干旱区生态环境知识资源中心

A good understanding of the erosion rate and sediment source is an important prerequisite for the soil and water conservation, and the prevention and reduction of flood hazard. The objectives of this study are to estimate the erosion rate under different land uses and the sediment source by the Cs-137 tracing method in a watershed on the Loess Plateau of China. In the study watershed, 54 sampling sites were selected from five land use types. The results showed that the average erosion rate from the bare land, cultivated land, desert, woodland and grassland was 6500, 5900, 4850, 620 and 320 t/km(2).a, respectively. Combining the area of various land uses in the watershed, the percentage of sediment yields from the bare land, desert, cultivated land, woodland and grassland was 48.0, 28.6, 19.3, 2.1 and 2.0 %, respectively. The bare land, desert and cultivated land are the main sediment sources. These findings will be useful for the soil and water conservation management and the planning of mitigation measures.