
If)
'A
c 0 0 •tc
,4
ci
>-.
ci I-) LI)
C ci
I,
ci -
>, U
0/''I
U
ci
ci
-B
1D1
III
HI
I I 'fi
1
tI
I I
Ii
11111
01
I
I
0 0I 4l00 Ii,
414 0 0 II 11b0
41
j
I
11111
itt
(lIlt -• 4j I0 it'.jIi 0 0 • 00 I4 I I i I I 14 I otII I Hi .Iii1 0 114i 001111111111 •, ''II 1I04it I II '41I I'll HIt i 00 illt I II I .41 0 0 0 0Ii 41 0 ' 0 I I I I I I I I I I I
.HIIi tI •: l\iIi.'I i
-1 4
1 y/:./ i /o°o WUpdold'J,11, /( 0 0/ 1 J I lilt l/I ° o , t/ I I I Jo Q / iI i / I j I J.:v : 1' ' :. 1/ 70° 0/i A 1v1111 44f / II 'R ;- i /00 r I I Iii' / I. I4I /0 ° 1 / -/ I I I /1 4 II I H • I 'I Ii l 14 ' I/Ill I' I
UDIfl)j
/1 hc
LL a-i 0 Lu 0
28
CN
><
II
3
l!0)1J0P0V
ujojrdoodo'j
0
o9 LZ ILl
ull
H
Ln
= 0 0
ci
I _
-
•:
•
o o
/"I l I I'looI''
I
Al I
: 1 111 I
•
Ici C
'
0
0
C
ci
Ln
-
1°
0
00
0
0 0 0
-.
0 0 0
0
C ci
•.
^ Ul
I
I
.
•Ii/'
XV '
óO/t/
.: • f' •
0
0 0
29
J JflIIJAflJIj
P1)1tXIIOAD1
z 0
b L1J LL
LL
o-J
Ui a z
- • 5 a- 0 I—
C 0 C a 'I) a LI
C cu a tJ)
2
Li
a
IJi
I-.
a
>-
2
I1 C
a
LI W
oil
>. a
Co' a, CC
7M
30
3 2.5 SUBSURFACE GEOLOGY In this study, the subsurface geology has been deduced from the litholog details of many exploratory boreholes drilled by various organisations involved in groundwater investigation. With the available subsurface data, the depth to the basement country rocks have been deciphered (Fig. 2.2). Six subsurface sections (Fig. 2.3), nearly perpendicular to the coastline, have been constructed, and shown as Figures 2.4a - f From the depth to the basement contours map and the subsurface geologic sections. the following conclusions have been derived; (1) the thickness of the sedimentary formation increases towards the coast, (2)there is a basement raise near Mandapam, (3) basement uplift and down warping might have given rise to some structural features which might have formed due to post depositional tectonic activities, (4)the basement country rock, at depth, seems to be weathered. and (5) the entire coastal zone is characterised by a very thick pile of sediments.
32 Section along A-A' This geologic section (Fig. 2.4a) incorporates the lithofogy of the bore holes drilled at Pottakulam, Pullandai, Varadarajapuram, Pammanendal, Kovilangulam and Sayalkudi. The total depth of the boreholes along the section varies from 50 m (bgl) (Pottakulam) to 11Q m (bgl) (Kovilangulam). The northern part of the section has sand and clay with a thin cap of laterite. Basement depth varies spatially. Hydrogeologically the sandstone which occurs just above the basement forms the aquifer horizon. Section along B-B' The section denoted as B-B' includes the boreholes at ldaiyathur, Vagainendal, Mudal Nadu, Pookulam and Orivayal (Fig. 2.4b). The depth varies from 25m (bgl) at Idaiyathur and 245m (bgl) at Pookulam. Alternate layering of sandstone and clay favours the development of a set of confined aquifers. A basement fault (?) is suspected between Mudainadu and Pookulam. A thick bed of kankar admixed with sand occurs at a shallow depth. A thin band of quartzite occurs around ldaiyathur. Section along C-C' This section runs along Ariyanendal. Palangulam and Periya ayyakudi (Fig. 2.40). The depth of bore holes varies from 400 m (bgl) at Ariyanendal to more than 750 m (bgl) at Periya ayakudi . Stratigraphicaily this section encompasses lenses of clay, sandstone and limestone. The basement has a suspected thrust between Palangulam and Periya ayakudii. Confined aquifer condition exists at a depth of 400 m (bgl) in and around Ariyanendal. Near Periya ayakudi more than two confined aquifer sequences are noted at a depth of 500 m and further below..
I FIG. 2.5 RAMANATHAPURAM DISTRICTj PHYSIOGRAPHY
WIDO
PUDUKOTIAI
I]
C
'VIRSULI RIVER
PO7
-2 :
LEGEND
cz
RIVER
TANK CONTOUR
KC".TAKARAIYAR RIVER
LEVEL IN FEET
[1 (
-
1
UWAR RIVER
1
1- p k PAIR BAY \ : RAANATHAUI1
or MAflAATI
00
1
33
7f 30
ly
P141 Ot
CHIDAMBAHANM DI.
Section along D-D' This section exhibits a generallised section along Tinaikulam and Periyapatnam (Fig. 2.4d) It gives more information for regional correlation of lateral and vertical variation of the various litho units. This section reveals that lithology in the area consists of mainly clay mixed with kankar.
Section along E-E' This section connects the geology of Gopalapuram and Maudnai Koil (Fig. 2 .4e). The depth of the bore hole ranges around 70 m bgl. Clay, sand admixed with kankar and sandstone form the aquifer media of this section.
Section along F-F' The section F-F' (Fig. 2.4f) incorporates the lithology of Kavathakudi and Tiruvetriyur. The total depth of the bore holes along this section varies between 140 m at Kavathakudi and 70 m at Thuvetriyur. Clay and sandstone of various grain sizes with kankar occur along this zone.
2.6 HYDROGEOMORPHOLOGY
Figure 2.5 shows the physiographiC conditions of the area. Hydrogeomorphic conditions of an area have a bearing over the recharge sources.
3
PI. NO. 3.! RS -1 B VIEW OF SOUTHERN TAMIL NADU.
2.6.1 Topography
Topographically the study area is a flat terrain. Three topographic sections have been derived to bring out the gradients along the coast. The area can be divided into (i) a western coastal upland with an elevation ranging from 40 m to 50 m (ii) a central deltaic plain with an elevation ranging from 5 m to 8 m and (iii) the gently sloping coastal plain near the sea.
2.6.2 Drainage network
The major rivers flowing through the study area are Vaigai, Gundar, Kottakoraiyar. Virusuli and their tributaries. Vaigai river enters near Paramakudi and flows in an east-west direction and drains into the Ramanathapuram tank. For some distance it flows parallel to the coast and turns back to join the sea showing a typical yazoo pattern. It is observed from the satellite imageries that the Vaigai river seems to be structurally controlled by the disposition of basement lineaments. Gundar river drains through the western part of the study area and divides into two distributaries (Plate 3). One of them flows down south and confluences with the sea near Mukaiyear and the other drains into a tank. The streams, Kottakoralyar and Virusuli flow from west to east confluencing with the Palk Bay. Almost all the rivers are dry for most period of the year and they carry flash floods during heavy monsoons. This district has an unique feature in the entire State of Tamil Nadu in having a large number of ranfed tanks out of which Rajasingamangalam and Ramanathapuram tanks are the largest.
2.6.3 Geomorphic features
The study area comprises of fluvial, marine and aeolian geomorphic features.
Channel bars, point bars and natural levees are present along the river courses. Mud flats near Pallamorkulam along Vaigai river indicate a fluvio-marine environment.
The southeastern coastal zone of the district has a wave cut erosional platform. Tidal flats are present between Devipatinam and Kothakudi along the east coast. Barrier ridges and lagoons, mostly indicative of marine origin are found near the southeastern portion of the study area.
Sand dunes are observed from Sayalkudi to Mandapam along the southern coast. The height of sand dunes vary from 3 to 5m and occasionally it exceeds this range. Generally they are transverse, longitudinal and crescent shaped. Some of them are migratory in nature. The thorny bushes, grass, and coconut plantations control the movement of these sand dunes.
2.7 LINEAMENT TECTONICS In any hydrogeological investigation the study of lineament density holds a key role, especially when the lineaments facilitate the groundwater movement. Lineament mapping from satellite imagery provides quite a lot of information. In a sedimentary terrain interpretation of satellite imageries supply details regarding the neotectonic events.
38
39
Major and minor lineaments of this district have been deduced from IRS imagery (Fig. 2.6). Nearly six major lineaments are observed. The rivers, Vaigai and Gundar are confined to major lineaments. A major lineament exists almost parallel to the east coast, which is referred to as Rajamatam - Devipatnam fault (Ramachandran, 1991). Ramanathapuram district has been dissected by a number of minor lineaments trending northeast - southwest.
2.8 HYDROGEOLOGIC SIGNIFICANCES Geomorphology plays a vital role in all hydrogeological studies. Often landforms can reveal the characteristics of near surface unconsolidated formations serving as aquifers such as glacial outwash, terraces and sand dunes. Faults may form impermeable barriers to subsurface flow.
The following facts have been deduced from this analysis:
1.The topographic gradient is gentle. Hence, the hydraulic gradient is expected to be gentle or flat. A flat hydraulic gradient will encourage salinity intrusions depending upon the quantity of freshwater baseflow, recharge and extraction.
2.Any reduction in the hydraulic gradient by overexploitation will salinize the sandy aquifer media.
3.The alluvial channels, coastal zones and river courses are the major recharge horizons. The black cotton soil, by its nature, is not a good media for proper infiltration.
40
4.This area has a lot of rainfed tanks. These have been constructed by the government to meet a portion of water requirement of agriculturists for raising at least one crop after monsoons. Further, the groundwater recharge by these tanks are found to arrested by the silt and sediment loads, including the clay, deposited inside these tanks. These are also the causative factors for floods during heavy downpour. 5.The rain fed tanks could be properly desilted to encourage adequate groundwater recharge.
CHAPTER 3
HYD ROM ETEORO LOGY 3.1 INTRODUCTION HydrometeorologY is one of the important aspects that decides the aquifer recharge. To evaluate the groundwater resources of an area, an in-depth knowledge of all hydrometeorOlogical elements, is essential. These factors not only control the occurrence and availability of groundwater but also the surface run off, feeding of tanks and reservoirs, etc. A proper analysis of the hydrometeorology of a region shaU throw light on the recharge potential of the groundwater occurring in that region. For a systematic hydrometeorological evaluation, the following input data are preparatory. 1 .Nature, spread and extent of rainfall, its intensity vis-a-vis space and time. 2.Evaporatiofl factor and the nature of evapotranspiration, both potential and actual 3.Humidity and temperature variations 4.Surface runoff of the region and 5.Soil moisture content. The causative factors which are the basis for a comprehensive climatological assessment of the available water resources of the subject area are explained in this section.
8
1
I
I
0
I
I I
1z
I CC,
I
• 3 . -6
IIf-)
6
£ =
f
I
I
I
I
'I
-
0 0
Fr'
('4
•.
0 t - u-( 0
c
0 '
<
J-
CD
Z
ci C C)
E 0
0
0
E a
-CI
In
II V
< a.Q =\ WI Ec 0 o E zI
I-.
z\jo
6
II- F a Cl
a
o
ww
IL)
a
ul
I
Li.
fn
Lii
Ix
z
0
IL
a-
cc
W
L)
a-
I-
0
z
z
z
I.-
I
0
Ir
8
00
II
z
o t
42
3.2 WEATHER CYCLE Ramanathapuram District and its coast experiences a dry to moist, subhumid to semi-arid climatic conditions (Ram Mohan, 1984).
Based on temperature and rainfall, the weather cycle of the study area can be classified into four seasons as; (Table 3.1). Table 3.1 Seasons of Ramanathapuram District From Season (a) Hot weather
(b) Southwest monsoon (c) Northeast monsoon (d) Cold weather
March June
To
October January
May September
December February
Generally the coldest part of the year is observed between December and February. The hottest part of a year starts in late Mlarch and ends in June. The southwest monsoon is between June and early October. Northeast monsoon commences from middle October and terminates towards the end of December.
3.3 RAINFALL AND RUNOFF Ramanathapuram District encounters a moderate monsoon rain. Nearly 60-70 per cent of rainfall is contributed by the northeast monsoon. October is the month which receives the maximum amount and June receives the minimum. The average annual rainfall of 9 stations distributed throughout the district has been given in Table 3.2.
With the long term data the average annual isohyets and monthly average bar charts have been prepared (Fig. 3.1). The average annual precipitation of the
o
U)
Ct-,
E
Ct-s 4C Ct - Ct
-
CZ
- 4o I- •
U)
OZI o
U) o
C-)
0 >
0 z 0
0 0
0) (I)
C)
=
CL
Li
CO
c D (t3 a)
II
N- C (N C)
C C C) C) C)
CD
CD
4
(N co
00 C) CD CD
N-
C C
C) - C
(0 LO C)
CD
d
C C)
'-
CD CD N-
(N
CD CD
'- C (N
IC) 0 (N CO -
CO
C CD
N-
C CO IC) (N (N CD ,- I CD N- U) N- CO — N- — CO (NN-CC)U)(NCDCOddLC 10 C IC) CD CD CD U) '- N- IC) C It) C CD IC) It) N- CD IA) 10 It)
N-
N-
(N
CD
CO - N- C)
-1t)
C IC) (N '-
'-CD
CD NN-
C) '- C) '- IC) - C -
(N
cJ CD
CD
IC) N- CO COlO IC) IC) N- N- DCDO (D (D ,NN-I000CDC(-5N-(NC)N0'—C)
(N
C
C
CD (N N- (N CO
C
C - '- (N (N CD CD ,- (N co IC) (N CD (N C (N CD (N CO (N CO (N
(N
CO C 'CD N- (N -'n- CD N- (N (N CD'- (N I0 N- CO CD C N-NCD 4 N-C)C)CD ,- C) CNN-,- CD (N CO (N CO '- -
CD '- IC) (N U)
(N
co
Q C) IC) CD C) CC C) IC) CO 10 - CD IC) CD CO U) co CD
CD ,(0
CD
N-
IC)
C)
'-
CD '- N-
IC)
10
CD
co
IC)
CD CD
'l
(N
'-
(N
IC) (N IC) CO CO
(N
IA) IC) N--
U) - CD
CDC)NC(DIC
U)
N- CD CD
(N
C) (N CO CO (N '- N- (N (N 0 C C (N
'-
C)
C) CO C N- (N CD CO CO CO
(N
IC) IC) IC) IC)
CD
dDC)U),CC)OCC)10CDCD(NCD(N
CO CO
-
CO (N CO Q CD C) CO (N CO
N- CD - N-
N-
CO C)
(N
N- (N
C) (N
CO
CO
0 CO
C C) C)
C) CO C) CO 4 (N CO
CD, (N
CO
10
(N
CD CO
(N
N(N (N (N CD N- IC) (N CO: C CO '- 0) C - C (N 101-0 (N CO CD (N CD - IC) C) - N- It) CO CO IC) IC) 10
(N
It)
1010(D -- - (N C) t CO (N
CO IC) co CD CD 10 co CD: IC) U) IC) CD
IC)
CD CO
C) IC) N- CO CO
CDC)CDCDC)C)(N N-.
CO
CO
CON-N-N-C) C C IC) NN- CO (N CO CO CO
(N (N CO
CO co CO
co CO
C C)
CD CD
CO
CO
CO
co
ca
IC)
U) (UN-CO C) (DC) C CD N- C) I t (N. U)U)CDL0CDU)CON-CDC)C)CD
N-
co
co CD CO
CD U) CD IT 'IT
IC)
N
(N IC) CD(0
CO ITC
(N
IC)
N-
cz
44
-
o a)
> o
z
o o
(/_)
-)
= -
-
o
I
I
)I (EL L
C
Ct'
ci C'
(
N- Co - IL C' C'J
(\J
IC) Co co ci
C\J
C) C Co
(0 0) Co ri c.i
,IC)
CJ
0)
cocJ Q N-
Co ,- N-
Co C"J Co
• C Co IC N Co C'J Co
In N--
d co N-
IL
(0 N-
N(0
(0
IC)
LO C
10 LO (0
(\J
IC) IC) IC) C 10 CO
NCl)
q
IC) IC) (0
(0
I
N-
IC)
(0
(0
(0
N-
co (0
N-
N(0 (0
0 aU>
aCU,
C 0
E E
C) (0
C N--
co
(0
IC)
N-
co
d N-
E = I) >
1)
ca CC
It)
(0
N-
(0
Co
•- N- c
IC)
Co
C'.J
Co
(0
to
Co C'.J
IC) C'J CO
00
C4
(0 ("J
LO C"J
(0 Co C C'i Co
C'
(0 ('J
(0 © Nc'i NC4 ("J
CD
>< cz
CL
C) 0
Co
Co
co
Co
Co
4- >, co C13 . 0 Co
Ct
U)
4-" 4-"
O)i o
(Y,
cu
E
(0 (0 co
Co
N--
C IC)
C'-J C If)
C Q C
co (0 IC) Co
IC) C It)
co
C It)
co
(\J
(0 Co
C
c)
C 0 0 = U) 0
E O)0
0 (0
(0 Q
CJ (\4 Co
c'J
10
IC)
C
N-
(0 N-
N-
co
N--
Co
('4
IC) C
Co (0 ('4
a-
E -
>LI) C C LI)Co
45
46 33 32 31 30 29 28 27 26 25 80 -
RELATIVE HUMIDITY(%)
70 60 50 70
EVAPOTRANSPIRATION (m rn)
60 50 40 30 40
SOIL MOISTURE CONTENT (%)
30 20 10 0 J FM AM J JASON D Fig 3.2. MONTHLY VARIATIONS IN CLIMATOLOGICAL PARAMETERS
district is found to be 89.5 cm. It receives rain from both the monsoons. T southern coast and central portion of the Rameswaram Island, receive apprec able amount of rainfall (101.16 cm); the east coast receives slightly lesser rainf, (82.5 cm) and in the area around Paramakudi the amount of rainfall decreas€ considerably (60.0 cm). Mostly the precipitated water reaches the sea in the fori of run off as the subsurface lithology and soil conditions do not favour muc infiltration.
3.4 TEMPERATURE Table 3.3 and Fig. 3.2 show the climatological statistics based on 10 yea: data (1985-1994) from Parthibanur (PWD watershed observatory). The me maximum temperature falls in the month of May (32.45°C) and the minimul occurs in the month of December (25.3 0 C). The hottest day of the year falls in t month of May (38.8°C) and the coldest day has been experienced in Janua: (2 1. 1°C). After the commencement of southwest monsoon, the temperature decreas€ from the maximum of 32.01°C (June) to 30.9°C (September). During northeast mor soon it further descends to 25.3°C which coincides with the rainfall.
3.5 EVAPOTRANSPIRATION Under field condition it is not possible to separate evaporation fror transpiration. Evapotranspiration includes both evaporation and transpiratic from a bare soil or vegetative cover respectively. In hydrological studies the concept of potential and actual evapotransp:r tion is utilised. Potential evapotranspiration is defined as the quantity of wat
48
that would be removed from a land surface by evaporation and transpiration, provided sufficient water was available in the soil.
Actual evapotranspiration is the proportion of potential evapotranspiration that is actually evapotranspired under existing soil moisture condition.
It is dependent on the unsaturated moisture storage capacity of the soil and vegetative factors such as plant type, dimensions of leaves, and stage of plant.
In Ramanathapuram District, the soils will be wet for a limited period because of restricted rainfall. Actual evapotranspiration is less than potential evapotranspiration because of limited water. For most of the months in an year, water deficiency is a remarkable feature.
3.6 INFILTRATION CAPACITY OF SOILS Soil has a finite capacity to absorb water. Infiltration capacity of soil depends on the factors, viz., vegetation, moisture content, porosity, grain size and burrowing animals.
The study area encompasses soils of less moisture content and low porosity. Most of the parts of the district are occupied by black cotton soil and the long narrow stretch of the coast is occupied by alluvial soil and beach sands. During rainfall, there would be initially high infiltration rate and then a gradual fall is expected. After sometime the entire rainfall would flow on the surface in the form of run off.
