Abstract: Five plots of land under different types of vegetation typical of the Napahai Catchment, i.e. grassland, pine forest, bare land, 3-year revegetated land and 1-year revegetated land, were selected, and soil water content, runoff, sediment, bulk density and organic carbon content therein measured for exploration of variation of soil water regime with vegetation and its influencing factors, which is of positive significance to the realization of protection of the local fragile ecological hydro-environment and sustainable development of the regional economy simultaneously. Results show that soil water content varied sharply with vegetation, and was 50.7%, the highest, in grassland, 34.5% in 3-year revegetated land, 28.7% in pine forest, and only 20% or so in bare land and 1-year revegetated land. The five plots of land did not differ much in soil physico-chemical properties, but did in surface runoff coefficient with grassland being the lowest, 1.21% only, and pine forest being 5.73%. Grassland and pine forest was lower than bare land and 1-year revegetated land in sediment yield. Soil water content was not significantly related with any soil physico-chemical properties and sediment yield, except for bulk density. Planting grasses may rapidly expand vegetation coverage of a land, which is an effective approach to rapid amelioration of the surface soil layer in physico-chemical properties, and strengthening the soil in water holding capacity.

Key words: Napahai, soil water content, vegetation restoration, runoff and sediment yield, Qinghai-Tibetan plateau