Forest hydrological studies in different agro-climatic conditions in India

Forests are essential to both development and preservation of global environment. A review of the results on runoff, peak discharge and soil loss from small forest watersheds in various agro-climatic regions of the country has been attempted. Based on various studies conducted in India, it appears that in small watersheds, forest tend to decrease the surface runoff and peak discharge. Contrary to this, in larger watershed, the surface runoff component of total water yield gets increased. Soil loss was observed less from dense and well managed forests in comparison to ill managed (denuded) forests. However, soil loss is observed even lesser than forest from well managed grassland. Soil conservation measures are found effective in reducing the runoff and soil loss. Hydrological research on small forest watersheds carried out in various regions is scattered and scanty for up-scaling to predict hydrological responses on large heterogeneous watersheds and land-uses. Hydrological investigations on different forest species/cover, topographic, physiographic, climatic and edaphic conditions employing uniform methodology and instrumentation are required. Most of this work need to be of an inter-disciplinary nature and should take full advantage of locally available environmental knowledge.