49
3.7 OTHER METEOROLOGICAL FACTORS 3.7.1 Relative Humidity The absolute humidity of a given air is the number of grams of water per cubic metre of air. At any given temperature, air can hold a maximum amount of moisture; i.e., the saturation humidity.This is directly proportional to the temperature of air. The relative humidity for an air mass is the per cent ratio of the absolute humidity to the saturation humidity for the given temperature of the air mass. Evaporation would cease, when relative humidity approaches 100 per cent (Fetter, 1988). In the study area, the relative humidity is around 78% and the mean temperature is 26°C (January). Relative humidity decreases to 52% when mean temperaturE varies to 32°C (June). As the monsoon commences. it gradually increases anc attains a maximum of 80% (November). The mean annual is 65.42%.
3.7.2 Soil moisture content The water content of the soil is known as soil moisture content. It is thc ratio of the contained water to the total weight of the soil mass and it is expressec in percentage. Soil moisture content of the study area varies from 11.26 % (July to 32.7 % (December). Annual average is 13.86 %.
3.7.3 Wind velocity The average lowest wind velocity in this area is 2.05 kmph (February) an( the highest is 7.87 kmph (July). The annual average wind velocity is 3.88 kmph.
50
3.7.4 impact of meteorological factors on hydrology The average annual rainfall of the study area is 895.7 mm which is less than the state average rainfall of 942.8 mm. The prevailing higher temperature enhance the evaporation of surface water and also the actual temperature. From the relation between the rainfall, potential evapotranspiration and actual evapotranspiration, it is inferred that the water is deficient and in the overall area aquifer recharge is less.
5]
CHAPTER 4
HYDROGEOLOGY
4.1 INTRODUCTION The governing factors like the morphometry of a hydrological regime, levels of absorption by the sub soil and the surface vegetation and loss on account of evapotranspiration determine the quantum of water accruing to a region.
On the other hand, factors like relative runoff and recharge, drainage which is indicative of lithologic and structural controls, the geological stage of formation and erosional features may highlight the hydrological aspects of groundwater occurrence as well. The present section deals with the groundwater conditions in this coastal stretch including a description of the aquifer types, parameters and the behaviour of the system.
4.2 THE NATURE OF AQUIFERS An aquifer is a water bearing reservoir capable of yielding enough water to satisfy a particular demand (Driscoll, 1986). To be more precise it is a rock with a good porosity and permeability. Alluvial and glacial deposit of sedimentary origin and weathered metamorphic and igneous rocks form good aquifers.
52 Sandstones are the most important reservoir rocks for storing large volumes of groundwater.
Limestones with secondary features like solution cavities may form good storage media for groundwater. Shale and clay virtually have no storage space for groundwater.
Igneous and metamorphic rocks are normally affected by weathering when they are subjected to aerial agencies. Gradually, they become fractured, jointed and faulted. Only the weathered zones and shear zones of hard rock terrain can form good aquifers. Alluvial beds or the earth fill between the lava flows and open lava tunnels form a good reservoir for groundwater.
As the present study area encompasses a gneissic complex and sedimentary rocks, the occurrence of groundwater varies with reference to the hydrological characteristics of these rocks.
4.2.1 CRYSTALLINE TERRAIN
The porosity of crystalline igneous and metamorphic rocks have been worked out by Meinzer (1923). Rarely the primary porosity exceeds 2% in crystalline rocks. Weathering and fracturing may contribute to secondary porosity. The thickness of weathered zone may be anything from a few mm to a few tens of metres in these terrains. It depends on the duration, the rock has been exposed to weathering and the action of climate. Fractures may persist to the depths of 300 m or more, with decreasing intensity. Usually the secondary porosity may range from 1 to 6 per cent and rarely exceeds a per cent of 10.
53
I
se
4 no
is
•' TLC
Al
VP -
d
-
P1.NO4COFALLINE LIMESTONE AT RAME5WAEAM ISLAND.
T
54 Permeability of crystalline rocks varies widely, depeqding on the degree of weathering, nature of weathered material, intensity of fracturing and open spaces in fractures. The western region of Ramanathapuram District has the aquifer made of crystalline rocks. Mostly they are biotite gneisses and in some locations it has been observed that there is a change in the mineral content from biotite to hornblende. Areally, the crystalline terrain works out to be less than 10%. In other parts of the district it occurs at various depths ranging from a few tens of metres to a few thousands of metres as discussed earlier. Hydrogeologically large diameter, partially or fully penetrating dug wells are located in hard rocks and the bore wells which encounter in these hard rocks are of varying depths and found to be having low yields. 4.2.2 Sedimentary terrain Nearly 95% of this district is constituted by sedimentary terrain. Mainly they are silt, sand, clay, gravel, kankar and sandstone. In most of the bore wells, calcareous sandstone is encountered. In Rameswaram island, surface exposure of fossiliferous limestone is noticed (Plate 4). In sedimentary rocks, the porosity and permeability depend on the degree of compaction, cementation and recrystallisation. Porosity of sedimentary beds ranges from 10 to 30 %. At deeper level it becomes less due to compaction and due to the over burden. Wells located in the sedimentaries are found to be of having good yield. The alternate sequence of sandstone and clay g ives rise to artesian aquifer condition in some parts of the study area. Artesian aquifer of Tiruvadanai area is found to show a high groundwater potential.
55
4.3 GROUNDWATER FLOW Groundwater flow depends on the following physical properties, viz, water transmitting properties of the medium, physical properties of flowing water such as specific weight, density, viscosity, temperature and compressibility.
The specific weight is the weight of a substance per unit volume at a particular temperature. Density is the mass per unit volume. Viscosity is the resistance of a liquid to flow. These features control the groundwater flow.
4.3.1 Hydraulic properties of porous media
Groundwater moves in the direction of decreasing head or potential. The movement depends on hydraulic conductivity (k). It is defined as the capacity of a porous medium to transmit water. Hydraulic conductivity is governed by the size and shape of the pores, the effectiveness of the inter connection between the pores and physical properties of the fluid.
Another factor which has a high practical value is the aquifer transmissivity. It is the rate of flow (in gallons per minute or other similar units) through a vertical section of an aquifer, one foot wide and extending the full saturated height of an aquifer under a hydraulic gradient of 1. In the international system of units, transmissivity is expressed in cubic metres per day per metre (m3IdIm) or metre square per day
(M2
/d).
These factors can be determined by using the data collected during pumping tests. The coefficient of transmissivity established during pumping test is more accurate and reflects the hydraulic conditions within an aquifer system.
The most important water bearing formations in Ramanathapuram District are the younger recent to subrecent sediments. Year after year the yield of water wells gets reduced and the government had to drill a set of new bore wells nearer to the old ones extending to a greater depth. This is due to the presence of thick or thin series of semi pervious layers and also due to the alternating layers of clay and sand. Some of these beds seem to be discontinuous, with varying dimensions and structures. This consequently may change the rate and extent of groundwater availability. Quite a lot of favourable conditions exist for surface recharge and for adequate infiltration. The entire population depends on the groundwater available in the quaternary series and a guaranteed source of groundwater could be expected only along the alluvial horizons. In view of this geological situation, the following types of subsurface water could be distinguished for proper water management. Shallow groundwater zone: This is the horizon situated closest to the surface and the horizon which is in general under atmospheric pressure and most directly influenced by the hydrometeorOlOgical factors. Under natural conditions. the principal source of recharge is from precipitation, in which the losses may be mainly due to evapotranspiration. The water budget of this horizon is influenced mainly by lateral inflows and outflows. Bank filtration water: This is also of the shallow zone expected in th€ vicinity of the bank strips, adjacent and along the rivers. This is influenced mainI by the river regime. The water budget is controlled by the infiltrating precipitatior (as supply), in part by the water supplied, or drained by the rivers depending or the variable relative positions of the groundwater table and the water level in thc river stage, which is only a seasonal phenomena.
57 Pseudo-artesian/artesian waters: These are defined as the waters combined in the sandy gravel strata separated by lenticular (?) clay layers within the quaternary sedimentary terrain. The system is in direct communication with the groundwater, which may be the first water bearing layer below the terrain. As deduced from the litholog data, in the vertical profile, the aquifers appear to be layered. These are seem to be practically dynamic resources, the water of which gets recharged from upstream sources. Deep groundwater system: In Tamil Nadu State, this area is the second major and deeper groundwater system, and the other one is existing around Cauvery Delta (Sathyamoorthy, 1984). Earlier attempts by Sastri and Lawrence (1988) and Sathyamoorthy (1991) under these environments, revealed that the quality of water in shallow aquifers are unique when compared to the deeper ones. This indicates that the deeper horizons may have the impact of salinisation or otherwise due to the adjacent seawater and the hydrogeologically varying vertical profile of sedimentary strata.
4.4 SALINE INTRUSION IN COASTAL AQUIFERS Excessive groundwater extraction due to urbanisation, agriculture and industrial development causes saline water intrusion in coastal aquifers all over the world. 4.4.1 Coastal hydrogeology Coastal hydrogeology is represented by an unconfined, island or confined aquifer. In coastal zones, freshwater body will overlie the saltwater body because the unit weight of freshwater (1 gm/ml) is less than that of saltwater (1.022 to
1.031
gm /ml). The boundary surface between the two types of water is known as
the saltwater-freshwater interface or the interface. The hydrodynamic balance of the fluids governs the shape and movement of the interface. If the coastal zone consists of two or more distinct layers, each aquifer will have an independent interface. The transition between the saltwater-freshwater interface need not be a sharp one but has been found to be a dispersed zone through field investigations. Cooper (1959) and Kohout (1964) have shown that in the zone of mixing, the diluted seawater is less dense than the original seawater, causing it to rise and move seaward along this interface. This involves a cyclic flow of saltwater from the sea through the ocean floor, to the zone of mixing and back to the sea. This cyclic flow occurs even under steady-state conditions. Due to pumping of fresh groundwater, the natural equilibrium is disturbed and the saltwater moves inland until a new equilibrium is established. Conversely, an increase in freshwater flow pushes the interface seaward. The location, shape and extent of the diffused zone depend upon several factors including (1) the relative densities of fresh and saltwater, (2) the rate of discharge of groundwater, and (3) the dispersion and hydraulic parameters of the aquifer.
4.4.2 Basic principle The basic principles of saltwater-freshwater relationships in coastal aquifers have been presented and discussed in many text books on groundwater hydrology (Todd, 1980; Freeze and Cherry, 1979; and Kashef, 1986). Ghyben (1889) developed an analytical expression for the location of the sharp interface and Herzberg (1901) arrived independently at the same con-
59
ii
h
Flg.4.1 THE GHYBEN-HERZBERG INTERFACE MODEL h 1 Fresh water head, h 5 Depth to interface below sea level
clusion. Their formula relates the elevation of water table in an unconfined aquifei to the elevation of the interface between salt and freshwater (Fig. 4.1). It is knowr as the static equilibrium principle and is written as
z=
,Of4. h Ps Pi
where p f is the density of freshwater,
ps
is the density of saltwater, and z i
the depth below sea level to a point on the interface and h is the water tabl€ elevation above sea level at that point.
The Ghyben-Herzberg equation formed the beginning of all quantitativE analysis. The dynamics of saltwater interfaces were clearly stated through the work of Muskat (1937) and Hubbert (1940). Both researchers showed that the con tinuity of pressure in the flow field must be maintained across the asssume interface. Therefore, the interface could be treated as a boundary surface tha couples two separate flow fields.
Hubbert (Op. cit.) showed that if a potential function (head) is defined fo each fluid, then the equation governing the interface can be derived by defininç the freswhater head (h i) as:
--+z
hf PS
and the saltwater head ( h e) as:
g
4.
61
h =
.4.3
+z S
where z is the elevation (above a datum) of the point at which head is measured; p is the fluid pressure at the point of measurement and g is the acceleration due to gravity. These two expressions can be written for the pressure at a point on the interface. As this pressure is the same for both the cases, equating these expressions gives: Pf
z=
h1—
PfP5
..4.4 PS _______ h5 PfPs
Glover (1959) developed a formula to describe the sharp interface in a coastal aquifer accounting for the movement and discharge of freshwater. The interface position can be plotted from his expression. 2
Y
2 -
-
=0
45
where 0 is the freshwater flow per unit length of shore (L 2T); K is the - (dimensionless); p 5 is hydraulic conductivity of the medium (LT'); r = the density of the saltwater (ML
-3). 5
pf
is the density of freshwater (ML3); X is the
horizontal distance (L); and y is the depth from mean sea level (L). Glover's exipression allows for discharge at the shore and balances pressures across the interface. The width of the gap through which the freshwater escapes to the sea is expressed as:
Q xo =;
.4.6
Any increase in the flow widens the gap. Tidal action causes a diffusion of saltwater across the interface. The salt is carried back to the sea with the freshwater flow. Cooper (Op. cit) developed an hypothesis to explain the mixing zone of dispersion and the associated circulation of seawater, observed in various field investigations. His explanation is that the seawater and freshwater become intimately mixed in the zone of diffusion by the mechanism that creates this zone. The diluted saltwater having become less dense that native sewater rises along a seaward path. Meanwhile, the salt that is introduced into the freshwater environment are carried back to the sea by the flow of the freshwater system. Henry (1959) developed some numerical solutions for determining th€ sharp interface under various boundary conditions. He was one of the first in vestigatOrS to solve the coupled flow and mass transport equations for a steady state, idealised confined aquifer by means fo Fourier-Galerkin double .serie expansion. He included the effect of dispersion in a confined caostal aquifei under steady-state conditions. As his approach quantitatively accounts fo hydrodynamic dispersion (or mixing) it provided a firm direction for all futurc advancement. Most of the mathematical models developed for saltwater intrusior prediction use Henry's data for verification.
63 4.4.3 Salt water sources In any coastal area, seawater forms the main source for saltwater encroachment and the other sources of water are:(1) Seawater that might have entered during sediment deposition or during a high stand of the sea in the geologic past, (2) concentrated salt beds of various types in geologic formations, (3) saline water concentrated by evaporation, and (4) man's domestic industrial and agricultural wastes.
4.4.4 Mechanism at intrusion Basically there are three mechanisms by which saline intrusion takes place. They are: (1)The reversal or reduction in the groundwater gradient, which allows heavier saline water to move into an underground zone where only freshwater existed earlier. (2)The accidental or inadvertent destruction of some natural barriers that formerly prevented the movement of salt waters or separated the bodies of fresh and salt water. (3)The disposal or spread of saline water over land along the coast for salt production or intensive coastal aquaculture.
6 One of the typical example of destruction of natural barriers is the construction of coastal waterways or embayment. When natural water ways are deepened or widened there may be removal of material Which might have acted as a barrier in the past. Due to removal of confining bed or well drilling, saline water may move vertically along broken or eroded well casings to contaminate fresh aquifer.
4.4.5 Numerical approximations
While applying the earlier theoretical concepts, field investigators learned that not all coastal systems behave in accordance with some of the formulations. Several attempts have been made to analyse numerically the interface position and its motion in the coastal aquifers. Detailed descriptions of these basic principles and a review of the quantitative methods of analysing saltwater-freshwater interface relationships in groundwater systems are given in Reilly and Goodman (1985).
Approximate expressions for the motion of the interface in .a confined aquifer have been developed and verified through experimental studies by. Bear and Dagan (1964). Numerical solutions of the steady sharp interface in a confined coastal aquifer using the finite-element method have been attempted by Cantatore and Volker (1974). Experimental verification of their results was also provided. Mualem and Bear (1974) developed analytical solutions and experimentally verified the shape of the interface in steady-flow in astratified aquifer. Shamir and Dagan (1971),Van der Veer (1977 a,b), Vappicha and Nagaraja (1976), Bear and Kapular (1981),Kishi et al. (1982), Kashef (1983), Kemblowsk (1985), and Savenije (1989) have all developed simple solutions for the deter-
65
SURFACE
G
I - - --
STATIC WATER LEVEL BGL ------WATER TABLE I
N
N
-
-
N
\
\
-
\
WELL DEPTH
U
SALT WATER
WHERE U = RATE OF PUMPING L
DEPTH OF THE INTERFACE BELOW WELL SCREEN
K
PERMEABILITY
7 ' RISE OF SALTWATER INIEUFACE
Fig. 4.2 UPCONING IN SALTWATER
mination of the interface position and shape, and have attempted to verify thE results with either field or experimental evidence. Volker et al. (1985) studied the transition zone within groundwater or ocean atolls with variable stress conditions.
4.4.6 Analysis of saltwater upconing The change in the normal salinity distribution in coastal aquifers due tc pumpage is often described as an 'upconing' of the interface between saline an fresh groundwater (Fig. 4.2). The dispersion of salinity in the aquifer affects th upconing process. Several attempts have been made to analyse this probleir Detailed descriptions, numerical principles and methods of analysis can be see in Ackermann and Chang (1971), Streltsova and Kashef (1974), Haubol (1975),Kashef and Smith (1975), Rubin and Pinder (1977), Das Gupta (1983) an McElwee and Kemblowski (1990).
4.5 WATER LEVELS Normally any groundwater system would be dynamic. The disposition ( water levels in the aquifer environment mainly depends on recharge. WhenevE there is deprivation of recharge, there would be a declination in water level due t the decrease in storage.
Storage is the ratio of the storage upstream of any cross section to tb flow past the section; it thus has the dimensions of time. If the ratio is sufficient large to damp out fluctuations in recharge, the hydrology becomes a relative simple problem of steady flow analysis. A ratio of fifty years in the arid zone ar
67
Pudukottal Dt.
Fig. 14.30 RAMANATHAPURAM DISTRICT GROUNDWATER LEVEL (Pre monsoon)
N
O) '0
P.M .1 Dt
Control well
(4 06
Kamarajar 0 .
INDEX
1.
35 -• Palk ubay 30 •o
-5 Water table contour( in m)
13 16
16 0017
1 18 0
9.
20
019
2
.2
Gulf of manaar
2
o
Chidambara -nar DI.
5 io
INDEX
2 0
P.M.T DI. Kamaraj
1.
®6
8
35 3
N
Pudukottai Dl.
Fig. 4.3 b RAMANATHAPURAM DISTRICT GROUNDWATER LEVEL (Post monsoon)
Control well 115 1/ Water table contour In m)
Polk bay 25
013 11.
165
25
9 5
23 0
2
Gulf of manaar
5 Chidamba -nor Dl
®17 11
018
10KM
21 9
Fig.
Fig
79' 1001
7830'
N
Pudukctt DL
4.4a
RAMANATHAPURAM DISTRICT ____ DEPTH TO THE WATER TABLE 2 (bgl) JANUARY ______________ P.M.T Dt.
Water table (m) '.
llD 5 P Control well
5
Gulf of manaar
- 25
Chidambaru -narDt.
1
18 -19
0 5 10KM I I
26
.4.4b RAMANATHAPURAM DISTRICT DEPTH TO THE WATER TABLE (bgi)OCTOBER
N
Pudukottai ______ DL 0
2 .
9.
INDEX Water table (m)
Eg
Polk bay 13
12
P —1
1 • - 1
20
•19
Gulf of manaar Chidamba -nor Dt
0 5 10KM I
78130'
7911 00
Control well
6 rather less in more humid area is generally sufficient for this purpose. If the ratio is small, five years or less may have a remarkable effect on groundwater levels. To determine the storage a thorough knowledge of the specific yield and hydraulic conductivity of the aquifer, its thickness and extent of up gradient, the hydraulic gradient and the application of Darcy's Law are essential. However, even if accurate values are not available for the various parameters, reasonable approximations can be made which can give some meaningful results. For a unit width of aquifer, the storage up gradient of a selected section is given by the product of thickness and length of the aquifer and its specific yield; the flow is given by the product of the thickness of the aquifer and its hydraulic conductivity and hydraulic gradient. 4.5.1 Depth to water table in wells Generally,the depth to the water table is controlled by the topography of the area, surface water body and recharge due to rainfall. Close to the elevated zone the water table lies comparatively at higher attitude than the valleys. Other than topography, subsurface controls like dyke and other structures will also influence the position of water table. The long term water table data of 26 control wells have been processed for the preparation of maps. The premonsoon (October) and post monsoon (January) water levels have been identified and the water table maps were prepared (Figs. 4.3 a & b and 4.4 a & b). These figures can indicate the effect of recharge after monsoon. The depth to water level varies from 2 to 7 m bgl in post monsoon and 3 to 9 m bgl in pie monsoon period. The water level is deeper in the western part of the area (i.e. around Kamudi and Abiramam). Near the coast the water level is
relatively shallow. At control well no. 5 (R.S Mangalam) it is shallower. This ma be due to presence of the largest rain fed tank near R.S. Mangalam. From thE isohyetal map, it has been found that the north western region receives the leas rainfall. The impact of that has been in the water table map too. In and arounc Ramanathapuram, the extraction seems to be more and that would be the reasor for having the deeper water levels. The following facts have been deduced from the comparative study o premonsoon and post monsoon water level contours. 1 .The groundwater flow is from north to south in the western region an northwest to southeast and east in other areas. 2.A detailed study of long term measurement illustrates that the highes water level is seen in December/January and the lowest is noticed in Septembe /October. 3.The water level rises due to northeast monsoon? 47he gentle groundwater gradient nearer the coast indicates that th velocity of groundwater flow is getting reduced nearer the coastline. 5.The northern part of the District has not shown any variations in watc levels of pre and post monsoons. The artesian condition prevail only in th northern part of this district.
