Remote Sensing Applications on the Indus Basin dr. Wim Bastiaanssen The Netherlands
Utilization of water resources River Basin Management Precipitation Consumptive Use Agriculture Irrigation Rainfed Other Evapotranspiration (ET) Non-Beneficial ET Beneficial ET Water-logged and Salinized Environment lands Forests Seepage areas Green Areas Reservoir water surfaces Lakes High water table areas Wetlands RIVER BASIN Outflow to the Sea Source: Doug Olson, WorldBank
What do we want? 1. Economic development? 2. Agricultural production and rural development? 3. Natural vegetation systems? 4. Environmental sustainability? 5. Reduce vulnerability to drought? Rank priorities! Baseline data should match with priorities
Remote sensing data Water use by agriculture and environment systems (incl. forests) Irrigated acreages Land cover Crop type Water logging Soil salinity Crop yield (income)
What do you want to see? 30 m 1000 m 250 m
Landsat mosaic Indus Basin
Developments Chasma Right Bank
Cropping intensity of irrigated land (Cen sus-remote sen sing)/census* 100% 200.0 100.0 0.0-100.0-200.0 kharif 1994 rabi 1993-94 1 3 5 7 9 11 13 15 17 32 19 46 21 23 25 27 29 33 35 37 45 39 41 42-300.0-400.0 ID command area 100% 200% (Sensus-remote sensing)/sensus * 100 % 60 40 20 0-20 -40-60 -80 AZ-IIIb AZ-IVa AZ-X AZ-IIIa AZ-II AZ-I Aggregated unit Kharif Rabi
Water consumption Indus Basin
Intercomparison with hydrological models Source: Ph.D. thesis dr. Sarwar Qureshi
ASTER, ETact, August 4, 2001
Soil moisture Indus Basin Source: IWMI, Lahore
ASTER, Soil moisture, August 4, 2001
Water balance, Rechna Doab - Pakistan
Net groundwater use, Pakistan I ngw (mm yr -1 ) -500-250 -100 0 +100 +300 +600 source: dr. Mobin-ud-Din Ahmad
Reliance of agriculture on groundwater
Wheat yield variability 1984-85
Wheat yield variability 2001-02
Impact of water on crop growth
Crop water productivity (kg/m3)
Waterlogging Chasma RB winter Waterlogging intensity (%) in Rabi 1 0 2 4 6 8 10 12 14 16 18 20 3 5 7 9 polygon no. 11 13 15 17 rabi 2000 rabi 2001 rabi 2002 19 21 23 25 27
Waterlogging Chasma RB summer Waterlogging intensity (%) in Kharif 0 2 4 6 8 10 12 14 16 18 20 1 3 5 45 25 7 9 polygon no. 11 13 15 17 19 kharif 1999 kharif 2001 kharif 2002 21 23 25 27
Soil salinity Egypt
Physical drought
Drought and vulnerability
Hydrological model - Sirsa
Simulation without remote sensing
Simulation with remote sensing
Nutshell Problems Indus Basin Inequity in canal water distribution Falling and rising groundwater tables Soil salinity build up Low crop water productivity Coping with droughts Good data is scarce Build a common databases
Remote sensing data streams 1. Baseline data I. Actual irrigated area (5 years) II. Crop occurrances (10 years) III. Digital Elevation Model IV. Traditional databases (soil map, canal command boundaries, water table etc.) 2. Process monitoring (weekly/monthly) I. Water consumption II. Crop growth III. Water logging IV. Soil salinity
Towards Indus Basin Environmental and Social Baseline Databases Remote sensing data provides key crop and water related data Satellite data is objective and freely accessible, distribution is easy Management targets should be prioritised Remote sensing data acquisition should meet water management objectives Scale issues should be decided upon (sample areas or entire Indus Basin?) Baseline and monitoring data need to be distinguished Remote sensing data can be coupled to Indus Basin model
Canal command area map
Soil map of Pakistan Soil Map of Indus Basin N W E S Types of Soils Calcareous Clayey Soils Calcareous Loamy Soils Calcareous Sandy Soils Calcareous Sandy Soils and Dun es Clayey Soils Gravely Land and Rock Land Gullied Land and Bad Land Loamy Soils Mountainous Land with Patchy Soil Cover Non Calcareous Clayey Soils Noncalcareous Loamy Soil Not Defined Open Water and Marsh Rough Broken Land Rough Mountainous Land Salt-affected Soils Sand Dunes and Sandy Soils Sandy Soils and Sand Dunes Seasonally Flo oded So ils and Rivers Silty and Clayey Soils Soils with very high Gypsiferous Salinity Tidal Flat and Sea Creeks 100 0 100 200 Kilometers
ASTER images
Net groundwater use P + I cw + NGW =ET a + S P =Precipitation I cw = Canal water NGW = Net groundwater use ET = Evapotranspiration S = Storage change I tw = Tubewell irrigation q (h m =0) = Recharge q (h m =0) = Capillary rise NGW = Tubewell irrigation + Capillary rise - Recharge
Water productivity and scale 6.0 Wheat (rabi 1993-94) Per unit consumed Per unit diverted Water productivity (kg/m3) 5.0 4.0 3.0 2.0 1.0 0.0 0 2 4 6 8 10 12 14 Cumulative Irrigated Area (million ha)