Overland flow and soil movement from forests in Kumaun Himalaya

Abstract

Overland flow and soil movement were measured on small plots of three forest types in the Kumaun Himalaya. Average seasonal (June through September) overland flow (measured over 2 years) was 0.49% of the seasonal rainfall (1967 mm) and was always less than 1% of each rain event (there was less than 0.1% difference among forest types). Seasonal soil movement ranged from 2.3 to 3.2 g·m⁻² among forest types and averaged 2.6 g·m⁻². Both overland flow and soil movement were significantly different between months, being positively correlated with amount of rainfall. Sediment concentration of runoff water did not vary among months by more than 0.1 g·L⁻¹. The study indicates that steep, forested slopes are not an important sediment source in Kumaun Himalaya.