4.5.2 Water level fluctuation According to Davis and Dewiest (1966) water level fluctuation could b due to the following factors: (1)deformation of aquifers, (2)internal factor such as chemical or thermal change, (but it would be in smaller scale),
.
71 -
(3)change in groundwater storage (recharge and discharge) and (4)change in atmospheric pressure. An average annual water level fluctuation map has been prepared from the long term data (Fig. 4.5). The average annual fluctuation of water level is found to be very less (1.0m) in the following locations: (1)Rameswaram Island (Loc. No.21 & 22) (2)Oriyur, Tiruvagampet and R.S. Mangalam (Loc. No. 1, 2 & 5) (3)around Parthibanur (Loc. No-7) (4)area around Kadaladi (Loc. No.24) and
the
(5)area around Sayalkudi. This may be because of high annual rainfall in Rameswaram Island, and in other locations it may be due to less abstraction of groundwater and the area may be coming under a discharge zone hydrologically. In the entire study area, aquifer zones around Tiruvadanai have shown the maximum amount of fluctuation (3.5 m). This may be due to the over exploitation for agricultural purposes. In the remaining region the fluctuation is moderate. It is of interest to note that a sort of effluence is seen along the stations numbered 15, 16, 18 and 19, during premonsoon period. This indicates that the hydraulic gradient gets modified during that period.
The normal depths to the water level in wells during January and October have been depicted in figures 4.3 a & b and 4.4 a & b. It is found to be shallow only at a few places.
As January is the post monsoon period, the depth to the water level ranges, in most of the area, from 2 to 5 m. A deeper water level is seen in the crystalline terrain and in the extreme northern corner.
72
78' 130
udukotta/ DL
Fig .4.5 RAMANATHAPURAM DISTRICT AVERAGE ANNUAL WATER
N
2
INDEX
LEVEL FLUCTUATION
ED P.M.T DI.
lllhI1ll1 10-20
20-30
8
Kamarajar ot.
-
__
>30 Control well
Polk boy
13
____
20
0 5
jfZ^^
anr
Gulf of Chidambaru
9.
0 I>-
M
0
0
0
Iii I 0 >w >
0 U U z 0 >(I, U
U U
U U IL LI)
(I) 'I U I= U -j
IL 0 0 I
LU co co
IL
Singhal (1973) suggested that since both the diameter and the saturated thickness of aquifer trapped vary, it would be better if the Slichter's specific capacity is divided by the total contributing surface area of the aquifer tapped by the well (lpm/m drawdown/sq.mt of total surface area tapped). Limaye suggested during 1973, International Seminar on Groundwater Development at Madras, that instead of the use of total contributing surface area of the aquifer tapped, it should be a sum of the total surface area of the well under study. The modification of Limaye (lpm/m dd/sq.mt ) has been taken into account for discussing the aquifer properties.
It could be seen (Fig. 4.8) that in this coastal zone the Slichter's specific capacity in almost all the wells examined, decreases with increasing recovery time denoting the poor yielding nature of the aquifers. This is expected in the coastal zones where clay layers intercalate with sands, sandstones and shales.
4.6.4 Time for full recovery analysis
Rajagopalan
et
al. (1963) have (i) carried out tests on open wells under
constant well discharge conditions (ii) recorded the drawdowns during pumping and recovery phase and (iii) analysed the data using two approximate equations derived under conditions of two alternative assumptions made on the distribution of the hydraulic gradient in the aquifer (at r- radius of the well itself) and under the condition of an additional assumption that the hydraulic gradient at the wellface is linearly related to the drawdown within the well diameter,
log s
log
KBt + log s0
= - •
4.27
2D—s = __i!_ D KEt + Jog 2D-so/so ..... . 4.28 1.1515 r S
where, rw = radius of the well D = the depth of water column in the well prior to pumping K = permeability of the aquifer s = drawdoWn within the well diameter = time since recovery started so = drawdown at t = 0 and B and E are constants (all units in Metric system).
As has been pointed out by them. the equation 4.25 is incidentally of the same form as that given by Slichter (1902) and Basak (1982) and the equation 4.26 is incidentally of the same form as that given by KumarasWamy (1973).
If equation 4.25 is to be used, then the recovery data should be plotted or semilogarithmic graphs keeping S 0
on logarithmic scale. The slope of the result-
ing straight line is equal to
1.1515 r
and substituting the values D and rw determined.
KB...................
42
the numerical value of DB can b
10
To use the equation 4.26, the recovery data should be so plotted that left ({2D-s} over s right) is on the logarithmic scale and t on linear scale. The slope of the resultant straight line is equal to 1
D4.30
—KE 1.1515 r
and substituting the values for D and r w the numerical value of the parameter KE can be calculated. In both these determinations it should be remembered that the numerical values of KB or KE are not unique for a particular dug well, but is actually a function of the well discharge conditions during the abstraction phase (Rajagopalan, 1982'. The wells could be considered to have fully recovered if s = 0.01 D. If the equation 4.25 defines recovery within the well diameter then the total time required fcr full recovery can be computed using 1.1515r tfr"Max) = 0KB
100s0 log
2.303r tfr(max)
4.31
0KB
If the well is cewatered completely and if 8 0 = D, then
If the equation 4.25 defines the time required for full recovery within the well diameter, then
io:
1. 1515 r w
tfr( mW ) =
-,---
100(2D-0.01S0)
.4.32
log ------
If the well is dewatered completely then,
1. 1
515 rw
tfr(mX)
4.33
log 199.0
It has been concluded that (i) for the same conditions of D. 0 and ttr(max) are directly proportional to r w
and (ii) for the same conditions of r, 0 is directly
proportional and ttr(max) is inversely proportional to D. Table 4.5 gives the computed tfr of this area
4.7 POTENTIALITY OF AQUIFER 4.7.1
TransflhiSSiVItY The transmisSiVitY and storage coefficients are important factors as they -
determine the hydraulic characteristics of any water bearing formation. The coefficient of transmiSsiVitY indicates how much water will move through the formation and the coefficient of storage indicates how much can be removed by pumping or draining. If both of them can be determined for a particular formation then the following prediction can be made successfully; (1)DrawdOWn in the aquifer at various distances from a pumped well,
(2)drawdOwn in a well at any time after pumping starts. (3)how multiple wells in a small area will affect one another and also the whole system and, the
103
Table 4.5 Time for full recovery
Well No
Recovery rate
Sat. thick (m)
Equ. radius (m)
KB
KE
Time required for full recovery KE
Optimum yield
KB
Th31d
4.0
74.90
0.08
-0.0338
1.1300
1.13
1.00
10.55
2
1.7
54.35
0.08
-0.0083
0.0085
4.52
4.04
4.13
1.4
54.30
0.08
-0.0224
0.0225
1.70
1.49
4.20
3 4
0.5
40.25
0.08
-0.0040
0.0041
9.26
8.27
1.63
0.2
20.90
0.08
-0.0031
0.0032
12.04
10.67
7.54
5
1.2
62.85
0.08
-0.0241
0.0242
1.58
1.38
6.59
6
1.9
36.63
0.08
-0.0546
0.0550
0.70
0.61
301.16
7
1.8
65.40
0.08
-0.0165
0.0166
2.30
2.02
6.89
8
2.9
76.45
0.08
-0.0027
0.0028
13.59
12.48
0.78
9
0.6
75.45
0.08
-0.0060
0.0060
6.34
5.56
3.14
10
4.6
47.40
0.10
-0.0031
0.0035
11.06
10.78
0.52
11
2.6
44.10
0.08
-0.0140
0.0142
2.69
2.38
12.02
12
4.0
40.18
0.08
-0.1306
0.1315
0.29
0.26
8.56
13
0.4
34.00
0.08
-0.0056
0.0052
7.41
6.51
29.83
14
1.3
10.92
0.10
-0.0068
0.0071
5.36
4.73
988.21
15
0.6
35.00
0.10
-0.0099
0.0099
3.86
3.38
103.74
16
0.2
65.25
0.08
-0.0011
0.0012
33.30
20.09
2.84
17
4.5
50.20
0.10
-0.0133
0.0135
2.85
2.51
16.04
18
0.9
66.15
0.08
-0.0295
0.0296
1.30
1.13
4.93
19
5.8
136.20
0.08
-0.0227
0.0228
1.68
1.47
9.50
20
1.3
10.00
0.10
-0.0084
0.0086
4.46
3.97 339.93
21
0.9
37.80
0.08
-0.0382
0.0383
1.00
0.87
97.87
22
1.0
42.20
0.08
-0.0256
0.0258
1.49
1.30
4.55
23
2.8
30.76
0.10
-0.0218
0.0222
1.73
1.53
205.00
24
3.08
0.70
-0.0104
0.0119
3.22
130.81
39.9
3.21
25
0.8
9.10
0.08
-0.0224
0.0230
1.66
1.49
251.60
26
46.2
3.75
1.75
-0.0065
0.0067
5.72
5.12
181.22
27
28.50
0.10
-0.0095
0.0096
3.99
170.53
0.5
3.51
28
0.3
89.10
0.08
-0.0074
0.0074
5.18
4.52 340.26
29
5.9
70.50
0.10
-0.0236
0.0238
1.61
1.41
30
15.96
104
105
106 (4)drawdown in the aquifer at various pumping rates.
With the computed transmissivity, a contour map has been prepared (Fig. 4.9). It could be seen that the zones of high transmissivity fall in the area east of Abiramam (Loc. No. 15) and south of Kadaladi. High T exists along the boundary between crystalline and sedimentaries and also along the southern coast. In the central region and the entire Tiruvadanai Taluk, the values are found to be low. The clay layers and black cotton soil may be the causative factors for a low 4.7.2 Optimum yield - Output results For any groundwater development programme it is essential to determine the optimum yield of wells. Sammel (1974) has analysed the various methods of aquifer test and reviewed the deficiencies. Karanjac (1975) suggested a method for finding out the optimum yield. as
-
tp tp+tfr(max)
.................. 4.34
where 0 0 optimum yield in m 3 /day; Q = discharge rate of pumping in m 3 lday; tp = time duration of pumping in days and tfr = total time required for full recovery. With the output a map has been prepared (Fig. 4.10). The optimum yield of the wells are mostly found to be low (less than 100 3 ,d) except a few locations.
107
108 4.7.3 Time for full recovery in wells With the calculated values, a contour map showing the time for full recovery (Fig. 4.11) has been prepared. It has been found that most of the wells require less than 8 hours for full recouperation. The higher tfr zone existing around Gopalapuram (Loc. No. 17) suggests the presence of a hard rock. Region around Odikal (Loc. No-9) could be considered as a poor quality aquifer.
4.8 COMPUTING THE LENGTH OF SALINE INTRUSION If the water table gradient of the coastal zone is measured then the slope of the interface could be computed by considering Darcys law and the equation,
sin -
dhhV
..........4.35
where, i is the gradient, V is the velocity of freshwater flow and K is the permeability of the media. As this slope, the water table elevation also decreases along the direction of groundwater flow. Accordingly, the fresnwater saltwater interface should rise towards the mean sea level. The slope of tne inteace 0 is governed by fif
V
= -
sin 0 =
...............4.36
Ps - Pf
The boundaries of both the slopes (i and 0) at the coastline result in a parabolic interface. This shape is assumed to be similar to the Dupuit'S parabola and is given by Rumer and Harieman (1963).
109
20000
15000 E z
0 Lt)
10000 LL 0 I
z U
II,
10
20
30
40
50
60
70
AQUIFER THICKNESS (m)
80
90
ioU
(After Subrnmanan 1994)
Fig. 4.12. NOMOGRAM SHOWING THE LENGTH OF SALINE INTRUSION IN COASTAL AQUIFER.
110 (2 Y
[2 ()
x
+ 0.55
.4.37
where, K is the permeability, q is the sea ward freshwater flow per unit width of the ocean front and y is the co ordinates of the interface with the origin at the coastline. Along the coastline, considering x as the distance from the coastline, it was found that at Y = 0, X =
-0.275qIK'
where K=K9K(G_1)0.025K ........4.38
where G is the specific gravity of saltwater. The total length of intrusion (L) can be computed (at X=0) using, L = (K' H 2 )/2q ,when L > H. Subramanian (Op. cit.) prepared a nomogram (Fig. 4.12) showing the length of intrusions computed using different sets of aquifer q, K and H values. The length of intrusions for this coastal zone is expected to be ranging from 14000 to 15000 m. This is obtained by considering a K value of 10 m /d and q of 1.0
M3 /d, for an aquifer H of 80 m.
4.9 WELL DESIGN
While designing a well in any coastal terrain the following aspects are to be taken into consideration;
(I) groundwater potential, (ii) water table fluctuation and the (iii) saltwater-freshwater interface.
The aquifers of Ramanathapuram District are found to be yielding less M2 /day in most of the locations. Considering the salinity problems it is than 300 desirable to have large diameter dug wells. The average diameter recommended is 4.5 m.
For limited extraction filter points are desirable (30 1pm). Large diameter M3 /day). To infiltration with radial arms may suit a moderate extraction (20 to 30 meet a still higher requirement, a well field with 10 to 15 feeder wells and a large M3 /day). In coastal aquifers the diameter collector well is needed (50 to 100 pumping rate should be as low as possible, so that the drawdown will be less and gradual, which will avoid sudden upconing of the interface.
Nearer to the shore, where freshwater thickness is limited, it is preferable to have a shallow open well with its bottom sealed and radial arms positioned in the freshwater lens with suitable gradient. The specific capacity of wells can be increased by having more horizontal filter points.
While designing a tube well in coastal areas well log is highly informatic. From the results obtained through geophysical studies, it may be possible to infer the top and bottom the aquifer containing the potable water.
112
CHAPTER 5
HYDROGEOCHEMISTRY 5.1 INTRODUCTION It is a well known hydrogeological fact that water occurring in nature is never found in its pure form. Any sample of groundwater will disclose the presence of chemical ions, the nature and intensity of which depend upon the source of groundwater, rate of its movement which controls the residence time and the soil or rock through which the movement occurs. Only after ascertaining the physical, chemical and bacteriological qualities of the samples, the suitability of any water can be determined for different purposes. Following are the broad aspects of the hydrogeochemical studies pertaining to any area of investigation.
(1) Establishing the geochemical patterns.
(2) Developing a hydrochemical model.
(3) Identification of the facies of the groundwater system. (4) Establishing the possible ways of using the groundwater. The finding that results out of an indepth hydrogeochemical study could yield much information of high utility for a variety of purposes.
113
5.2 CHEMICAL CHARACTER OF WATER Water has the ability to dissolve a greater range of substances than any other liquid. A slow percolation of precipitated water through the ground results in prolonged contact of water with the minerals in the soil and bed rock. Some minerals are dissolved slowly as groundwater passes over them and in due course an equilibrium condition is established between the minerals in the soil, rock and the groundwater. Sometimes, the water is over or supersaturated with certain dissolved species derived from the minerals. This ability of water to dissolve minerals determines the chemical nature of groundwater.
In contrast to the surface water, most groundwater contains no suspended particles and practically no bacteria or organic matter. It is usually clear and odourless. It ordinarily contains more dissolved solids. Some of these dissolved minerals are essential for good health. A complete chemical analysis may determine the groundwater suitability for domestic, agricultural and industrial use. An analysis includes hardness. specific electrical conductance, hydrogen ion activity and total dissolved solids. Each of these properties is useful in evaluating the chemical character of groundwater. An increases in temperature usually increases the solubility of most minerals. Near the surface, the groundwater has the temperature almost equal to surface atmospheric temperature. Due to geothermal energy, groundwater at depth may show a higher temperature. Therefore most of the groundwater obtained from deeper wells are more mineral is ed.
In coastal regions, groundwater is abstracted from shallow small or large diameter wells and through deep bore wells.
(I) C I-
0
(I)
oH co ci 1. c
Li
Q1O (j
cI 01
cz
oi
1
C_F C)i cz
(i ci
Ct I
U)
Lu
(J,
U) 1 U)
ca
9.
E z wio a) Ct 0 I-iZ 1
co U) C U) U) U) C) U) co C U) C U) NT CO (N C) (N C U) U) U) - - (N U) U) (N U) U) (N - C (N N N- - CO(N N-C CO (N (0 (D C U) C U) (N CO C U) ,'- '- (NLO Cl) U) N C .- (N ,- N- - ,- '- (N
N-
(N
TT
C N-
U) NN CO CO 0) CC)U)CO(N (D U-)
LU U) (b L6 C'J In
C U) C C C (N U) U) U) C U) C xD C U) C C C C C C C dc6 d d doi N C)CU)CU)CU) 4 CCC C CCC U) (N (N '- C LU (N
(N
C U) (D C) LO CO qzT ,-
LO
N- (N
U)
(N CO
CO
(N
CO
(N LO
C) C) (N
U) - '(N
C — N '- - C '- '- '- - — — C C (N CO (N
(N
C) (N
U) (N (N U) CO C— CO CO
N-
(N CO
(N -
CO T N- co LU (N U) C N(N NCO N- LO - v- (N
-(NU)
C)
'-(N U)U)(N - CO C
U) C C C C
(N CO U) C) U) .- U) CO U) (N N- (N U) LU N- C LiD LO (N U) N- CO U) U) (N (N .CO LU
C) U) LU U) N U)
N- -
C C C C C C C C C C 0 C C C C C 0 C U) '- CO U) - CO Li) (N CO (N '- (N CO CO (0
N-
-
C '-
CO LO (N IT It
CU) - - CN- C U)C M N- LU 0 LU(N (NCLUC)N-U)COLUN-LU (N (NU)N- N, C U)' U) C C) C C) (N (o (N (N U) -(N N- U) - (N CO (N - (N (N NT CO LU (N LL')'-
U) C U)
U)CO (N
(N
C CO
(0
N- U) U) C) N- C) C) (N .- (N
C C -'-
C
U) N- C CO C U) co C) (N N- C) U)
C
N- C) C (0 (N U) (N CO C) N- CO (N (N LC) (.
CO N-
LO
(N C (N (N '-CO
CCC co (N
C C LU LO LU LU LU LO LO C LU LU LU C LU LU LU C LU LU C U) C .- N- C CO LO N. C CO (0 LU (N (N CO C) U) N- LU 00 cy) 00 co co co
_c--
(0
-
U) C)
r O
EE
U)
N-
C '-
_0 C
(N
- -
C')
CC
CC
CC
-
E (C
CC
CC
-
>'
-c
(N (N (N
(N CO
CC co CL
LU (0 N U) C) C (N .- .- - '- ,-
-
C C C C C C C C C C C C C C C C C C C C C C C C C C C C (C C C C C C C C (N C C C C C C C C U)U) (N (N U) N- U) N- (N - N- C (C C) C U) (N LU N- U) CO CO LU - (N (N U) - (N .- (N .-
(N (N CO
E CC >-(C CM •Fz -o 0 -
LO
114
•
,- IC) (00 (0 C)
(0C) '— (0 N CO
CO CO
00 (0(0 r r
C C'4 C4 .— (0 CO C'J
Ooa
0 CO
0 0 C,-) 0 0I
Z 0 CO C)
C) 0(0 C) 00000(00
0 C"J 0 C) C'J 0 0 (0 0 C) C'J N 0 (0 0 (0 CO CO LO 0 (0 0 N (0 (0 C'.J CJ N (0 CJ 0 C) (0 C) C'J N CO (0
d do
CO
CO
("4
- (0(0(000 (0 C'J (0 CJ 0 N •- CJ CO 0 C) • CO 11, N
0(0(00
ddd (-.4 LO
C) C) C) (-'4(00 — C\J - - (0(0 CO C)N CJ '— '-(-'4 LO C)(0N-C) ,-C)00000C'4 N 0 0 (-'4 .— 00 00 LO N N LO ("4 N CO 0 C\J IT'— ("4 CO - N- 0
CO CO (-'4
- (-'4 LO LO N .
