scale irrigation in SW Saudi Arabia. ▫ Introduction project ... desert of South West
Saudi Arabia under present day climate ... Monsoon air stream. Mediterranean.
Meteorological impact assessment of possible large scale irrigation in SW Saudi Arabia Ronald Hutjes, Herbert ter Maat, Berny Bisselink Ryohji Ohba, Hiromasa Ueda
3rd EU Japan meeting Jan 2005
Meteorological impact assessment of possible large scale irrigation in SW Saudi Arabia
Introduction project objectives and structure Model implementation, validation Meteorological impact assessment Conclusions
3rd EU Japan meeting Jan 2005
Introduction
Effects large scale landuse/cover change well documented z z z
Sahel desertification, etc Amazonian deforestation, etc US agrification, etc
One way forcing Two way interaction leading to (mutliple) stable climate-vegetation states
3rd EU Japan meeting Jan 2005
Introduction
Effects large scale landuse/cover change well documented
z Sahel desertification, etc J A S d if f e r e n c e s (m m ) z Amazonian deforestation, O b s eetc r v e d ‘8 0 -’5 0 z US agrification, etc
O N D d if f e r e n c e s (m m )
One way forcing Two way interaction leading to (mutliple) stable climatevegetation states S im u la t e d ‘8 0 -’5 0
3rd EU Japan meeting Jan 2005
Introduction objective
To evaluate the meteorological effects of manmade oasis-like constructions in the coastal desert of South West Saudi Arabia under present day climate, under varying monsoonal influences, and under changed climate
3rd EU Japan meeting Jan 2005
Introduction: research area Inland ・Precipitation 2000m) ・Precipitation 2500m)
Task 4: Green enhancement Task 3: Water Resource
Task 5: Environmental assessment
3rd EU Japan meeting Jan 2005
Project lay out hi-res modelling
Jeddah, Mecca region z z z z
Less topography mostly mediterranean disturbances that brings rain MM5 model Kyoto University
Ahba, Gizan region z z z z
High topography Mostly indian ocean monsoon circulation that brings rain RAMS model Alterra and MHI
3rd EU Japan meeting Jan 2005
Model implementation, validation
Introduction project objectives and structure Model implementation, validation Meteorological impact assessment Conclusions
3rd EU Japan meeting Jan 2005
Model implementation, validation
Grid resolutions z z z
1: 80 km resolution 2: 16km resolution 3: 4km resolution
USGS Topography USGS Landcover IGBP Soils ECMWF SST
3rd EU Japan meeting Jan 2005
Model implementation, validation
RAMS implemented on Earth Simulator 10 nodes / 80 cpu
1.2 1
Efficiency
0.8 0.6 0.4 0.2 0 0
10
20
30
40
RAMS efficiency on ES
50
Number of CPU's
60
70
80
90
Model implementation, validation Various datasets to validate the model results
Dataset obtained from Presidency Of Meteorology & Environment (daily values of wind, temperature and rainfall)
NASA Remote Sensing Validation Data (5 minute values of shortwave, temperature and relative humidity values
Satellite images EUMETSAT
TRMM
Observations ECMWF
Model implementation, validation
Importance: local systems probably determine orographic rainfall, especially after land cover change
CONTROL RUN: 21 february - 19 april (- 31 may) 2000 RAMS output grid3 vs stations (ECMWF-MARS) Abha, Gizan, Khamis Mushait (2m-Temp and to 10m-wind at proper station altitude)
Case studies & long term statistics T, U , Udir, P
RAMS output grid 1 vs TRMM
z z
Monthly mean precipitation 3D microphysics
3rd EU Japan meeting Jan 2005
Validation vs Groundstations Wind direction
Mecca
Jeddah observed
300
350 Wind direction [degree]
Wind direction [degree]
350
Feb
400
modelled
400
250 200 150 100 50
250 200 150 100 50
2/3/2000
0 2/1/2000
2/5/2000
400
modelled
400
350
observed
350
Wind direction [degree]
May
Wind direction [degree]
0 2/1/2000
300
300 250 200 150 100 50 0 4/17/2000
2/3/2000
2/5/2000
