Impact of population growth and climate change on the quantity and quality of water resources in the northeast of India

The northeastern region of India is extremely rich in water resources but a continuous increase in human interference and mismanagement has rendered these resources in a fragile state. The region receives about 510 km(3) of water as annual rainfall. It has two major river basins, the Brahmaputra and Barak, which drain 194 413 and 78 150 km(2), with an annual runoff of 537.0 and 59.8 km(3), respectively. The prevalence of shifting cultivation has resulted in deforestation and soil loss, causing silting of riverbeds and frequent occurrence of floods. Due to population pressure, more and more forest area is being cultivated, putting the whole ecology in peril. The declining trend in rainfall and frequent temperature fluctuations are a signal of climate change. The demand for water for domestic use has suddenly increased due to the rapid population growth and a change in the life style of the people. Water demand is high and the supply is not commensurate with it. Due to mismanagement of rainwater, about 3.586 x 10(6) ha of land has become prone to flooding. Further, water quality has also deteriorated due to its pollution by nitrates, chlorides and sulphates, and increased use of fertilizers and pesticides in an effort to increase crop productivity in the region. If the rate of population increase remains unabated, the water resources are likely to dwindle further and the quality of water is likely to deteriorate as well.