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TRANSBOUNDARY WATER MANAGEMENTMap of 10 major river basins and seasonal variations in flow of selected rivers in the HKH regionDischarge [m 3 /s]50,00040,00030,00020,000Kabul atWarshakDischarge [m 3 /s]50,00040,00030,00020,000Indus atBesham QuilaDischarge [m 3 /s]50,00040,00030,00020,000Brahmaputraat Bahudarabad10,00010,00010,00001 2 3 4 5 6 7 8 9 101112Time [Month]01 2 3 4 5 6 7 8 9 101112Time [Month]01 2 3 4 5 6 7 8 9 101112Time [Month]AmudaryaTarimIndusGangesBrahmaputraSalweenYellow RiverYangtseDischarge [m 3 /s]50,00040,00030,00020,000Yangtze atHonkauIrrawadyMekong10,00001 2 3 4 5 6 7 8 9 101112Time [Month]Discharge [m 3 /s]50,00040,00030,00020,000Ganges atFarakkaDischarge [m 3 /s]50,00040,00030,00020,000Irrawadi atSagaingDischarge [m 3 /s]50,00040,00030,00020,000Mekong atKratao10,00010,00010,00001 2 3 4 5 6 7 8 9 101112Time [Month]01 2 3 4 5 6 7 8 9 101112Time [Month]01 2 3 4 5 6 7 8 9 101112Time [Month]Source: ICIMODthe peaks in water availability usually do not coincide with the highdemand periods. The eastern river basins depend mainly on monsoonprecipitation, while the western basins are dominated by westerlies andheavily reliant on meltwater. While the region is known for its abundanceof water resources, some areas are already water scarce, eitherphysically (with more than 75 per cent of river flows withdrawn foragriculture, industry and domestic purposes) or economically (meaningthat less than 25 per cent of water from rivers is withdrawn for humanpurposes, but significant improvements are needed in existing waterinfrastructure and management to make the water resources availablefor use). The western Himalayas and a large part of the Indus basinare recognized as physically water stressed areas. Large parts of theBrahmaputra, Ganges and Salween basins are categorizedas areas of economic water scarcity.Climate change and associated changes could havea serious impact on the stability of water supply in theregion. Observed warming in the region ranges from0.01 to 0.06° C per year. The Intergovernmental Panelon Climate Change (IPCC) has projected that temperatureswill be about 3° C warmer than the baseline bythe middle of the twenty-first century and about 4° Cwarmer by the end of the century. Models project about20 and 30 per cent increases in annual precipitation inthe eastern Himalayas, with increased interannual and[ 66 ]