Normally groundwater recharge is estimated using methods based on water balance, water table fluctuations, fixed factor of annual rainfall and tracer movement. In many of these methods water stored in the vadose zone and evapotranspiration are not accounted properly. These factors control groundwater recharge to a large extent, particularly in arid and semi-arid regions which are normally characterized by a deep water table, thick vadose zone and high evapotranspiration.

Water erosion caused by accelerated anthropogenic activities has been perceived as the major source of sediment flow in Himalayan catchments. Keeping this in view, the sediment flux data measured at the outlet
of the Sainj and the Tirthan watersheds in the Lesser Himalayan region was analysed.