(0 C) — (0 LO
0 CO (N
C)
IN 0 0
-
r
(0
("4
N (0 CO N LO CO LU (-'4 ('4 '— ('.4 - — — ('4 v-
N- ('.4 ('4 ('4 (-'4 0 CO
0
('4
CO -
(0 ('4 CO
q C N-
LU
co
C)
(0
1—
C)
0 N
C -
CO
(0 C (0 LU(0(0 (N '0 r,- CO
T CO
r
(N C)
CO CO
("4
N
LU LU LU LU (0
,--LU'-CON ('4 (0 ('4 (0 CO (N CO LU (0 LU LU N-CO C LU
0
00
(0 (0 N- (0 (0 N- (0 (0 (0 (0 (0
'—
N — ' 0 0 '
N N
(N CO
(0 ("4
(0
— CC 'C
N- CO C) 0 .- ("4
C • '-
EHE
)
° a ca
= C -
E E0 Cacaa)a) -(I) Cd, Q. a) a)
C)
•-
c
CO
E -
E
LU
CC CC (C(3)
- - CCSO a)
C '— ("4
0 c co WO -
N
(0 LO (0 CO IT IT (N("4 ("4 CO CO CO CO CO CO CO CO CO CO'
) — CC '— a) — r
- - (C
'C 0 E.— c oCL
c
(0 ('4 ('4 0 CO (0 C)00 CO N— CO CO ('4 — — ('4 00
0000000000000q 000 C'4 (0(000 (-'4 0(0(0 ("4(0(0 (-'4(0 (-'4 r' r ,- CO ,— r ''
co N ('4
(0
(0 C'4 (0(0 co
CO ,— (0
CO
N-
-CO CO (0
('4
CO
— ('4 —
('.4(00N-(NCOC)0(0h(P (0 ' 0 (N C) CO (N CO 'LU '— ('4 COO -
N-
C)
C ('4 N 0 CO C) NM CO ) (0 ('4 IZT (0 Ln LU(00(0LUN("4C0C'4LO (0 (0 C'4 f C) .— (0 ('1 ("4 (-'4 CO C) '— N ('4 IC) '— 0 (N (
(-'4
0
C4
(0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 C) 0 0 0 0 0 0 0 0 0 C\j 0 N- C) 0 0 (0 '— N N ("4 0 0 CO CO CO .- LU 0 0 ('4 0 '— (0 LU (N (0 (0 0 (N (N ("4
(0 (0 co (0 co
0aD - ('4
CL N-
0
>'
0 0 0 0 0 0 E LU (N 0 ui
-
LU
("4 (-'4
CC (CCC CC
:0 o ol- 0 < °--' o- E o CC (C CC (C 0 LO
(I)
liE
2000
1500
1000 a uJ
0(I-)
LI)
a 500
0
2
4 °/.
6
8
10
12
14
PERMISSIBLE ERROR
FIG.5.1. PERCENTAGE PERMISSIBLE ERROR (CHEMICAL ANALYSIS OF WATER)
5.3 OBSERVATION NETWORK Groundwater quality is also controlled by meteorological factor such as evaporation, rainfall, etc. Therefore it needs a constant monitoring of chemical parameter season-wise. For any regional hydrochemical studies, a set of observation wells are to be selected and sampling have to be done periodically. At least two water samples lare to be collected per calender year, i.e. pre monsoon and post monsoon.
In the present study, 45 observation wells have been established and formed an observation net work.
5.4 SAMPLING AND ANALYSIS Groundwater samples from 45 wells have been collected and analysed using the method prescribed by Palmquist (1973).
5.5 METHOD OF PRESENTATION OF ANALYSIS Two different methods - the ppm (parts per million / mg/I) concentration or epm (equivalent per million / meq/l) are widely used, for the presentation of water chemistry data.
The results of chemical analysis has been listed in Table 5.1. During interpretation, due allowance has to be given for permissible error (Fig. 5.1). The error in the data may be due to the following reasons: human error (analyst), the reagents employed, presence of impurities or in the distilled water and limitation of the methods.
A complete analysis of every sample should be made to verify that the total weight of cations approximate the total weight of anions and in turn these weights are equal to that of the weight of the evaporated residue (total dissolved solids).
5.6 METHOD OF INTERPRETATION 5.6.1 Hydrochemical parameters evaluation by computer techniques
Numerous computer techniques and programs have been developed so far by Ball and Jenne (1979), Niel Plummer et al. (1984), Parkhurst et al. (1990), for modelling thermodynamic speciation of inorganic ions and complex species in solution for a given water analysis and for performing geochemical calculations pertaining to groundwaters. Howeve for routine hydrogeochemical data analysis anc interpretations )conventional methods of classifications are adopted through graphical plot and procedures. Karanjac and Braticevic (1987) have developed an nteractive software for creating a groundwater quality data base and using the same for plotting over Stiff, Piper and Wilcox diagrams simultaneously. Interpretation and facies classifications could be done manually after obtaining the outcut. This application software needs an IBM PC/XT/AT with a minimum of 512 KB RAM. a numerical co-processor, and a graphic printer or plotter. Balasubramanian (1986) has developed a computer program for hydrochemical analysis of groundwaters in FORTRAN-IV. Such classification schemes, if prccrammed in a popular computer language with simple steps, could be employed in almost all governmental private and educational institutions as well. Hence, a simple computer program "HYCH" - in BASIC language is presented here by which hydrogeochemical classification and quality assessments can be done at a faster rate, without resorting to tedious graphical procedures.
4 U,
4 I4 0 3z
cr
Lu
300 w U) (I)
I I.-
oa
Lu°
3-
0L)I
I-
z lx
0(
ILI)
LI) >-I
4 z 4 a-a cr
OW
Lu 0
a] z
Lii LI
Lu 0
ill r -i
JH
Ln
J
IIcI
LU
LI) 11)
U, LI,
LI
Lfl 0 I
lx Lu aa-
LI
LuI
IIIIDI tXIIjI 'ON.JI HCO.
Non-carbonate hardness
HCO3-
< Na--K
HCO.
Non-carbonate hardness
Bi
HCO3-
y Na±K
< HCO
Carbonate hardness
B2
HCO3-
.( Na+K
< HCO-
Carbonate hardness
B3
HCO3-
Na-rK
' HCO
Carbonate hardness
HCO3-
Na±K
A2
HCO3-
A3
Al
)
TSC or TSA (epm)
Salinity
< 2.5
Cl
Low
02
Low
03
Medium -
C4
High
C5
Extremely high
- -
Medium
2.5-7.5
High
7.5-22.5
Very high
22.5-37.5 > 37.5 Sodium hazard (%)
Type
S2
Low sodium water Medium sodium water - Low
0.0-30.0 30.0-57.5
S3
Medium -
57.5-100.0
Si
High sodium water
I 5.6.5 Groundwater type Schoeller has pointed out that the first and foremost water is the one in which rCO3 rSO 4 - Typed as the concentration increases, the above relation changes to rSO 4 >rC l - Type-11. Still at higher concentrations the water may change to rOb rSO 4 > rCO 3 - Type-Ill
and in the final stage rCl>rSO4>rCO3 and rNa rMg rCa Type-IV.
where r represents the epm concentration of ions. The groundwater types prevailing in this area are shown in Fig. 5.14. The prominent type of water is of Type-1, followed by Type-IV and Type-Ill.
5.6.6 Corrossivity ratio Corrosion is a phenomenon of interaction of the material with the water resulting in deterioration. In water distribution system, corrosion causes significant loses in the hydraulic carrying capacity of pipes and fittings when poorer quality of water is being transported.
I This property could be calculated using the formula 2/SO4(mg/f) CI (Mg/1) 96 355 + Corrosivity Ratio HCO3(mglf) + 3 =2( 100 )
5.2
From the computed value,a map (Fig. 5.15) has been prepared. It is seen that area can be divided into three zones, i.e. ii) 2 to 5;
and
iii) > 5
Groundwater having corrossivity ratio (CR) less than 1 is safe and noncorrosive (Rengarajan and Balasubramanian, 1990). In the study area most of the zone falls in the range of 2 to 5. Zones around Perunali (Loc. No.31), Sayaikudi (Loc. No.43), Valinokkam (Loc. No.44), Bogalur, Tirupulani, Uppur and Tirupatakudi (Loc. NOS-21, 30, 8 and ii) are found to be having a
CR higher than 5. Generally the CR more than 2 is
suggestive of corrosiveness. Zones around Tiruvadanai (Loc. No.4). Solandur (Loc. No.10), Kamudi (Loc. No.20). Peraiyur (Loc. No.22), Mudukulathur (Loc. No.23), Sikkal (Loc. No.40) and eastern position of Rameswaram Island are found to have a CR value less than 2. 5.6.7 Calcium carbonate saturation index Figure 5.16 shows the CaCO 3 saturation indices of groundwaters of Ramanathapuram District. The coastal district has been divided into positive and negative zones. Mostly they are over saturated.
146
Stuyfzand (1989) also explained the significance of this parameter. When the saturation index is equal to zero then that water is in equilibrium with CaCO3. When the saturation lndex'O then the water is over saturated with CaCO3. Table 5.7 Stuyfzand's water types based on saturation index Saturation Index = 0 > 0 < 0
Water characteristics in equilibrium with CaCO3 over saturated with CaCO3 under saturated with CaCO3
She also suggested the suitability of this method for application to solutions of higher concentration.
5.6.8 Indices of Base Exchange
Groundwater changes its quality from the point of its entry into the aquifer to point of discharge. For a better understanding a thorough knowledge of its chemical composition during its movement in the ground is essential. Schoeller (1965 & 67) proposed two indices which throw light on this phenomena. There are some substances in the ground which can absorb and exchange their Cations with the cations present in water. Clay minerals such as Kaolinite, illite, exchange in low capacity because the ions are held at the edges. Whereas in the case of montmorillonite and vermiculite, substitution can take place within the mesh and the exchange capacity is high.
The indices of base exchange of groundwaterS of Ramanathapuram District are given in Fig. 5.17.
2
2
I
2
I
2
'.
ii
2
2
I
9
-
2
(wdd) SaflOS C3A1OSSIO 1''1O1
2
-:
°
(wdd) sanos 03A1OSSO 11O1
9
U -y-
cx
z 0
= U LL)
z
If)
If)
8
z
LD z -J -3 0 It
w
ILl I U
>c
w
z
If-)
0L)
+ cr
co o 0
.4
C)
C)
0
0
ILD
C-,'
30
9
0
U,
c iz
147
148
5.7 MECHANISM CONTROLLING GROUNDWATER CHEMISTRY Some of the mechanisms that control the chemical composition of the major dissolved salts of the groundwater have been discussed earlier by Conway (1942), Gorham (1961), Mackenzie and Garrels (1965, 66), Gibbs (1970) and Ramesem and Barua (1973).
5.7.1 Gibb's plot Gibbs (Op. cit.) has suggested a graphical method, by which the possible mechanism can be identified (Fig. 5.18). The TDS is plotted with respect to the ratio (Na+K)
I (Na+K+Ca) and
TDS versus Cl / (Cl + H 00 3 ). In both the cases Gibbs suggested only two zones. i.e. evaporation dominance and precipitation dominance. Depending on the distribution of points the possible mechanism can be identified. Viswanathaiah et. al., (1978) further suggested one more zone in the same diagram in the middle i.e. a zone, of rock dominance. In finding outthemechafliSm that controls the groundwater chemistry of Karaikudi environs,thiS method was adopted by Sastri and Lawrence (1988) and observed that rock type dominance is followed by the Chemistry of percolating water and the rate of evaporation. 5.7.2 Reconstructed Diamond field Piper's (Op. cit.) classification is universally accepted for hydrochemical studies. His diamond field has been divided into six different zones of groundwater which indicate the possible and significant environment. This diamond field was reconstructed by Subramanian (1994) into a single graphical
149
FIg. 5.19 CLASSIFICATION OF HYDROCHEMICAL FACIES AND ENVIRONMENTS (RECONSTRUCTED DIAMOND FIELD OF PIPER) Cci -I- Mg 100
90
80
70
60
50
40
30
20
10 100 90
EIIJ
80
70
60!
40
0 U +50
50& +
0 U
U
40
30
80
20
90
iro
10
20
30
40
50
60
70
80
90
Na+K
INDEX Water contaminated with Gypsum
Sea water
Recent Dolomitic waters
Recent Recharge water.
0 Sample number
100
150
form to represent the percentage of water chemistry data. This modification avoids the plotting of anions and cations over two triangular fields. Simultaneously the facies and significant environments of the groundwater zone are obtained. The water chemistry data of Ramanathapuram district has been plotted on this diagram and the mechanism controlling the chemistry of groundwater has been identified with facies (Fig. 5.19).
It can be clearly visualised that groundwater is contaminated with gypsum . Some of the samples fall in three other environments indicating interaction with aquifer and molecular dispersion from sea waters
5.7 3 Hydrochemical fades
The concept of hydrochemical facies has been attempted by many hydrochemiSts including Morgan and Winner (1962), Back and Hanshaw et. al., (1965), Back (1966), Davies and Dewiest (1970) and Walton (1970).
The term "Hydrochemical Facies" was used by Chebotarev (Op. cit.) to indicate concentration of dissolved solids. He has divided the salinity into low salinity fades, transitional salinity facies and high salinity facies. Back (Op. cit.) further subdivided them to represent various facies. It has been listed in Table 5.8.
151 Fig.
The hierarchical structure of the classification system, with four levels of subdivision.
lubE).
H
C1
"p.
II
Typ.
)t
•IkOIfl,.t,
:c :,,-- ^iA R
;.
.
27
"
Iv CL...
3
1'] '
°a&rL type
Moist type
15
brackish
3
300-10
brackish-sait
b
10 1-104
salt hypnrhoilrso
S
1Q'-2.1O
very o11çohailne S q
5-30
Orh-br.cki q h
F r
30-ISO 150-300
•Lko)ivtty
nor.
Cod. Cl PH/L
Code Cl o/I.
oitcohal.ine
Cadn
H
type
•IL.lInity cod,
fre1Ll
Lou
-1 0 low
Ins.s.iy low
1
2 s,cl 10e
-
1
0
I -
2 4
2
3 -
3 ,.wdsr,t,ly 0170
I -
4
4 hl q h
I -
Ii
5°'y 0420 6 en0tjy CLsh
1
(.41./Il. (I
7 Ly hIfl 8 s'.trs'.ly hi-rh
16-
32
6
32 -
64
4
'4 -
38
7
123 -
356
3
4
26
9
3 9 e-re-ely 4
0170
)
'.(I • ((1(1 • 1.5) I
9
Al•
/C7
SO, NO3
//\ IIIA U MV
hj
C.''
Cl
f
Subdivision of types into subtypes on the basis cf the proportional share of main constituents in the swo cf the cations (left) and anions (right), both in nseq/L. Cc-.).
Ci...
fl.t I
5.20
. .
.
,
•
S
•
I1l)d.(ICII 4 - Ii), .,jwlIi).,I. . 2 • ,,&,.
alien LtdIcatL.. 0(
01 4
I 5 4 '' . 4 Iv., I • - 1 9
Condition. (or I 04 . 0 . Pql cor,.ctrd l..-,IL) .nd 'iCl - l.liCl...d , .o.J /4c1 .
I ......haIC,tB.
"IC! on.) $1 (kiln - Lot
•
Ian I.ny.n.r.. .nytI.*l
'Lb-IA'
I
1.1114
B
IS)
.44(n.c.r i,,tIu.IOfl any t.,s,.n.,.. r1.4 1 I .....I sq .4th n.c.r 01 00414(1.1 CP0. 4(4041
. ' o(t.n in..ic.. ln,oc.4s..n.1., In,...
84 •
4
4
--
/iCk ) s I.!
3.-to)
(After Stuzand, 1989)
152
Table 5.8 Classification of Hydrochemical Fades (After Back, Op. cit.). Percentage of constituents Fades
Cation Fades Calcium-Magnesium Calcium-Sodium Sodium-Calcium Sodium-Potassium Anion Fades Bicarbonate Bicarbonate-Chloride Chloride-Sulphate- Bicarbona te Chloride-Sulphate
Ca+Mg
90-100 50-90 10-90 0 -10
-- -- -- --
Na+K HCO3+CO3 Cl+SO4
00 P2 < P3).
This type of sounding curves
are obtained in hard rock terrain consisting of a dry top soil of high resistivity, as first layer, water saturated weathered layer of low resistivity as second layer and compact hard rock as third layer.
'A'-type curves are obtained only when a hard rock has a conductive top soil. In such cases, resistivities of all layers will be continuously increasing (P 1 < P2 < P3). When the middle layer has a higher resistivity than the other two ) then the resulting curve would be of 'K'-type (°i < P2 > p3).
'Q'-type curves are obtained where a continuously decreasing resistivity > P2 > p 3) exist, especially in coastal aquifers with saline water. In the study area , the
types of VES curves
obtained are K, 0
and H types. 0 type curves are obtained very nearer to the coast line, indicating the aquifer saturation with clayey beds and saline water. In a few locations, the
173
Table 6.3 Available computer inversion techniques for resistivity data interpretation
Technique
Sources
Year
Mooney et at
1966
Resistivity Computation for earth model
Meninardus, H.R
1970
Numerical interpretation for resistivity sounding.
Das, U.C. and Ghosh D.P.
1974
Determination of filter coefficients for computation of standard curves.
Sri nivas
1975
Direct interpretation of geoelectric measurements.
O'Neil D.J.
1975
Linear coefficient application in apparent resistivity computation. Automatic solution for inverse resistivity problem.
Sri nivas, Pawan Kumar 1982 and H.R. Wasan Zhody,A.A.R.
1989
Automatic interpretation of Schlumberger and Wenner method.
Basokur, A.T.
1990
Computer program for direct interpretation of resistivity.
Raghu, K. Chandru, R. Nagendra and N.S. Patangay
1991
FORTRAN program for computing apparent resistivity
Steven D. Sheriff
1992
Modeling of Electrical sounding using convolution and spread sheet.
presence of K type indicate a hard and compact sandstone and shell limestone along the coastal zone. Presence of H type in some locality is the indication of highly resistive top soil and a saturated aquifer zone with a resistive substratum.
Automated Fit of VES data: Quite a large number of computer techniques are available in order to interpret the field VIES data and a few of them have been listed in Table 6.3.
To minimize the possible error in manual curve matching, computer inversion procedures are widely used. The following are the normal input data requirements in these interpretations;
(i) The number of layers (ii) electrode configuration (iii) an assumed model layer resistivities and thickness and (iv) the field spacings with their apparent resistivities.
The program developed by Vander Velpan (1988) has been used in this work for VIES data processing. This is an iterative procedure. Instead of assigning guessed model parameters, the parameters derived through manual curve matching have been made use of to obtain the best fit results. The computed Pa value has been compared at each iteration with the observed field values and by iterative method, convergence is obtained to a minimum level. 'When the error between the computed and observed value is less, the resultant model is produced as output.
175
5--- ----S-
SS
S
S
.5. .5.'..
.
I- lI -
I
( ) 1PI( ii1;i-I]
ICURRENT: SPARKONIX (INDIA) PUNE.18
PL.40,6, CRM - 500 PANEL BOARD VIEW.
:
i.
176 EEIII]
E
1I-
If)
Ln w crIz w
Ir aa--
LL!J
A13/2 Fig. 63a. GEOELECTRIC SOUNDING CURVES OBTAINED IN RAMANATHAPURAM DISTRICT.
177 EC
E
> 1=
V)
10
Ln
w cr z
No]
E
> (JU 10 LU z
Lu
cx
a-
1
1
10
100
AB /2 Fig. 6.3b GEOELECTRIC SOUNDING CURVES OBTAINED IN RAMANATHAPURAM DISTRICT.
300
100
E
cr cr
10
1
10
100
AB/2
Flg.6.3c. GEOELECTRIC SOUNDING CURVES OBTAINED IN RAMANATHAPURAM DISTRICT.
:179 ms
E
10 Iz ILl
0.
E >> w Ir
z w cr CL
10
'vu
AB /2
Fig. 6.3d. GEOELECTRIC SOUNDING CURVES OBTAINED IN RAMANATHAPURAM
DISTRICT.
180
.nn ODE
E
> p
w z
w
10
cr
10
1(X)
AB/ 2
Fig. 6.3. GECELECTRIC SOUNDING CURVES OBTAINED IN RAMANATHAPURAM DISTRICT.