300 250 200 150 100 50
4/19/2000
4/21/2000
4/23/2000
0 4/17/2000
Sea Breeze
4/19/2000
4/21/2000
4/23/2000
TRMM
validation RAMS
TRMM used for •large scale validation (Convection)
•Small scale validation (Microphysics)
Grid 1
RAM S 3rd EU Japan meeting Jan 2005
Validation vs TRMM High resolution vertical profile TRMM (2A12, TMI) compared to RAMS microphys 16 march 2000 Cloud water TRMM single peak at 1.5 to 3 km alt RAMS dual peak at 1 to 3km x10-3
Alt 750 1750 2750 3750 5500 9000 m
3rd EU Japan meeting Jan 2005
Model implementation, validation
Temperature
Especially in cooler months
Wind
overestimation at daytime (Jeddah; sealevel) underestimation at nighttime (Mecca and Jeddah)
The diurnal variation of the simulated and observed windspeed and direction are
very well correlated
Rainfall
Small scale: low magnitudes Large scale: Spatial patterns/magnitudes ~ OK
Model configuration RAMS version 4.4 , single grid Earth Simulator Model options used: grids δx, δy δt δz radiation land surface diffusion forcing forcing time scale convection land use soil
1 4 km (125x125) 10 sec 100 - 750 m (37) Harrington (‘96) LEAF-2 (Walko et al., ‘99) Mellor/Yamada (’82) ECMWF lateral 1800 s, centre 7200 sec Full microphysics package (Flatau, ’89) USGS (standard in RAMS 4.4) IGBP-DIS Soil properties database (Scholes et al.,2000)
3rd EU Japan meeting Jan 2005
Precipitation (19/04 – 26/04 2000)
Obs precip KM: 31.7 mm, G: 0mm
3rd EU Japan meeting Jan 2005
Greening run
Effect irrigated plantation on energy balance, local meteorology and precipitation Irrigated plantation z z z z
semi-desert ->shrubland approx. 36x90km (~27.8 103ha) 10mm/day irrigation gift
Greening run
Effect irrigated plantation on energy balance Ef raised from ~0.05 to ~0.9
Greening run
Effect irrigated plantation on energy balance z z
Ef raised from ~0.05 to ~0.9 Qn raised by 25%
Green
CTRL Qn λE H Qg
Greening run (1 week)
Sea breeze weaker/shorter for irr. plantation
coast/topo orthogonal
Greening run (1 week)
Diurnal moisture transport
r (g/kg)
Greening run (1 week)
Night-time fog formation
CTRL
GRN
RH %
Greening run (1 week)
Night-time fog formation
Greening run (1 week)
Night-time fog formation and rain
moisture convergence precipitation
Greening run (1 week)
Greening run (1 week)
Weekly rain difference
Greening run (1 week)
‘Efficiency’ irrigated plantation Irrigation gift 10 mm/day ~ Evaporation increase Precipitation increase
192 .106 m3 115 .106 m3 2.3 .106 m3 (34%)
Too much irrigation; could be reduced by 57% Only 1.2% recycled
3rd EU Japan meeting Jan 2005
Discussion
How real is all this? Known examples? Tentative conclusions Future work
3rd EU Japan meeting Jan 2005
Discussion known examples? TOPOGRAPHY
LANDCOVER
Puglia: “Capitanata: Irrigation scheme Courtesy F. Miglietta
rainfed crops
forest irr iga te d
grass cr
op s
Discussion known examples?
Fortore: 102500 ha Carapelle 30000ha Ofanto: 38000 ha Total: 170500 ha 396.106 m3 1 march - 30 nov ~0.75-0.85mm / day
Discussion known examples?
EFFECTS IRRIGATION on RAIN Irrigation operational since 1984 Summer rainfall increased 88% z
Difference 1960-1983 vs 1984-1992 • 5 plains stations vs 7 mountain stations • dP from 18 to 34 mm for July+August
3rd EU Japan meeting Jan 2005
Discussion Conclusions
RAMS – ES implementation successful Validation reasonable, good circulation (small + large scale!) Large scale irrigation does affect meteorology in South West Saudi Arabia z z z
Fog formation low intensity rain Sea breeze weakening Affects storm events ?
3rd EU Japan meeting Jan 2005
Discussion Future work
Better statistics: z z z
Year long run High/low monsoon intensity Climate change
Analysis existing cases
CONTINUED EU-JAPAN COLLABORATION!
3rd EU Japan meeting Jan 2005
Thank you
© Wageningen UR
3rd EU Japan meeting Jan 2005
