Hydrogeological studies of springs in the catchment of the Gaula river, Kumaun lesser Himalaya, India

Abstract

The hydrological regime of the catchment area of Lesser Himalayan Gaula River in south-central Kumaun is seriously affected by the deforestation of hillslopes. This has caused accelerated erosion, particularly in areas of intense faulting and thrusting, and where human activities have induced drastic changes in the land-use pattern. Responses include the drying up of some springs and the reduced discharge of others. This has occurred in over 40% of the villages of the catchment area. Consequently, there is a decline in the flow of the main Gaula River; the discharge was reduced by 29.2% between 1951-1960 and 1961-1970, and by about 38.5% between 1971 and 1981. The diminished discharge of springs and streams may be attributed partly to lower rainfall receipts in several catchments - the decreases ranging from 9.7% to 76% between 1958 and 1986. Eight types of springs emanating from four categories of aquifers have been identified. The water yield of these aquifers varies greatly. Stream discharge, likewise, shows a strongly periodic annual rhythm, suggesting marked response to rainfall. This implies that only 24% of the rainwater recharges the groundwater that sustains steady year-round discharge of springs and streams.