18]. 100
E
it > 'I,
U cr z U cc
10
4
ml
E
> I10 z
Lu
1
10 AB/2
100
Fig. 631. GEOELECTRIC SOUNDING CURVES OBTAINED IN RAMANANATHAPURAM DISTRICT.
1
100
E
10 uj LLI
CL
1
10
Iuu
AB /2 Fig.6.3g.GEOELECTRIC SOUNDING CURVES OBTAINED IN RAMANATHAPURAM DISTRICT.
18
500 400 300
_ 100 E
> p.LI) LU ir z LU
aiIiJ
1
10
100
AB/2 Fig. 6.3h. GEOELECTRIC SOUNDING CURVES OBTAINED IN RAMANATHAPURAM DISTRICT.
184
Table 6.4 Layerwise geoelectric parameters of the 'aquifer in Rarnanathapuram District Resistivity (Qm).
Thickness (m)
S.No hi
h2
h3
P1
1.9 3.1 2.4 2.2 2 2.6 4.8 3 1.4 19.5 1.9 4 0.9 16.4 5.5 5 1.1 1.8 6 1.8 59.8 12.5 1.0 7 5.8 11.5 2.0 8 4.3 6.5 51.8 5.3 2.4 9 1.7 7.3 1 iJ 1.3 33.1 10.7 0.9 11 4.7 14.1 3.0 12 9.1 29.4 3.2 1.9 13 4.7 5.7 1.6 14 51.4 4.2 5.8 8.3 15 1.5 2.4 16 6.3 54.6 7.4 1.2 17 26.7 5.6 18 2.7 32.9 19 9.1 6.2 20 3.5 29.9 1.4 21 4.3 13.9 4.4 22 6.8 14.0 2.2 23 10.9 44.4 4.9 24 8.7 28.4 4.3 25 5.1 68.3 42.6 7.2 2.5 26 0.3 23.9 8.9 27 99.9 17.5 11.2 1.8 28 362.7 11.0 13.4 2.1 29 147.2 46.0 6.8 0.8 30
P2
P3
5.4 7.4
6.5 5.8 1.8 2.7 2.3 81.4 8.6 6.8 2.4 7.6
27.7 7.6 28.1 4.2 8.7 78.1 0.2 1.4 1.7 2.2 1.5 1.2 1.6 228.9 0.9 13.0 270.8 276.0
2.7 6.0 1.3
1.2 7.6
3.6
1.2 92.6
3.6
6.4
193.0
98.6 24.0
271.0
3.4
17.8
6.0 1.0 2.0 12.4 9.6
0.01 4.5 16.4 1.4
0.3 0.7 0.8 0.1
18
District. Aquifer geoelectrio properties from Ramnathapmw S. No. Location Name. Transverse Long i tud ma I. Thick- Aquifer anisotropy ness resistance conductance (?) (li)(m) (S) mhos (t).c.in2
Table 6.5
1 .Oriyur 2. Ti ruvegampattu 3. MuppaiyUr 4. T i rimkiana i 5.Thondi
6.R.S. Mangalan' 7 .Uppur
8 .ParthibaflUr 9.Nainarkoi I 10 .Paramkiidi ii.Devipattanam
12.Pallirnittai 13.Abi ramm 14.Kamud i 15.M.P.Salai 16 .l3ogalur 17 .MudukulathUr
18.Han.nathaPul' 19.U. KosMnanga i
20.Va I anthara.Va 21 .Perunal I
I
22 .Tirupptllafli 23.Sikk&1
24.Kflakkarai 25 .ErVa%I1 26. Saya I kud i
28. MandaPWfl Camp 29 .0aikxXIa (1aneswaram) 30. Pudu 'Road
(Tb3mesram)
1.931
56.22 4.77 0.73
3.1 2.2 4.8 21.4 21.9 1.8 73.3 13.5 59.5 7.3 4-4.7 17.1 34.5 7.3 18.3 2.4 63.2 5.6 32.9 6.2 31.3 18.3 16.2 49.3 32.7 52.3 32.8 30.5 26.5
2.163 5.042 4.893 1.326 8.824 5.804 7.875 2.708 6.953 6.022 6.461 3.816 4.343 1.549 8.346 2.310 5.738 2.487 5.656 4.444 4.612 12.674 6.786 4.255 6.437 7.945 ii . 220
32.89
53.6
35.544
1.79
6.46 5.28 12.48 115.76 34.50 1.98 102.36 947.70 283.90 12.41 66.50 248-10 294.00 265.80 690.40 3.60 267-50 149.50 88.80 56.40 55.70 49.50 35.90 106 .70 82.80 2036.09 24.18 403.67 4570.80
15.12 1.60 55.80 0.48 13.00 4.30 32.50 2.50 4.90 0.40 0.50 1.60 17.10 0.20 12.20 0.88 17.98 7.30 9.60 74.40 18.20
2058.96
0.91 1.80 4.70
8.42
1.478
186 771001
78130
Pudukotlai Dt
Fig.6.4 RAMANATHAPURAM DISTRICT AQUIFER ISORESISTIVITY ONTOURS(Ist layer)
2
0
N
3.1.
P.M.T Dt.
INDEX
6
Kamarajar Dt.
80
9
Q
•
10
11
Palk bay
1
T1
16
VES Location Iso/Resitivity /10 Contour (fl..m)
17
10 2
21
(D23 25 27
100
20
22 0
28
29 3)
214 Gulf of manaar
Chidrnbarq -nar Ot. Pudukottai DI.
Fig. 6.5 RAMANATHAPURAM DISTRICT AQUIFER ISORESISTIVITY (2nd layer) CONTOURS
N
23 D
5 INDEX
P.M.T Dt. 6 7 0 ® 0 8
Kamorajar ot. .12 15
2 0
Polk bay
®9
0
11
'10
13 0
YES Location
/Is o10 Resilivity ( Contour (flm)
1 /
')16
4c 17 0
20
9 23
21 0
25
24
29
022
28
Gulf of manaar
27
Chidambara - nor Dt.
0
o s io KM 79 * [DO
c
187
Pudukottal Dt.
Fig. 6.6 RAMANATHARJRAM DISTRICT AQUIFER ISORESISTIVITY
N Ljj
10
CONTOUR (3rd Layer)
()
3
9
INDEX P.M.T Dt. 0
0
T
Kcimarujar
/1S0
0
Dt.
VIES Location
1
Resistivity Contour ( ..nm)
Pof< boy
.12
1000
09
Path bay
® VES
Location
o
®13
1•.2
1 •
•29
28
2
9•I
2
3
9. 15
25
Gull of manaar
27
—26
L21j
Chi dambar -narD
Pudukottai Dt.
Fig. 6.13 RAMANATHAPURAM DISTRI AQUIFER UNIT SPECIFIC 0 C ONDUCTANCE (5)
N [1No1
I5
S in mhos units io fffl
P.M.T DI. Kamarajar
ot.
>10
0 09
.2
VES
Location
Polk boy
135
\0
.1
17 0
2
(D19
28
29 30
15
Q
9.
._501inohm-rn2 . units LItllJfl71 ( MP t (9P'Wl) 2520 SL 2c30 RETU'N
257
APPENDIX 5 WIDTH LPRINT 65 1000 REM X************************************************1** * BASIC COMPUTER HYCH 1010 REM * * 1020 REM * PROGRAM FOR HYDROGEOCHEMICAL FACIES DETECTION * AND INTERPRETATION OF WATER 1030 REM * * QUALITY PARAMETERS 1040 REM * * T. F LAWRENCE 1050 REM * 1060 REM 1070 DIM kRRAYS(10),F.(l0),NN(IO),SS(l010,CL.\SS$(20) 1080 DIM A$(6),C$(5),SS(5),TS(3),CF(l0),P.iO), CD(iO),FF(10)BD(IO 1090 DIM F1(10)F2(i.0),HP(lO), EW(10),B$(10) ,RF.S$(10) 1100 DATA AIK-VERY LOW,ALK-LOW,ALK-MODERATET.Y LOW, A[.K-HODERATF.,AL K-MOD-HIGH ALK-HIGH, ALK-VF.R''-HIGH ALK-EXTREHELY HIGH ALX-EXT-HIGH A1,K-EXTr1--HIGH, ALK-EXT-HTGH 1110 FOR LI TO II :RFAD C1.ASS(L):NEXT L 0, I II20 DATA AI,A2,A3,B1,B2,B3,C1,C2,C3,C4,C5,S1,S2,S3S4,55, 11,111, TV 1130 DATA 20.04,12. 5252,23,61 .02,30.001 35.453,62,48.03 1140 DATA 40.08,24.32,23,61.02,60.01,35.45 7 ,62 .01 ,96.07,2,2,1,1,2 1,1,2 1150 DATA .5399508,_.124333,-7.752454E03,2.367353F.-03,4.477692E _04,_3.728097E_05,-1.388233E-05,8.311549E07,3,6,4,0,0,3,1,2,O,2 5 , 7 5 22. 5 , 25 160 DATA 8.484292E_02,_8.354048E-02,2.505801E-02,7.745833E-03,1. I 72073E-03 , -9. 5Ol622E-05 -4 .9511 32E-05 . -3. 706292E-06 1170 DATA 7.943,6.31 5.012,3.981 3. l62,2.512, 1,995,1.585,1 .259,1. 0 1180 DATA ,8 ,8 1190 DATA 4,4,4,4,4,5,5,5,7.7,4,4,4,4,5,5,5,6,7,7,4,4,4,5,5,5,6,6 '7,7 1200 DATA 3,3,5,5,5,6,6,6,7,7,3,3,5,56,6),6,6,7,7,1,i,2,2,2,2,2,2 6,6 1210 DATA 1,1,2,2,2,2,2,2,6.6 1220 DATA RECENT RECHARGE 'ATF.R "TON EXCHANGE, RECENT DOT.OMTTI AND H C WATERS' , 'STATIC AND DISCO-')RDTNATED REGIMES ,"DISSC1.UTTON TXTNG" , 'DYNAMIC AND CO-ORDINATF.D REGIMES -WATER" 'WATERS (TON 1230 DATA "CONCENTRATION & PRECIPITATION lAMINATED WITH GYPSUM' 1240 FOR .J=l TO 6:READ A.$(J: 14EXT ,J:FOR K1 TO 5:REAI) C$(K):NEXT K 1250 FOR .J=l TO 5; READ S$Lfl:NEXT J: FOR K1 TO 5: READ T$(K):NEXT K 1260 FOR .J1 TO 8:READ CF(J):NEXT ,J:FOR K1 TO 8:READ CD(K):NEXT K 1270 FOR .J = 1 TO 8:READ FFTJ):NEXT J:FOR K1 TO 8:READ Fl(X):NEX T 1280 FOR .1 = 0 TO 7:READ NN(.J):NEXT .J:FOR K1 TO 5:READ NP(K):NEX T 1290 FOR .1=1 TO R:READ F2(,fl: 14EXT .J:FOR KI TO 10:READ HP(K):NEXT K 1300 FOR T1 TO 10:FOR J1 TO 10:READ SS(I,,J):FXT J:NEXT I 1310 FOR 1=1 TO9:READRF.SS(I):LPRtNTRES$(T)MFXT T:LPRINT DEFINITION OF VARIABLES: 1320 REM INPUT DATk SECTION PH=pH: 1330 REM NA$1D,CODE; EC=ELEC.CONDUCT(rnmhOs); 1-Ca 2-49 3-aK 4-8CO3 5-0O3 6-Cl 340 REM ARRAY E : 7-NO3 8-SO4 1350 RFM 1360 REM TDS(lpm) ; TTemp(drg.crnt); GOP & DO as measured. I TO 8:READ E(j):F(,r)=F(,1):NFXT J:RF.A 1370 READ 4AS,EC,PH:FOR ,T D T0S:T25;ORF"0:D00
258
1380 INPUT 'Press Enter hey ' ;OO:GOSUB 3130 1390 LPRTNT SAMPLE CODE";NA$:GOSUB 3130 =";TDS 1400 LPRrNT "EC(mmhos) =";EC"TDS (ppm) ";ORP =";PH,"ORP 1410 1.PRTNT "pH =";DO,"Temp.(CefltIS) =";T 1420 1..PRTNT "DO 1 , 130 IF TDS=0 THEN TDSEC*,64 1440 AC.001 :SS=0! 1450 FOR .Jl TO 8; IF P(J) = 0 THEN P(.J)r-1E08 1460 EW(J)P(J)AC/CD(j)':T,PR1N T USING" =SS+EW(J)*FF(j)2tEXT .1: LPRTNT 1470 SSSS+EW(T)*FF(j)2NEXT J:1,PRTNT 1480 1S=.5*SS;SS=1_0G(SS)Y1 =F3 (I) :Y2F2( 1490 FOR TC2 TO 8:Yl=YI+Fl(IC)*(5S(TC_)222(T*S(TC_ l) ):NEXT IC 1.LPRTNT BH,RCA 1500 RHYI:RC Y2:IXINT((PHF lX2=PP 1510 3520 IF PP=0 THEN 1X2=10 1530 FC=HP(IX2)*(10(-TX)) 1540 1550 Al=_LOG(EW(1))/2,303A2=1OE4/2303 3130 1560 PHC=Al+A2+1,9:DPH=PH_PHCHON_DGOS Cl CO3 RCO3 Na+K M Ca 1570 LPRTNT "Conc/Ino SO4" 803 1580 GOSUB 3130 4,#";P(J);: ";:FOR J1 TO 8:LPRTNT USING' 1591) LPRINT ')pm NEXT J:iPRTNT 5);50):FOfl J1 T08:E(J 1600 C8((E(6)/35 ,5)+(E(8)/48))/((F(4) )=E(J)/CF(j):P(j)E(J):NEXT 1 ";:FOR •1=1 TO 8:1,PRTNT USING" ##.#";E(J);: 3610 LPRINT "epm NEXT ,J:LPRINT 1620 CA=E(1)MG=E(2)NAh=E(3)3=E(4)CO35)6)3E(7) SO4E(8) 3630 SUM1O;FORJ = l TO 3:SUH1=SUMI+E(j)T1TSC112316 * TDS TO 8:SUHlSUMl+E(,J)9TT5M101)S( 1640 SUHl0;FORJ TSC-TSA) 1650 IF, TDS > 300 THEN PE = '- ,01*TDS 1660 IF TDS >200 THEN PE = 5,66667_.00332TPS 1670 IF TDS >500 THEN PE=5- . 002*TPS 1680 IF TDS >1000 THEN PE =4,00l*TDS 1690 IF TON >4000 THEN PF. = 1.5 54,,S=C5.LPRTNT Is 3700 01F2=DT F I /(TSC+TSA)*b00 V=02US ,Lsa'';TSC,TSA 1710 LPRI.NT "%PF. =";PE,ThhserVed" ;DTF2 720 IF DTF2-PE< = 0 THEN 3730 ELSE 1,PRINT "ERROR IN ANALYSTS :STO P 8) E(5. E(4) 6 E(3)) LA2( 1730 Cl,U=(E(6)_E(3))/ B) SAR=E(3)/SQR( (F( 3 )+E(2) )/2) 458 SAR).PT3 1740 PTI=lO 4,97S3_.t344*S)T230 (4,6452 4.I878_.2188*SAR) 1750 IF EC50 THEN ZS=Y$+" 2230 IF 88>80 THEN 7$=V$ 2240 I=INT(E( 4 /10):J=INT(AA/10):IF 1=0 THEN 1=1 2250 IF J=0 TEEN J=1 2260 EN=SS(I,J 2270 13= I0(3!-PH):TK 1(I) +273.15 2280 MU= .0005 '(CL +H(k)3+NO3 +R+NAK--2*(SO4 +CO3+(A+G)) 2290 GAM1 = 10(-.05 S (SQR(MU) /(SQR (MU)+l) - 3 t.ftJ) 2300 SAN = TSA:SKATH/GA11+TSC 2310 SAS = 'G-V.OLTGOHALINE 2320 IF Cl. > .141 THEN SA$= 'g-Oi igohal me 2330 IF CL >9-15 THEN SAS = -F-Fresh 2340 IF CL ) 4.231 THEN SAS = -r-Fresh-brackish" 2350 IF CL 8.462 THEN SAS-B-Brackish 2360 IF CL > 29.206 THEN SAS = "b-Brak i sh-sa t 2370 IF CL > 22.004 THEN SAS = -S-Salt 2380 IF CL >5.I27 THEN SAS = H - Hptrhmtl int' 2390 A[ K= RCC'3CO3:.ALKFT= TNT( LOG (\!.K)'LOG(2)I) 2400 135= CLSSS.ALKFI-2) 56 THE' RS=CLASS$(II) 2410 IF A1.K 5
260
2420 IF ALK < = I THEN B$=CLASS$(2) 2430
IF
ALK = .5 THEN B$=CLASS$(I)
2440 SNO3 NO3:H7 H/GAMt (10 (12.0875 - .01706 * TK - 4470.099/TK))/(H *GAM1) 2450 OHC = 2460 CO3F = CO3- OHC (SKAT/2) THEN 2480 ELSE 2323 2370 IF NAK 2,180 IF NH4 > NAK THEN 2490 ELSE 2500 2490 SI$'NH4 :GOTO 2510 2500 S1$' NA+K 2510 GOTO 2560 2520 IF (CA +MG) > HZ THEN 2530 ELSE 2560 2530
2540 2550 2560 2570 2580 2590
IF
= CA THEN 2540 ELSE 2550
MG
S1$ = Mg': GOTO 2560 Ca S1$ = IF CL > 'SAN/2) THEN 2570 ELSE 2580 S25 = Cl' : GOTO 2670 (SAN/2) THEN 2590 ELSE 2630 IF .\LK
IF
8CO3 > CO3 THEN 2600 ELSE 2610
2600 S25 " HCO3": GOTO 2670 2610 IF CO3F > OHC THEN S2$ = ' CO3" ELSE S2$ =' OH" 2620 GOTO 2670 2630 IF (SO4 + SNO3) > (SAN/2) THEN 2640 ELSE 2660 2640 IF SO4 > S!403 THEN S2$ " SO4 " ELSE S2S'NO3" 2650 GOTO 2670 260 S2$ " Mixed" 2670 SC$= 144K + MG - 1.0716 * CL 2680 NAKMG 2690 IF NAKMG > SQE (.5 * CL ) AN1) NAKHG > (I 5*(SKAT-SAN)) THEN 2710 ELSE 2720 2700 IF NAKHG ) (1.5 * (SKAT 2710 SCS = "(+ Na+M9 SURPLUS GOTO 2780 THE ANYWHERE (- SQO (5 * 2720 IF 14AKHG EN 2740 ELSE 2750 (1.5 * (SKAT 2730 IF NAKMG 2740 SC
"(- Na+Mg
-SAN)) THEN 2710 ELSE 2720 INDICATES FRESHWATER INTRUSION-ANYT CL)) AND NA}(IG
(I.5*(SKAT-SAN)) TH
- SAN)) THEN 2740 ELSE. 2750
DEFICIT
INDTCATE SALT WATER TNTRUSTON.ANYWHE
GOTO 2780 RE-ANYTIME ' 2750 IF SKAT = SAN THEN 2760 ELSE 2770 EQUATE FLUSHING WITH WA 2760 SC$ = '( . ) Na+Mg EQUILIBM IND ICATE T GOTO 2780 TEE OF CONST.COHP " 2770 IF (ABS (NAK}IG +SQR(.5 * CL ) *(SKAT - SAN)/ABS (SKAT -SAN) ABS (1.5 * (SKAT - SAN))) THEN SC$ = "( . ) Na&MS EQFIM INDICATE ELSE SC$ ADEQUATE FLUSHING WITH WATER OF CONST.C3IP 2780 [PRINT 2790 LPRTNT "Sodium Absorption Ralio =';SAR:I.PRINT "Residual Sodi urn Carbonat-e = " RSC ; NCR: [PRINT "Percnab Ii ty 2800 [PRINT "on-arbonate Hardness PPI = Index(Drefl) IS; :LPHINT 2810 [PRINT "TONIC .STRENGTH "USTNG"# CORPOSTVTTY RATIO 2020 LPRINT
"INDICES
OF BASE EXCHANGE =" USING
LA2: [PRINT CaCO3 SATURATION INDICES :" :LPHTNT 'Equil 2830 [PRINT " Equilibrium .IJRTNT AIM mPl)io d=USTNG *. brium Ca ;HYION 4" 4 pH rne1lioJUST" MECHANISM CONTEOILIG THE CHFHTSTDY = 2840 [PRINT "GTRB'S P1.01 NIECHS 2850 DP$="Modertte" ELSE DS='TmtuO THEN D"Ft AVS(I),1). 2860 IF I . EFTS(A rarV 2270 IF RIGHT
