GRACE and Water Loss from Indo-Ganga Basin

The Gravity Recovery and Climate Experiment (GRACE) uses satellite based estimates to assess depletion in groundwater from gravity anomalies. The GRACE technique attempts to quantify variations in Terrestrial Water Storage (TWS) which is the cumulative effect of components like groundwater, surface water, soil moisture, snow and ice, biomass apart from several other influences. Separation of groundwater from other components, therefore, need in situ observations and land surface/ hydrological modeling which is highly data dependent exercise. However, reliability of information derived on earth resources from any kind of remote sensing data depends on how best it tallies with ground reality. The sensitivity of satellite based gravity studies is quite high.