Soil and water conservation measures and their benefits in runoff and sediment reductions

Soil and water loss have been and are degrading the precious soil and water resources on which we have to rely. How to control over them has been being paid increasingly great attentions by the societies and scientists all over the world. Chinese people have got a long history of soil and water conservation practices and invented many sound measures for soil and water conservation, such as biological methods, tillage measures and engineering technologies. The main measures presently used are briefly discussed in the paper. Equations for modifications of slope gradient factor and slope length factor are used to convert the raw data of soil and water losses into those from standardized runoff plots for the purposes of calculating the runoff and sedimentation reduction percentages under different conservation practices. The data could be useful for watershed soil erosion prediction, rational implementation of soil and water conservation measures, as well as optimal utilization of lands.