ARRAY
2,
=1' TREN Dr.S-'V.L''
261
2880 IF RTGHT$(ARR.AY$(2)1)"2" THEN DD$='Low 2890 IF RTGHT$(ARRAY$(2),I) = "4' THEN DDS="High" 2900 IF RIGHTS (ARRAY$(2)l)"5" THEN DD$="V.High' H\NDA'S CLASSIFICATION :':LPRIN 2910 GOSUB 3130:1PRINT ' DS:LPRINT "Sal i nity =";ARRAY$(l)" I Hardness 00$ 2920 DD$Lo ' ": TF HIGRT$(ARRAY$(3),l) = "2" THEN DD='ModeraL' 2930 IF RTGHT$(ARRAY$(3)1) = "3" THEN DDS ="High" rCa" rMt4 2940 D$' rCl ) rSO4 > rCO3 and rNa I" THEN D$ = "rCO3 > rSO4" 2950 IF ARRAV$(4) 2960 IF ARF1AY$(4)' IT" THEN 9S"rSO4 ' rCl' rSO4 > rCO3" 2970 IF ARRAV$(4)="TTT" THEN D$="rCL .. 3130:1,P ";ARRAY$(3) " 2980 1,PRINT "Sodium hazard ";ARRAV$(A)" HINT "SCRC'EI.LFR'S 'WATER TYPE (r=e.pm)':LPRINT " OS Since PTPF,B'S HYDROGEOCHEMICAL FACES 2990 GOSUB 3130:LP 7ZTNT ";P$,Anions =";ZS :":LPRTNT "Cations ' ;RES$(EN) 3000 LPRTNT SIGNIFICANT ENVIRONMENT STUYFZAND'S CLASSIFICATION:' 3010 GOSUB 3130:LPRINT " 3020 LPRTNT "WATER TYPE(Based on Cl) z ";SA$;LPRINT "SUB-TYPE(Base d on Alk) =";B$ ";Sl$ "" ;S2$ 3030 LPPINT "FACES 3040 IPHINT "SIGNIFICANT ENVIRONMENT : USSI CLASSIFICATION 3050 GOSUB 3130:1,PRINT " " ;SL$, "Sodium hazard =;US$ " 3060 [,PRTNT Salinity 3070 GOSUB 3130 3080 [POINT 3090 INPUT "press enter to continue";OO:CLS 3100 GOTO 1370 3110 STOP 3120 REM TO 70:1,PRINT "-" :NFXT KK;LPRI'T RETURN 3130 FOR KK
262
APPENDIX - C
C C
PROGRAM SUTINPT DEVELOPED BY J.FRANCIS LAWRENCE. DEPT. OF GEOLOGY ALAGAPPA GOVT. COLLEGE, KARAIKUDI (INDIA)
C
C C C C C C C C C C C C C C C C C C C C C C C C C
*
THIS IS A PREPROCESSOR FOR CREATING THE INPUT FILES SECOND.D6 AND SECOND.D55 REQUIRED BY SUTRA WITH LESS NUMBER OF INPUT DETAILS THE PROGRAM READS THE INFORMATIONS ABOUT THE DOMAIN FROM A SMALL FIJ.E VLDAT SPECIFICALLY FOR RAMANATHAPURAM AQUIFER SIMULATION AND NEEDS VERY LITTLE MODIFICATION FOR OTHER DOMAINS
DEFINITION AND SEQUENCE OF VARIABLES FOR V1.DAT TITLEI PROJECT TITLE AND AREA DETAILS NX= NUMBER OF ELEMENTS IN X-DIRECTION NY= NUMBER OF ELEMENTS IN Y-DIRECTION DX,OY , DZ=GRID SPACINGS IN X,Y & Z DIRECTIONS NP INCH, NPBC,NUBC,NSOP,NSOU, NOBS, NTOBS IUNSAT,ISSFLOW,ISSTRA,IREADS T ° RE } AS NEEDED IN SUTRA ) ITMAX, DELT, THAX --DO- ATMAXF HDI UPSTREAM WATER LEVEL TO COMPUTE NODAL PRESSURE HEADS FOLLOWED BY THE SET OF DETAILS AS REQUIRED BY NPBC,NUBC,NSOU, NODS , ETC AN ARRAY OF NODAL TDS/10000 AS INITIAL CONC THIS SEGMENT COULD BE COMPILED IN WATFOR77 IMPLICIT DOUBLE PRECISION (A-H2O-Z) DIMENSION IN(4),IWW(116),TT(45.30),IP(100)(40 DIMENSTON [C(400),HH(400).CC(400)PC(40 0 )T C(45 30) (!00) 100) DIMENSION NN2(100),NN3(100),TQCP(100),Q DIMENSION IQCU(100),QUTNC(100)IPBC(100)PBc(100)100) DIMENSION IUBC(100),UBC2(100),HT(100)Ji100) CH.ARACTER*4 ADSMOD CHARACTED*12 STMULA CHARACTER*10 TITLE! ,TITLE2 OPEN(5 , FIIE= ' V I. DAT' , STATUS = ' OlD SIMULA = SL'TRA SOLUTE ADSMOD NONE' FAD(5,*) TITLE! READ( 5, *) TITIE2 RF\D(5. 5) NX , NY DX , DY,D7 \L=1 VI= NN=NX+I)*(NY+I) NF=( NX*NV) N8I(NY+I+2-I)*2+1 \ [=\1*NX I-=VL SN Y N\=NX+! DE.\fl(5,*) NPTNCH.NPBC,NUBC,NSOP.NS0U,NOBSNTO
263
515
READ(5*) IUNSAT,ISSFLO,ISSTBAIREAD,TSTORE UPO 0 GNUP=1 .OD-OO GNIJU=l .0D-00 NPRINT= I KNODAL= I KELHNT= K INC ID =0 KPLOTP= I KPLOTU 1 KVEL= KBUDG= I ITRHAX= 100 RPMAX = 10. 0 RUMAX = 10,0 COMPFL = 0. 0 CW=0. 0 SIGMAU6 . GE-06 SIGMAS='.0 RHOWO= 1000 URHOWOO .0 DRWDU 700.0 VTSCO I E-03 CONIPMAO .0 CS=0 .0 RHOS=0 .0 Ciii 1=0.0 CHI2=0 .0 PRODFO') . 0 PRODSO =fl .0 PHODF I =ñ. 0 PRODF2=0 .0 GRAVX=0 .0 GRAVY=-!.0 SC A LX = DX SCALY = DY SCALTHDZ POHFAC0. 32 HEAD(5) ITMAX.DELTTMAX DELT0*0*24*30. 5*j 2 READ( 5.*) iTCYC99999 DTHULT=I .0 .0 DT'AX NPCYC I NUCYC I HEAD (5*) HDI DXXIIDI / 14 DYYIIDI +DXX DO 515 [=1.13 DY Y DY Y - DXX HT(T)=DYY DO 7171 T1 13 DO 7171 .1=1 .8 R00*( ( (8-j+I )*IO)HT( I)) TT( I ,,J
264
IF(I. EQ. 13) GOTO 7173 GOTO 7171 7173 TT( I,J)=(9.8*1025)*(((8._J+1)*10)+(HT(I)/2)) 7 1 7 1 CONTINUE 21 12 FORl1AT( 13(F4 .0)) DO 8282 1=1,13 8282 WRITE(* 3344) (TT( I . J) J= I 8) 3344 FORHAT(8( lx , F 10.0)) L PP =0 DO 6761 J=8.8 LPP=LPP+ I IPBC( [pp) =.J PBC(LPP)=TT(1 ,J) UBC( LPP)=0.0 6761 CONTINUE DO 6861 1=2,13
LPP=LPP+ 1 IPBC(LPP)=1*8 PBC( LPP)=TT( 1.8)
UBC ( LPP ) =0. 0 6861 CONTINUE DO 6863 JI .7 LPP=LPP+ I IPBC(LPP)=96+J PBC(LPP)=TT(13.,J) UBC( LPP)=0.035 663 CONTINUE TF(NSOP.EQ.0) GOTO 1191 DO 9111 II=l,NSOP READ(5,*) IQCP(II) ,QINC(II),UINC(i1) WRITE(* 308) IQCP(TI),QINC(II),UINC(II) 9 11 1 CONTINUE 1191 IF(NSOU.EQ.0.0) GOTO 2292 DO 9222 IT=l .NSOU RE.AD(5,*) IQCU(TI) .QUINC(TI) QUINC(II)=0 . OE-00 9222 CONTINUE 2292 IF(NPBC.EQ.0.0) GOTO 3393 DO 9219 II=I,NPRC [) WRITE(* .308) IPBC ii) P8C( II), UBC 9219 CONTINUE 3393 IF(NUBC.EQ.0) GOTO 9888 DO 9444 11=1 ,NUBC READ(5,*) IUBC(II) .FIBC(1T) 9444 CONTINUE 9888 NOBCYC=0 IF( NOBS . EQ. 0) GOTO 9113 DO 9555 II=1,NOBS READ(5,*) IWW(II) 9555 CONTINUE 9113 READ( 5, 8979)( (TC( r . J) , .1=!, 8) 1=1. 13) 8979)( (TC( 1. J) J=I, 8), 11. 13) 979 FORM;T( SF3.0) 8969 FORMAT( 7F3 . 0) WRITE(*.*) ITRiAX.RPMAX,RUMAX
265
143 144 142 141 139 138 137 136 135 134 133 132 131 55
WRITE(*,*) SCALX ,SCALY, SCALTH, PORFAC OPEN(7.FILE = SECOND.D5' ,STATUS='UNKNOWN') WRITE(7.55) SIMULA URITE(7, 131) TILTEI TITLE2 WRITE(7,132) NNNE,NBI,NPINCH.NPBC,NUBC,NSOP,NSOU,NOBSNTOPS R1TE(7.133) IUNSAT,ISSFLO,ISSTRAIREAD,ISTORE \RITE( 7 134) UP, GNUP GNUU RITE(7. 135) ITMAX,DELT,TMAX, ITCYCDTMULT,DTMAX,NPCYC.NUCYC R1TE(7.136) NPR1NT,KNODAL,KELMNT.KINC1D,KPLOTP,KPLOTU,KVEL.B IUDG RITE(7, 137) ITRMAXRPMAX.RUMAX flITE(7, 138) COMPFL,CW,SIGMAW,RHOWO,URHOWO,DRWDUVISC0 RITE(7. 139) COMPMA.CS,SIGMAS.RHOS 'PfTE(7.141) ADSMODCHII.CHT2 1R1TE(7.142) PRODFOPRODSOPRODFI,PRODF2 1RJTE(7, 143) GRAVX,GRAVY R1TE(7,144) SCALX,SCALY,SCALTH,PORFAC FORMAT(2E10.3) F0RMAT('NODF,',6X,4E10.3) FORMAT(4E10.3) F0P1AT( A4 6X 2E 10.2)
FORMAT(4E10.3)
F(RMAT(7E10.3) FORMAT(T102E10. 3) FORMAT(615) FORMAT(15,2E15.3,110,E10.3,E15.3,215) FOHMAT( El 0. 3 , 2E1 5.3) FORMAT(515) FORMAT(1015) FORMAT( IA1O/ IAIO) FORMAT(1Al2) NE': = N \ NFY r NY- I D\L=XL/NEX DY L = VI. / N EY RTTE(*,1002) NNJJE 1002 FORMAT(/I/5X, 'TOTAL NUMBER OF NODES : '15/ 15) 15X, ' TOTAL NUMBER OF ELEMENTS : IF(NX.GF.NY) ICASE=I IF(NY GE.NX) ICASE2 1 IF(ICASE.NE. 1) GOTO 2 NI =NY N2=NX DL =DYL DL2 = DXL IF((XL,GT.0,AND.YI..GT.0).0 R. (XL. LT. 0. AND. VL. LT . 0)) THEN IC 1 = I IC 2 = U ELSE IC I iC2 I END IF 2 IF(1CASE.NE.2 ) GOTO 7 N I rNX N'2 = NY
266
DLI= DXL DL 2 = DYL IF((XL.GT.O.AND.YL.GT0)0R (XL.LT.0.AND.YL.LT0)) THEN Id =0 1C2=1 ELSE 1C1' I IC2'O END IF CONTINUE 1=0 DO 10 12=1,N2 DO 10 I1=1,Nl 1=1+1 POR=l .00000 THICK = t .000DO C1=(I1-1 )*DLI 1411 C2=(12-1 )*DL2 GOTO (11,12), ICASE L WRITE(7,1003) I,C2,C1,THICK,POR GOTO 10 12 WRITE(7, 1003) I,C1,C2,THICK,P0R GOTO 10 1003 FORMAT( 15 , 5X , 2F 10.4, 1F10.3, 1F 10. 10 CONTINUE )(\')\ - . PMINFA I '.I-(iLc F0RiAT(ELEMENT',3X,7EIO3) 202 DO 7779 L=1,NE PMAX = 1 . 000 PiIN=1 ODD ANGLX'I .0000 ALMAX=l .000 ALMIN=l .000 ATN4AXI .000 ATMINI .ODO R1TE(71004) L,PMAX,PMTN,4NG1\.1M1N,ATM,AT4 7779 FORMAT((15,5X,3(1PfhO2) ,0PF10.3F10.3,F104,F1O4 1004 ,r (I CIt) kP1CTI] NE 0) GOTO 3501 GOTO 400! 3501 CONTINUE. 1DIPEC- I i L1NP1 =0 NCIINPI = 0 NCI!A P1=00 PBASE Z I .0E06 UBASEIO. 357E-2 R1TE(7,302) 1DIREC,N[.1NPI,NC11NP1,NCTt. FORMAT(415) R1TE(7306) PBASE FORMAT(E13.3) 306 'RTTE(7,306) UBASF. 4001 CONTINUE 1F(NS0P.F.Q.0 ) GOTO 5501 DO Ill! TI=I,NSOP RTTF.(7,308) IQCP(TI),QINC(IT).L 302
C(iT)
267
FORMAT(I 10, 2E1 5.3) CONTINUE WRITE(7 309) FORNIAT(80( '0')) 309 IF(NSOU.EQ.0) GOTO 6501 5501 DO 2222 11=1 ,NSOU WRITE(7 311) IQCU(II) ,QUINC(II) FORMAT(I10, iEl5.3) 311 CONTINUE 2222 WRITE( 7,309) IF(NPBC.EQ.0) GOTO 7501 6501 DO 1311 1=1,8 UBC( I )=0 131! DO 219 JJ=1,NPBC WRITE( 7,312) IPBC(J.J) ,PBC(J.J),UBC(JJ) CONTINUE 219 FORMAT(I5 , 2F10.2) 3192 FORMAT(15 ,2E2O.5) 312 WRITE(7 309) IF(NUBC.EQ.0) GOTO 8501 750! 00 4444 11=1 ,NUBC WRITE(7314) IUBC(II),HBC(II) FORMAT( 15, E20.5) 314 CONTINUE 4444 WRITE(7 .309) IF(NOBS.EQ.0) GOTO 9701 8501 WRITE(7,317) (IWW(II)1I1,NOBS) FORMAT( 1615) 317 CONTINUE 9701 LLLO NE! N I-i NE2=N2- 1 DO 20 1E2=1 ,NE2 DO 20 1E11 NEt LLLLLL+ I 1- =1EI±(1E2-1 )*Nt IN( I )=L IN(2L+1C1*N1TC2 IN(3)=I-+N1+1 TN(4 )L IC! + 1C2*NI 20 WRITE7,1005) LLL, (TN(LL) LLI .4) 1005 FORMAT( 516) OPEN (8,FILE'SECOND.DSS' STATUS 'UNKNOWN') TS 1 0. 0 RITE(8,8001) IS! DO 8877 11.13 DO 8878 ,J=1.8 TC(I,J)TC(I,J)/10000.O CONTINUE 8878 CONTINUE 8877 R!TE(*,3344) ((TT(IJ),J1 ,8),11 13) WRITE( ((TC(1,J),J1 .8),11 13) R1TE(8,80O3) ((TT(I ,.J) ,J=l 8) 1=1,13) RITE(8,8003) ((TC(I,J),J1 ,8),11 .13) FORMAT( I D20. 2) 800! 8003 FORMAT(4D20, 13) ENDFILE( 5) ENDFILE(7) ENDFILE(8) STOP E!E) 308 1111
268
APPENDIX - D rr4 . 32/s RAKNAD' 12 7 1 1 2500 10 1 00 20 08 26 00 00 99 0 1 1 1 999 5 1 62.31019 1.0IE-04 1.01E-04 0.OE-00 6.BE-04 6.6E-04 6.6E-04 6.6E-04 042 8 3.858E-05 0.0 16 3.858E-05 0.0 24 3.858E-05 0.0 32 3.858E-05 0.0 40 3,858E-05 0.0 48 0.00 0.0 56 0.00 0.0 64 0.00 0.0 72 0.00 0.0 80 0.00 0.0 88 0.00 0.0 96 0.00 0.0 104 0.00 0.0 8 -.00 0.0 16 -.00 0,0 24 -.00 0.0 32 -.00 0.0 40 -.00 0.0 48 -.00 0.0 56 -.00 0.0 64 -.00 0.0 72 -.00 0.0 80 -.00 0.0 88 -.00 0.0 96 -.00 0.0 104 -.00 0.0 104 .035 03 .035 102 .035 101 .035 100 .035 99 .035 98 .035 97 .035 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 0! 01 01 01 01 01 0! 01 01 01 01 01 of 01 01 01 01 01 0! 01 0! 01 01 01 10 01 01 01 01 01 01 01 20 13 01 01 01 01 01 01 35 20 10 01 01 01 01 01 35 30 20 10 01 01 01 01 35 30 25 20 10 01 01 01 35 35 30 25 15 10 01 0! 35 35 35 30 20 10 10 10 35 35 35 35 25 15 13 11
APPENDIX - F rr4 . 32/s' RAHESH\4MIAM ISALND' 12 7 888 50 1 00 27 16 26 00 00 99 0 1 1 1 999 5 1 62.31D19 1.0!E-08 1.OIE-08 O.OE-00 6.6E-04 6.6E-04 6.6E-04 6.6E-04 05 8 .0000132 0.0 16 .0000132 0.0 24 .0000132 0.0 32 .0000132 0.0 40 .0000132 0.0 48 .0000132 0.0 56 .0000132 0.0 64 .0000132 0.0 72 .0000132 0.0 80 .0000132 0.0 88 .0000132 0.0 96 .0000132 0.0 104 .0000132 0.0 8 -.00 0.0 16 -.00 0.0 24 -.001574 0.0 32 -.001574 0.0 40 -.001574 0.0 48 -.001574 0.0 56 -.001574 0,0 64 -.001574 0.0 72 -.001574 0.0 80 -.001574 0.0 88 -.001574 0.0 96 -.00 0.0 104 -.00 0.0 104 .035 103 .035 102 .035 tO! .035 100 .035 99 .035 98 .035 97 .035 1 .035 2 .035 3 .035 4 .035 5 .035 6 .035 7 .035 8 .035 35 35 35 35 25 25 15 10 35 35 32 30 20 10 05 01 35 35 30 25 10 01 01 of 35 30 15 10 01 01 of 01 35 30 15 10 01 01 01 of 35 25 15 01 01 01 01 of 35 25 15 Of 01 01 01 01 35 25 15 01 01 01 of 01 35 30 15 10 Cl 01 0! of 35 30 15 10 01 01 01 01 35 35 30 25 10 01 of 01 35 35 32 30 20 10 05 01 35 35 35 35 25 25 15 10
269
IXF
270
Coordinates of a few small hamlets of Ramanathapuram District referred in the text
SI
No
Location Name
Latitude
Longitude
1
Valinokkam
9010'
78038
2
Mandapam
90 17'
79° 12
3
Nayakulam
90 15'
78020
4
Adamcherri
90 13'
78° 31'
5
Pallamorkulam
9014'
78° 36'
C
Ervadi
9° 15'
78° 50'
Servammai
9° 12'
78° 35
8.
Mudalur
91 16,
78028
a
Pullangudi
9° 20
78° 26'
10
Kavanur
9° 22
78° 20'
11
Kulathur
90 18'
78° 26'
12
R.S. Mangalam
9° 40'
78° 55'
13.
Abiramam
9° 30'
78° 28'
14.
