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Indian Water Resources – An Overview. Dr. K.V. Devi Prasad Embassy of India, Berlin. India -facts. Has many types of ecosystems – from deserts to tropical evergreen to alpine ecosystems Total area >3.3M sq. km. Population >1.1 billion Population is young and growing
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Indian Water Resources –An Overview Dr. K.V. Devi Prasad Embassy of India, Berlin
India -facts • Has many types of ecosystems – from deserts to tropical evergreen to alpine ecosystems • Total area >3.3M sq. km. • Population >1.1 billion • Population is young and growing => Demand for food and water increasing
India Projected growth • Economy expected grow rapidly • More than 7% p.a. in the last decade and a half • Population expected to grow to ~1.6 billion by 2050. • roughly 50% increase • Per capita growth rates are high
Indian Monsoon • The largest weather phenomenon in the world • Creates a distinct “rainy season” • The rainfall is asymmetrically distributed • Creates periods of excess and periods of shortage in water availability • Even the rainiest place on earth can have water shortage for a short period!!
Water – what the future holds! • Gross per capita water availability will decline from ~ 1820 m3 /yr in 2001 to ~ 1140 m3 /yr in 2050. • It was more than 5000 m3/yr in 1950!! • Total water requirement of the country for various activities around the year 2050 ~ 1450 k m3 /yr. • current estimate of utilizable water resource potential (1122 km3/yr)
The decline in water availability From Mall et al. 2006.
India – the land of Rivers • Rivers are the basis of everything • Rivers do not “drain” their catchments ; but they irrigate their deltas!! • Most food production depends on river water irrigation – especially peninsular India
Anticipated water requirements sectorwise [from Gupta & Deshpande, 2005]
What can be done? • Problem is complex and there can be no simple solution • Agriculture would still be the largest demand segment • Changes in Agriculture practice may help • Conventional rice farming requires ~1m per hectare per crop; Alternate wet & dry methods can save around 30%; SRI methods can save upto 50%
The way forward …. • Conservation and reuse of waste water • Most of non-agricultural use degrades the quality of water • Poses the double problems of waste and pollution • Conservation is key success • Another area would be augmenting sources
Ground water recharge • Rain water harvesting and ground water recharge are now recognised as important • Mandatory in some urban areas • 3 year deficient rainfall in Chennai in 2001,02 and 03 caused major problems • But it has downside • Water flow and sediment transport is important to oceans as well!!
Large dams??!! • Would dams impounding water help/ • Many criticisms of this approach • Interference to hydrogeology • Loss of biodiversity • Catastrophic failure • Sediment transport issues • Some deltas of the world are sinking!! • Rising seas and sinking deltas => human misery
Can we engineer on large scale • Some river basins have some water to spare • Can we transport water across the basins? • Costs? • Environmental consequences?