Variations in the total water storage in the major river basins of India from GRACE satellite gravity data

We present an estimate of total water storage variations of the major river basins of India during the period of 2002 to mid 2008 from modelling of time-variable gravity field observed by GRACE satellite by utilising the scheme of Swenson and Wahr, (2002). The largest annual volume change is observed over the upper Ganga basin, followed by the lower Gnaga basin and the Yamuna basin of northern India. Basins of northern India show a declining trend of water storage over this time period, whereas the Godavari basin, the largest basin of central south India, as well as basins in central India show similar seasonal variations but increasing trends. It is interesting to note that these trends are prevalent over a decadal time period of ground water level and therefore the trend observed from GRACE data can be extrapolated backward. If these trends are sustained over a long time period, northern India and Bangladesh will lead to a major water crisis