Sayalkudi
9° 12'
78° 28'
Devipattanam
9° 35'
78° 57'
r
16.
Rajamatam - in Tanjore dist. 100 Km north of this area.
17.
Mariyur
90 120
78° 42'
271
REFERENCES Ackermann, N.L. and Chang, Y.Y. (1971). Saltwater interface during groundwater pumping. Jour. Hyd. Div., ASCE, 97(HY2), pp.223-232. Anderson, M.P. (1976). Unsteady groundwater flow beneath strip oceanic islands, Wat. Resou. Res. v. 12. n. 4, pp.640-644. Andrew, R.W. (1981). Saltwater intrusion in the Costa de Hermosillo. Mexico, Groundwater, v. 19, n. 6, pp.635-647. Arora, C.L. and Bose, B.W. (1981). Demarcation of fresh and saltwater zones using electrical methods. Abohan area, Ferozpur Dist. Puniab. Jour. Hydrol., 49, pp.75-86. Ayers, J.F. and Vacher. H.L. (1983). A numerical model describing uns:eady flow in a fresh water lens. Water Res. Bull., 19, pp.785-792. Back. W (1961) Calcium carbonate sat. in groundwaters from routine analysis, USGS water supply Paper 1535-D. 14 P. Back. W (1963) Preliminary results of a study of calcium carbonate saturation of groundwaters of Central Florida, Int. Nat. Assn. Sci. Hydrol. 8.3, PP. 43-51. Back. W. and Hanshaw. B.E. (1965). Chemical geohydrology. Adv. Hycro Sciences-1. pp.49-109. Back. W. (1966). Hydrochemical facies and groundwater flow patterns in northern part of Atlantic Coastal Plain. U.S.G.S. Prof. Pap. 498-A, 42p. Badrinath S.D. Raman. V., Gadkari, S.K. Mahasisalkar V.A. and Deshpande V.P. (1964) Evaluation of calcium carbonate stability indices for Sabarmathi river water, Ind. Water works Assn. 16, pp. 163-168. Balasubramanian. A. (1980). Some aspects of groundwater investigations applied in the Swedish Int. 0ev. Auth. assisted project, CGWB. Coimbatore. Unpublished M.Sc. Thesis. Annamalai University, 95p. Balsubramanian. A. (1986). Hycrogeological investigations of Tambraparni River -Basin, Tamil Nadu. Unpublished Ph.D. Thesis, University of Mysore, 349p.
272
Balasubramaniafl, A. (1992). Simulation of saltwater encroachment in coastal aquifers - Experimental and numerical analysis. James Cook University of Northern Queensland, Australia, 84p. Balasubramanian, A., Sharma, K.K. and Sastri, J.C.V. (1985). Geoelectrical and hydrogeochemical evaluation of coastal aquifers of Tambraparni Basin, Tamil Nadu. Geophys. Res. Bull., v.23, n.4. pp.203-209. Balasubrarflaflian. A. and Sastri, J.C.V. (1989). Teonniques of aquifer parameter evaluation using pocket computers. Proc. Int. Workshop Appropriate method develpt. and management of grounwater resou. in developing countries. pp.461-468. Balasubramaflian A., Thirugnana Sambandam, R.. Chellasamy, R. and Radhaknshnan. V. (1991). HydrogeochemiCal studies in coastal aquifers of Tuticorin, Tamil Nadu. Proc. Vol. on Seminar on 0ev. Man. of Groundwater in irrigation and other water sec:ors, CWRDM. 309-317pp. Basak. (1982). Recovery in large diameter we!is. Re. No. GW/R-5/1981. Groundwater division. CWRDM. Calicut. Basokur. A.T. (1990). Microcomputer program for the direct interpretation of resistivity sounding data: Computers & Geosc:enes, v.16. n.4, pp.587-601. Bear. J. (1979). Hydraulics of groundwater. McGraw Hill, New York, 567p. Bear, J. and Dagan, G. (1964). Moving interface in coastal a q uifers, Jour. Hyd. Div., ASCE. 90(HY4), pp.193-216. Bear. J. and Kapular. I. (1981). A numerical soluUcn for the movement of an interface in a layered coastal aquifer. Jour. Hycrol., 50. pp.273-298. Bhandari N.M. Singhal, B.B.S and Mithal R.S., (1975) A study of calcium carbonate saturation and delineation of flow systems of groundwater in the carbonate rocks of Borunda-Bikaner area. Dist Jodhpur, Rajasthan, India, Alt. Del 3, Convengo Int. Nat. Sule acqe Southern area. pp 242-247. Bhimashankaran.V. LS, Patangay N S. Blndu Madav. V. and RRnga Rao, K.V. (1969). Geophysical investigations in and arcund Hyderabad. Techn. Paper 2. Geophys. Dept.. Osmania Universit\'. Hyderabad. pp.102-10.
273
Bhimashankaran, V.L.S. and Gaur, V.K. (1977). Lectures on exploration 'y-geophysics for geciogists and engineers, AEG, Pubi. Osmania Univ. Hyderabad, 449p. Biswas. A.B. and Chatterjee, RK. (1967). On representation of water table by grid deviation method, Bull. Geol. Soc. India., v.4, pp.12-14. Bonnet, M. and Sauty, J. (1975). Un modele simplifie pour la simulation des nappes avec intrusion salline (A simplified model of saltwater encroachment in an aquifer). I nt. Assoc. of Sc!. Hydrol., V.115. no.45-56. Bradbury, K.R. and Rothschild, E.R. (1985). A computerize: technique for estimating the hydraulic conductivity of aquifers from secific capacity data, Groundwater, 23, 2, pp.240-246. Bredehoeft, J.D. and Pinder. G.E (1972). Mass transport in towing groundwater, Wat. Resou. Res., v. 9. n. 1, pp.194-210. Bull. J.W. and Jenne, E.A. (1979). WATE02 - A computerisec chemical model for tracer and major element speciation and mineral equilibria of natural waters. Amer. Chem. Sod. Symposium Series 93, pp. 6-835. Cantatore, W.P and Volker. R.E. (1974). The numerical Sc Jtion of the steady interface in a confined coastal aquifer. Civil Engg. Trans. I.E. Aust., v. CE16, n. 2, pp.115-119. Chandrasekaran. D. and Usha Kumari, S. (1982). Chemis:r'y of groundwater along Malapuram Coastal aquifer. Tech. Report GW R-18/82, Kozhicode, Kerala, India, 15p. Chander. S., Kapur. RN. and Goyal. S.K. (1981). Analysis of oumping test using Marquardt algorithm. Groundwater. v.9, n.3, pp.275-27S. Chebotarev. 1.1. (1955). Metamorphism of natural waters in te crust of weathering. Geochim. Cosmcchim, Acta. v.8. pp.22-48: 137-17: 198-212.
274
Cobb, P.M., McElwee, C.D. and Butt, M.A. (1982). An automated numerical evaluation of leaky aquifer pumping test data: an application of sensitivity analysis. Kansas Geological Survey. Groundwater, Ser, 6. 55p. Contractor, D.N. (1983). Numerical modeling of satlwater intrusion in the northern Guam lens. Wat. Resou. Bull. v.19, n.5, pp.745-751. Conway, E.J. (1942). Mean geochemical data in relation to oceanic evolution, Proc. Irish Acad. Sect., B., 48. pp. 119-159. Cooley, R.C. (1971). A finite difference method for unsteady flow in variably saturated flow media: Application to single pumping well. Wat. Resou. Res. v.7. n.6, pp.1607-1625. Cooper. H.H. (1959). A hypothesis concerning the dynamic balance of fresh water and salt water in a coastal aquifer. Jour. Geophys. Res. v.64, n.4. pp.461 -467. Czar Necki. J. B. and Craig, R.W. (1985). A program to calculate aquifer transmissivity from specific capacity data for programmable calculators. Groundwater, v.28, n.5, pp.667-672. Das. U.C. and Ghosh. DR (1974). The determination of filter coefficients for the computation of standard curves or dipole resistivity sounding over layered earth by linear digital filtering: Geophysical prospecting. v.22, n.4, pp.765780. Das Gupta. A. (1983). Steady interface upconing beneath a coastal infiltration gallery, groundwater. v.21, n.4. pp.465-474. Das Gupta. A. (1985). Approximation of saltwater interface fluctuation in an unconfined coastal aquifer, Groundwater. v.23, n.6. pp.783-794. Das Gupta. A. and Jaish, S.G. (1984). Algorithm for Theis solution, Groundwater. v.22, n.2. pp. 199-206. Davies. J.C. (1973). Statistics and Data Analysis in Geology. John Wiley and Sons, New York, 810p.
275
Davies, S.N. and De Wiest, R.J.M. (1966). Hydrogeology. John Wiley and Sons, New York, 463p. Desai, R.J., Gupta. S.K., and Shah, M.V. (1979). Hydrochemical evidence of sea water intrusion along the Mangrid Chorwad coast of Saurashtra, Gujarat, Hydrol. Scence, Bull., 24 (1/3), pp.71-82. Dominico, PA. (1972). Concepts and models in groundwater hydrology. McGrawHill, New York, 280p. Driscoll,F. G . (1986). Groundwater and Wells. Johnson Filtration System Inc. St. Paul, Minnesota, 2 Ed. 55112. 1089 p. Dumpie, J.P. and Cullen, K.T. (1983). The application of a microcomputer in the analysis of pumping test data in confined aquifers, Groundwater, 21, pp.79-83. Essaid, H.I. (1984). A quasi three dimensional finte difference model for the simulation of fresh water and saltwater flow n a coastal aquifer system. M.S. thesis Stanford University, 128p. Essaid. H.I. (1990a). A multilayered sharp interface model of coupled freshwater and saltwater flow in coastal system. Model cevelopment and application, Wat. Resou. Res., v.26, n.7, pp.1481-1454. Essaid. H.I. (1990b). The computer model SHARP a quasi-three dimensional finite difference model to simulate freshwater and saltwater flow in layered coastal aquifer systems. U.S.G.S., Wat. Rescu. Inv. Report:90-4310. 181p. Fetter. C.W. (1972). Position of saline water interface beneath oceanic islands, Wat. Rescu. Res., v.8, n.5, pp.1307-1315. Fetter. C.W. (1988). Applied Hydrogeology. CBS Publishers, New Delhi. 592p. Freeze, R.A. and Cherry, J.A. (1979). Groundwater. P r entice-Hall, Inc. Englewood Cliffs, New Jersey, 604p.
276
Frind, E.G. (1982a). Simulation of long-term density dependent transport in groundwater. Adv. Wat. Resou., n.5, pp.72-88. Frind, E.G. (1982b). Seawater intrusion in cotinuous coastal aquifer-aquitard systems, Adv. Wat. Resou. v.5, pp.89-97. Galin, D.L. (1979). Use of longitudinal conductance in vertical electrical soundinginduced potential method for solving hydrogeologic problems, Vestrik moskovskOgO universiteta, Geologiya, 34, 3, pp.97-100. Ghyben, W. (1889). Nota in verband met de Voorgenomen put Borning Nabij Amsterdam. Tydschrift Van het Konin Kyky institute van Ingenisuers. The Hague, The Netherlands. P.21. Gibbs, R.J. (1970). Mechanisms controlling world's water chemistry, Science, 170, pp.1088-1090. Gilkesan, R.H. and Cartwright, K. (1983). The application of surface electrical and 9'7-hallow geothermal methods in monitoring network design, groundwatr monitoring Rev., v.3, pp.30-42. Glover, R.E. (1959). The pattern of freshwater flow in a coastal aquifer. J. Geophys. Res. v.64, n.4, pp.457-459. Gorham. F. (1961). Factors influencing supply of major ions to inland waters \'Iih special reference to the atmosphere. Bull. Geol. Soc. Amer., v.72, pp.795840. Guswa, J.H. and Le Blanc, D.R. (1981). Digital models of groundwater flow in he Cape Cod aquifer system. Massachusetts. Water Resour. Invest. Open ie rep. 80-67, 127p. GuvanSe-fl, V. (1979). Theoretical and experimental studies of clogging and contamination in aritifcial groundwater recharge. Ph.D. Thesis, James Cook University of North Queensland, Townsville, Australia, 352p. Guvanose.fl, V. and Volker, R.E. (1982). Solutions for solute transport in an uncoflfined aquifer. J. HydrOl., v.58, p.89-109.
277
Guvancsen, V. and Volker, R.E. (1983). Numerical solutions for solute transport in unconfined aquifers. !nt. J. Num. Methods in Fluids, v.3, p.103-123. Handa, B.K. (1964). Modified classification procedure for rating irrigation waters. Soil Sci., v.98, pp.264-269. Handa, B.K. (1965). Modified Hill-Piper diagram for presentation of water analysis data, Curr. Sc., 34, pp.313, 314. Haubold, R.G. (1975). Approximatinto freshwater aquifers. Jour. Geophys. Res., 64, 11. pp. 1911-1919. Hem, J.D. (1961) Geo chemistry of water; Calculation and use of ion activity, USGS watel supply paper, 1935-C, 17 P. Henriet. J.P (1975). Direct interpretation of the Dar Zarrouk parameters ir. groundwater surveys. Geophys. Prosp. v.24, pp.344-353. Henry, H.R. (1959). Salt intrusion into freshwater aquifers. Jour. Geophys. Res.. v.64, n. 11. pp. 1911-1919. Herzberg, A. (1901). Die wasserversorgung eininger nordsee Bader. J. Gasbeleucht. Verw Beleuchtungsarten WasserverSOrg, 44, pp.815-819, 842844. Hil de Brand (1962). Advanced calculus for applications. Prentice-Hall. Englewood Cliffs, New Jersey, 360p. Hubbert, M.K. (1940). The theory of groundwater motion. Jour. Geol., v.48, n.8. pp.785-944. Huyakorn. PS., Anderson, RE Mercer. J.W. and White Jr., H.O. (1987). Saltwater intrusion in aquifers: Devleopment and testing of a three dimensional finite element model. Wat. Resou. Res., v.23, n.2, pp.293-312. nouchi, K, Kishi, Y. and Kakinuma. T. (1985). The regional unsteady interface between freshwater and saltwater in a confined coastal aquifer. J. Hydrol. v.77, pp.307-331.
278
INTERA (1979). Revisions of documentations for a model for calculating effects of liquid waste disposal in deep saline aquifers, U.S.G.S. Wat. Res. Inv. Rep. pp.79-96. Isaacs, L.T (1985). Estimating interface advance due to abrupt changes in replenishment in unconfined aquifers, J.Hydrcl., 78, pp.279-289. Isaacs, L.T. (1987). Parametric study of interfacce advance rates in unconfined aquifers. Res. Report n. CE 83, University of Queensland. Isaacs, L.T. and Hunt, B. (1986). A simple approximation for a moving interface in a coastal aquifer. J. Hydrol. v.83, pp.29-43. Karanjac. J. (1975). Brief note on testing the possibility of defining optimum yield of dug wells of large diameter, groundwater, 13, 4. ranjac. J. and Bratice vic (1987). Microcomputer programs in BASIC. Elsevier Pub. Amsterdam, 320p. Kashef. Al. (1983). Harmonizing Ghyben-Herzberg interface with rigorous solutions. Groundwater. v.21, n.2. pp.153-1 59. Kashef, Al. (1986). Groundwater Engineering, McGraw-Hill Book Company. New York, 512p. Kashef, Al. and Smith, J.C. (1975). Expansion of saltwater zone due to well discharge. Wat. Resour. Bull.. v.11, n.6. pp. 1107-1120. Keller. G.V. and Frischkrect. F.C. (1966). Electrical methods in geophysical prospecting. Pergamon Press, London. 517p. KemblowSki M. (1985). Saltwater-freshwater transient upconoing an implicit boundary element solution, J. Hydrol. v.78, pp.35-47. Kipp. K.L. (1987). HST3D: A computer code for simulation of head and solute transport in three dimensional groundwater flow systems, USGS, Wat. Resour. Invest. Report, 80-26. 517p.
279
Kishi, Y., Fukuo, Y., Kakinuma, T. and Ifuku, M. (1982). The regional steady interface between freshwater and saltwater in a coastal aquifer. Jour. Hydrol. 58, pp.63-82. Kohout, FA. (1964). The flow of fewhwater and saltwater in the Biscaye aquifer of the Miami area, Florida, In. Seawater in coastal aquifers, USGS water supply paper 16130, pp-12-32 Kollert, R. (1969). Groundwater exploration by the electrical resistivity method, - Geophys. Memo, 369, 7p. Krupanidhi, K.V.J.R.. Venkataraman, S., Mathuria. DR and Murthy, K.N. (1973). Studies of specific capacities of wells in hard rocks and alluvial formations of Mysore State. mt. Natl. Symp. Proc. Deve. of groundwater resources, Madras, India. 0, pp.1la6l-74. Kruseman, G.R and De Ridder. N.A. (1970). Analysis and evaluation of prumping test data. Int. Nat. Inst. for land reclamation and improvement, Wageninger. The Netherlands, 200p. Kumarasamy, P. (1973). Laminar inflow theory for hard rock open wells, Ind. Gehydrology, OX, n.5. Labadie. J.W. and Helweg. O.J. (1975). Step drawdown test analysis by computer, groundwater, v.13, n.5. pp,438-444. Larson, T.E., and Boswell AR., (1942)Calcium Carbonate indices and alkalinity interprE tation Am. Wat. Works Assn. Jour., 34, pp 1667-1687. Lawrence, A.R. (1985). An interpretation of dug well performance using a digital model v.23. n.4. Groundwater, July-Aug. Lawrence. J.F. and Balasubramantan (1994). Groundwater condiitiOflS and disposition of slatwater interface in the Rameswaram Island, Tamil Nadu. Reg. Wrokshop on Environmental aspects of groundwater Dev. Oct. 17-19, 1994. Kuru kshetra, India. pp. III 21-25. Lee, C.H. and Cheng. R.T. (1974). On seawater encroachment in coastal aquifers, Wat. Rescu. Res. v.10. n.5. pp.1039-1043.
280
Lirnaye, D.G. (1973). Discussion on studies of specific capcaity of wells in hard rocks and alluvial formations of Mysore State by Krupanidhi and others. Prc. mt. Nat. Symp. on Groundwater reosurces, Madras, India, v.IV, pp2-8. Liu, C.C.K., Lau, L.S. and Mink, J.F (1981). Numerical simulations of a thick freshwater lens: Pearl Harbour groundwater model, University of Hawaii. MacKenzie, FT. and Garrels, R.H. (1965). Silicates: Reactivity with seawater. Sci.150, pp.57-58. MacKenzie, FT. and Garrels, R.H. (1966). Chemical mass balance between rivers and oceans. Amer. Jour. Sci. v.264. pp.507-525. Marilingaiah, P (1978). Determination of hydrogeolOgiCal parameters of the rock types of Husu taluk. Mysore, District. Karnataka, M.Tech (Hydrogeology Dissertation (unpublsihed), University of Mysore. 71p. Matzner, R.A. (1983). HydrogeolOgic and geophysical investigations of the Springfield-Black fort area, Idaho, Pap. presented during the Tech. Edn. Sessn. 1983. Expo. 43p. McElwee. C.D. (1980). Theis parameter evaluation from pumping test by sensitivity analysis. Groundwater v.18, n.1 pp.56-0-0. McElwee. C.D. (1985). A model study of saltwater intrusion to a river using the sharp interface approximation. Groundwater, v.23. n.4, pp.465-475. McElwee. C.D. and Kemblowski, M. (1990). Theory and application of an approximate model of saltwater upconing in aquifers. Jour. Hydrol. 115, pp. 1 39-163. Meinardus. H.A. (1970). Numerical interpretation of resistivity sounding over horizontal beds. Geophys. Prosp., v.18. pp.63-81. Meinzer. O.E. (1923). The occurrence of groundwater in the United States, with a discussion on principles, U.S.G.S Water suppply paper 489. Go. Printing Office, Washington, D.C., 321p.
281 Melanchthon, V.J. Raju, V.N., Ramarkshinan, A., and Bhowmick, A.N. (1988). Resistivity survey for mapping freshwater pockets. J. Assoc. Expi. Geophys. Memo. 4/71, 12p. Mercer, J.W, Larson, S.F. and Faust, C.R. (1980a). Finite-difference model to simulate areal flow of saltwater and freshwater separated by an interface, U.S.G.S. Open file Rep. 80-407,88p. Mercer, J.W., Larson, S.F. and Faust, C.R. (1980b). Simulation of saltwater interface motion. Groundwater, v.18, n.4, pp.374-384. Mining, R.C. (1973). The electrical resistivity method, Part I. Technical Memo No.3, Water well Jour. v.27, n.6 Mooney, H.M., Orellana, E., Picket, H. and Tornheim, L. (1966). A resistivity - computational method for layered earth models. Geophysics, v.31, pp. 192203. Morgan, C.O. and Winner Jr. M.D. (1962). Hydrochemical facies in the 400 foot and 600 ft sands of the Baton Rouge Area, Lousisiana, U.S.G.S. Prof. Pap. 450-B, pp. 120-121. Mualem, Y. and Bear, J. (1974). The shape of the interface in steady flow in a St ratified aquifer, Water Reou. Res. v.10, n.6, pp.1207-121 5. Mukhopadhyaya. A. (1985). Automated derivation of parameters in a non-leady confined aquifer with transient flow, groundwater, v.23, n.6, pp.806-81 1. Muskat, M. (1937). The flow of homogeneous fluid through porours media. McGraw-Hill, New York, 763p. Narasimhan. TN. (1965). On testing open wells, Ind. Geo-hydrology, 1, pp-101105. Nautyal, M.D. and Gopalappa, V. (1980). Yield characteristics of open wells in crylline rocks of Chikkahagari basin, Karnataka, Jour. Ind. Assn. Hydrol. v.4, n.1&2. lop.
282
Niel, PL., Johnes, L.F. and Truesdell, A.H. (1984). WATEOF - A FORTRAN -IV version of water quality assessment program for calculating chemical equilibrium of natural waters. U.S.G.S Wat. Res. Inv. Reprt, 73-13, 70p. N.R.C. (1990). Groundwater models, Scientific and regulatory applications National Res. Council, Nat. Acad. Press, Washigton DC. 303p. O'Neil, D.J. (1975). Improved linear coefficients for applicationharP modelling approaches. J. Hydrol., v.56, pp.239-250. Palmquist, W.N. (1973). Sampling for groundwater quality investigations, Dept. of Mines and Geol. Government of Karnataka, Groundwater Studies, 125, 14p. Pandyal, G.N. and Das Gupta, A. (1986). A microcomputer package for determining optimal well discharge. Groundwater, v.24, n.5.. Parkhust, D., Tharstenson, D.C. and Niel, PL. (1990). PHREEQE - A computer program for geochemical calculations. U.S.G.S. Wat. Res. Inv. Report 8096, 195p. Patangay. N.S. and Murah, S. (1984). Geophysical surveys to locate groundwater '-esources for rural water supply. UNICEF course pub. CEG, Osmania University, Hyderabad, 166p. Pinder, G.E and Cooper, H.H. (1970). A numerical technique for claculating the transient position of the saltwater front. Wat. Resou. Res. v.6, n.3, pp.875882. Pinder, G.E and Page, R.H. (1977). finite element simulation of seawater intrusion on the south fork of Long Island. ln:Finite elements in water. Resou. Proc. of the first mt. conf. on Finite elements in water resour. Pentech, London,pp.251 -269. Polo, J.F. and Ramis, F (1983). Simulation of saltwater-freshwater interface motion. Wat. Resou. Res. 09, n.1,pp.61-68.
283 Piper, A.M. (1944). A graphic procedure in the geochemical interpretation of water analyses. Transactions American geophysical union, v.25, pp.914923. Prasad, N.N.B. (1984). Hydrogeological studies in the Bhadra River Basin, Karnataka unpublished Ph.D., Thesis, University of Mysore, 323p. Public Works Department (1977). Geology of Tamil Nadu. Departmental Report (Unpublished). 68p. Raghu, K.C., Nagendra, R. and Patangay, N.S. (1991). RESDYK )A FORTRAN program for computing apparent resistivity overan infinitly deep outcropping vertical dyke. Computers & Geosciences, v.17, n. 10, pp. 1395)1408. Raghunath. H. (1987) Groundwater, Wiley Eastern Ind. Ltd. New Delhi, 2 99 p. Rajagopaian, S.F (1982). Analysis of dug well test data, Rep.No.GW/R 36/82, Groundwater division, CWRDM, Calicut. Rajagopalan, S.F. Abraham, S. and Prabha Sankar, P.N. (1983).Pumping tests and analysis of test data from open wells in coastal tract of Trivandrum district, Rec. GW/R-92/83. Groundwater Division, CWRDM, Calicut. Ramachandran. T.V. (1987). Integrated study of LANDSAT Aeromagnetic and Bouguer Gravity anomaly data or geological appraissal - A case study from Tamil Nadu, India. Proc. of the eighth Asian conf. on Remote Sensing held at Djakarta, pp.0-11-1 to 011-6. Ramachandran, TV. (1991). Regional geological study of the granitic belt of South India using multi theme data. Ph.D. thesis (Unpublished), Andhra ) University. 202p. Ramesem, V. and Barua. S.K. (1973). Preliminary studies on themechanism controlling salinity in the north western andregions of India. Ind. Geohydrology, v.9, pp.10-18. Ram Mohan, H.S. (1984). A climatological assessment of the water reources of Tamil Nadu. Ind. J. Power and River valley Dev., pp.58-63.
284
Rathod, K.S. and Rushton, K.R. (1984). Numerical method of pumping test analysis using micro computers. Groundwater. v.22, pp, .602-608. Rayner, F.A. (1980). Pumping test analysis with ahard held calculator, Groundwater v.18, n.6, pp.562-268. Reddel, D. and Sunada, D. (1970). Numerical simulation of dispersion in groundwater aquifers, Hydrol. Pap. no.41. Colorado State University, Colorado, 79p. Reilly, T. and Goodman, A.S. (1985). Quantitative analysis of satwater freshwater relationshp in groundwater system a historical perspective, Jour. Hydrol. 80, pp. 125-160. Rengaraiafl, R. and Balasubrarnanian, A. (1990). Corrosion andscale formation characteristics of groundwater in and around Nangavalli, Salem Dist., Tamil Nadu. J. App. Hydrol, v.111, n.2, pp.15-22. Richards L.A. (1954) Diagnosis and improvement of saline and alkali soilsAgri Hand book 60 U.S. Dept. Agri. Washington D.C. 160 pp. Roberson, C.E (1964) Carbonate equilibrium in selected natural waters. Am. Jour Sc., 262, 4, pp. 56-65. Rubin, H. and Finder, G.E (1977). Approximate analysis of upconing, Adv. Wat. Resour. v.1, n.2, pp.97-101. Rumer Jr. R.R. and Harleman, D.R.F (1963). Intruded saltwater wedge in porous media. Proc. ASCE v.89, n.HY6, pp. 193-220. Rushton, K.R. and Booth, S.J. (1976). Pumping test analysis using discrete time discrete space numerical method. Jour. Of Hyrol, v,28, pp.13-27. Rushton, K.R. and Singh, V.S. (1987). Drawdowns in large diameter wells due to decresing abstraction rates, Groundwater, v.21, n.6, pp.670-677. Ryzner, J.W. (1944) A new index for determining amount of calcium carbonate scale formed .472-486. by water, J. Amer. W.W. Assn.. 36. Sakthimurugafl, S., Chellasamy, R. and Balasubramanian, A. (1991). Resisitivity measurement over granular porous media saturated with fresh and saltwater. Reg. Sem.Groundwater Dev. Prob. in South. Kerala. pp. 43-53. Sakthimurugan, S. (1994). HydrogeologiCal studies and simulation of contaminant migration in and around Dindigul, Anna District, Tamil Nadu. . ,. , ,_: . 1 A ri (rcnt
285
Sammel, E.A. (1974). Aquifer tests in large diameter wells in India. Groundwater v.12, n.2, pp.265-272. Sanford, W.E. and Konikow, L.F. (1985). A two constituent solute transport model for groundwater having variable density. U.S.G.S. Wat. Res. Inv. Report-854279, 88p. Sanil, R. and Balasubramanian, A. and Sastri, J.C.V. (1994). Potential zones for groundwater development in Tambraparni river basin. Tamil Nadu, India. Regional workshop on env. Aspects of Groundwater Devel. Oct.17-19, 1994, Kurukshetra, India. II pp.37-42. Sankar, K., Jegatheesan, M.S. and Balasubramanian, A. (1993). Hydrogeological studies in the Kanyakumari District, Tamil Nadu, Proc. Vol. Reg. Sem. Groundwater Devel. Problems in southern Kerala, CWRDM, pp.12-21. Sastri, J.C.V. and Lawrence, J.F. (1988). Hydrogeochernical evaluation of Karaikudi environs. Tamil Nadu, India, Geophysics, Res. Bull. v.26, ni, pp.39-43. Sastr;, J.C.V., Marlingaiah, P and Narasimha Prasad, N.B. (1983). Dug well performance in hard rock areas of Hunsu taluk, Mysore District, Karnataka, Jour. A.E.G. v.4, n.2,pp.39-43. Sathyamoorthy, K. and Banerjee, B. (1985). Resistivity surve y s for locating brine pockets in the little Rann of Kutch, Gujarat. J. Assn. ExpI. Geophys. v.VI, n.2, pp.7-13. Sathyamoorthy, S. (1984). Chemical quality of groundwater from pliocene and lower miocene aquifer of Cauvery Delta. M.Phil Dissertation (Unpublished), R.E.C., Tiruchi, 71p. Sathyamoorthy, S. (1991). Integrated groundwater studies in and around Tiruchirapalli, Tamil Nadu. Unpublished Ph.D. Thesis, Bharathidasan University, Tiruchi, 258p.
286
Sarvenhje, H.H.G. (1989). Salt intrusion model for high waterslack, low water slack and mean tide on spread sheet, Jour. Hydrol. 107, pp.9-18. Scarascia, S. (1976). Contribution of geophysical methods to the mangement of water resources, GeoexploratiOn, 14, pp.265-266. Schoeller, H. (1965). HydrodynamiqUe dans lekarst (Ecoul emint et enmagasminemnt- Actes Collogue Dobronik, I, pp.3-20. AIHS et UNESCO. Schoeller, H. (1967). Qualitative evaluation of groundwater resources (in methods and Techniques of groundwater investigation and development). Wat. Res. Series-33, UNESCO, pp.44-52. Segel, G. Finder, G.F. and Gray, W.G. (1975). A Galerkin-finite element technique for calcuatling the transient position of the saltwater front, water. Resou. Res. v.11, n.2, pp.343-347. Sen, Z. (1986). Determination of aquifer parameters by the slope matching method, groundwater, v.24, n.2, pp.217-223. Shamir, V. and Dagan, G. (1971). Motion of sea water interface in coastal aquifers: A numerical solution, Water Resour. Res., v.7, n.3, pp.644-657. Sh,,rm. PV. (1976). Geophysical methods in geology, series-12. Methods in /V geochemistry and geophysics. Elsevier, Sci. Pub. co. 428p. Sharma. S.N.N. (1982). HydrogeologiCal investigation in Varada Baisn, A subtributaroy to Krishna river, Karnataka. Unpublshied Ph.D. Thesis Univ. of Mysore, 125p. Sheriff, R.E. (1973). Encyclopaedia dictionary of exploration geophysical society of exploration. Singh, V.S. and Gupta, C.R(1988). Analysis of pump test data for a large dimaeter well near a hydrogeologiCal boundary. J. Hydrol. v.103, pp.219-227. Singhal, B.B.S. (1973). Some observations on the occurrence uttisation and managemnet of groundwater in the Deccan Trap areas of Central
287
Maharashtra, India, Proc. mt. Symp. DevI. Groundwater resource,s Madras, India. 3, v.3 pp.75-81. Singhal, D.C. (1984). An integrated approach for groundwater investigation in hard rock areas-A case study. mt. Workshop on Rural hydrogeology and hydraulics in fissured basement aeas, pp.87-93. Singhal, D.C. Sriniwas and Singhal, B.B.S. (1988). Integrated approach to aquifer delineation in hard rock terrai - A case study from Banda District, India. Jour. Hydrol. v.98, pp.165-183. Slichter. C.S. (1902). The motions of groudwater, \Vashington, D.C.. USGS Wat. Supply Pap. 153, 61p. Slichter, C.S. (1906). The underflow in Arkansas vaey in western kansas, USGS Wat. Sup. Pap. 153,61p. Srinivas and Singhal, D.C. (1985). Aquifer transrn:ssivity of prous media from resistivity data. Jour. Hydrol. v.82, pp. 14.3-153. Srinivasan, P.R. (1992). Hydrogeological studies of Mamundiyar River Basin, Unpublished Ph.D. Thesis, Bharathidasan University, Tiruchi. 362p. Sriniwas (1975). Direct interpretation of gecelectric measurements by the use of linear filter theory. Geophysics. v.40, n. 1, pp. i 21-122. Sriniwas. Pawan Kumar and Wason, W.R. (1982). Fast automatic solution of the inverse resistivity porbiem. Proc. Ind. Acad Sci. (Earth Planet. Sci.), v.91, ni, pp.29-41. Stewart, M.T (1982). Evaluation of electromagnetic method for rapid mapping of saltwater interface in coastal aquifers. Groundwater, v.20, n.5. pp.235-545. Stewart, M.T. Michael Layton and Theodore Linazac (1983). Application of resistivity surveys to regional hydrogeolagica reconnaissance. Groundwater, V.21, n.1, pp.42-48.
288 StreJtsova, 1. D. and Kashef, A.T. (1974). Critical state of saltwater upconing beneath artesian discharge wells, Wat. Resou. Bull. v.10, n.5, pp.995-1008. Stuyfzand, P.J. (1986). A new hydrochemical classification of water types. Principles and application to the coastal dunes aquifer system of the Netherlands. Proc. 9th Saltwater Intrusiion Meeting, Delft, 12-16, May, Delft University of Technology, pp.641-655. Stuyfzand, P.J. (1989). A new hydrochemical classification of water types with examples of applciatiofl IAHS. 184, pp.89-98. Stuyfzand. PJ. (1990). HydrochemCal facies analysis of coastal dunes and adjacent low lands - The Netherlands as an example. Catena, supplement 18, pp. 121-132. SubramaflJafl. A. (1975). Specific capacity of wells in hard rocks - A study, symp vol. hydrol. Roorkee, pp. E. 16-19. ,,Subramanian, S. (1994). Hydrogeological studies in the coastal aquifer of Tiruchendur. Tamil Nadu, Unpubisihed Ph.D. Thesis Manonmaniam Sundaranar Univ. Tirunelveli, 308p. Subramaflian, S. and Balasubramaflian A. (1994). Hydrogeochemlcal stuides of Tiruchendure coast, Tamil Nadu, India. Reg. Workshop on Env. Aspects of Groundwater Devel. Oct. 17-19, 1994, Kurukshetra, India. pp. MI 26-32. Sukhija. B.S., Varma. V.N., Nagabhushanam. and Reddy, D.V. (1994). Origin of salinity in coastal aquifers of Karaika! and Tanjavur area of Cauvery Delta. India. Reg. Workshop on Env. Aspects of Groundwater Dev. Oct.17)19, 1994. Kurushetra, III pp.33-42. Summers W.K. (1972). Specific capacity of wells in Crystalline rocks, Groundwater v.10, n.6, pp.37-47. Swartz, J.H. (1937). Resistivity studies of some saltwater boundaries in the Hawaiian Islands. Trans. Amer. Geophysical Union. v.18. pp.387-393.
289
Taigbenu, A.E. and Ligget, J.A. (1984). Boundary integral solution to seawater intrusion into coastal aquifers, Wat. Resou. Res. v.20, n.8, pp. 1150-1158. Telford, W.M. Geldart, L.P., Sheriff, K.E. and Key, D.A. (1976). Applied 4-2--Geophysics, Cambridge Univ. Press, 860p. Theis, C.V. (1935). The relation between the lowering of the piezometric surface and the rate and the duration of discharge of a well using groundwater storage, Am. Geophy. Union Trans. 16, pp.519-524. Theis, C.V. (1963). Estimating transmissibility of water table aquifer from specific capacity of wells (in methods of determing permebaility transmssibiility and draw down compled by Bay Bentall). USGS Water supply paper, 1536-1. pp.332-336. Todd, D.K. (1980). Groundwater Hydrology, John Wiley and Sons. New York, 535p. Van Dam, J.C. (1983). The shape and position of saltwater wedge in coastal aquifers. Relation of groundwater quantity and quality, Proc. of the Hamburg symposium, August, IAHS PubI. No.146. pp.59-75. Van der Veer. P. (1977a). Analytical solution for steady interface flow in a coastal aquifer involving a phreatic surface with precipitation. J. Hydrol., v.34, pp. 1-11. Van der Veer, F (1977b). Analytical solution for a two fluid flow in a coastal aquifer involving a phreatic surface with precipitation. J. Hydrol., v.35, pp.271-278. Vander Velpan. B. PA. L. (1988). Forward resistivity model, M.Sc. Research project I.T.C. kannel Weg, 32628. Delft, The Netherlands. Vappicha, V.N. and Nagaraja, S.H. (1976). An approximate solution for the transient interface in a coastal aquifer, Jour. Hydrol. 31, pp.161-173. Varadaraj, N. and Parthasarathy, T.N. (1986). Groundwater Resources and Develo. Potential of Ramanathapuram District, Tamil Nadu State. C.G.W.B. Report, 42p.
290
Vingoe, P (1972). Electrical resistivity surveying, ABEM *Geophys. Memorandum 5/72, 16p. Viswanathiah, M.N., Sastri, J.C.V. and Ramegowda, B. (1978). Mechanism controlling the chemistry of groundwater of k'arnatak, Ind. MineralOiSt, 19, pp.65-69. Volker, R.E. (1980). Comparison of miscible and immiscible fluid models for seawater intrusion in aquifers. 7th Australian Hydraulics and fluid mech. conf. Brisbane: Queensland. pp.23-26. Volker, R.E. and Guvanesan. V. (1979). Finite element solution for pollutant movement in aquifers. Proc. 3rd Int. Conf. on Finite element methods. Univ. of New South Wales. Australia, pp.613-627. Volker, R.E., Marino, M.A. and Rolston, D.E. (1985). Transition zone width in groundwater on ocean atolls. Jour. Hydrol. Engg. III (4), pp.659-676. Volker, R.E. and Rushton. K.R. (1982). An assessment of the importance of some parameters for seawater intrusion in aquifers and a comparison of dispersive and sharp modelling approaches. J. Hydrol., v.56. pp.239-250. Voss, C.I. (1984a). AQUIFEM-SALT A finite element model for aquifers containing a seawater interface. U.S.G.S. Wat. Resou. Inv. Rep. 84-4263, 37p. Voss, Cl. (1984b). SUTRA: A finite element simulation model for saturated-unsaturated fluid density dependent groundwater flow with energy transport or chemically reactive single species solute transport, U.S.G.S. Wat. Resou. Inv. Rep. 84-4369, 409p. Walton, W.C. (1962). Selected analytical methods of well and aquifer evaluation. Illinois State water survey Bull. 49, 31p. Walton, W.C. (1970). Groundwater resource evaluation. McGraw-Hill, New York, 664p.
291 arner, D.L. and Yow, M.G. (1980). Programmable hand calculator program for pumping and injection wells constant pumping (inj. rate) sinlge penetrating well semi confined aquifer. Groundwater. v.18, n.2, pp.126-133. ilson, J. and Sa Da Costa (1982). Finite element simulation of a saltwater/freshwater interface with indirect toe tracking. Wat. Resou. Res., v.18, n.4, pp. 1069-1080. orthington, RE (1977). Interfluence of matrix conduction upon hydrogeological relationship in arenaceous aquifers water. Resour. Res. 13.1 pp.87-92. h, H.D. (1985). Discussion on numerical determination of aquifer constant by SR RA., Jour. Hydraul. Engg. ASCE. v. III, n.7, pp.432-439. zel, A.J. Walton, W.C., Sasman, R.T. and Pricket, T.A. (1962). Groudwater resources of Du page country, Ilinois, Illinois State Wter survey coperative groundwater project 2.. hdy, A.R.R. (1969). The use of schiumberger and equatorial soundings in groundwater investigations near El Paso Texas, Geophysics, 34, pp.713728. hdy, A.R.R. (1989). A new method for the automatic interpretation of Schiumberger and Wenner Sounding Curves. Geophysics. v.54, n.2, pp.245-253. ohdy, A.R.R., Eaton, G.P. and Mobey, D.R. (1974). Application of surface geophsycis to groundwater investigationsin. Tech. Water Res. Inv. USGS book 2, CDS, 116p.
