Variation of Sediment Concentration and Its Drivers Under Different Soil Management Systems  

作　　者：ZHANG Wen-Tai YU Dong-Sheng SHI Xue-Zheng TAN Man-Zhi LIU Liu-Song 

机构地区：[1]State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China) [2]College of Geography Sciences, Nanjing Normal University, Nanjing 210046 (China) [3]Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China)

出　　处：《Pedosphere》2010年第5期578-585,共8页土壤圈（英文版）

基　　金：Supported by the National Basic Research Program of China(No.2007CB407206);the National Natural Science Foundation of China(No.40621001);the Frontier Project of the Chinese Academy of Sciences(No.ISSASIP0715)

摘　　要：In order to prevent soil erosion in southern China,a study was performed to determine the drivers of sediment concentration variation using simulated rainfall and four soil management systems under field condition.Four soil management systems,i.e.,forest and grass coverage(FG),forest coverage with disturbed soil surface(FD),contour tillage(CT) and downslope tillage(DT),were exposed to two rainfall intensities(40 and 54 mm h-1) using a portable rainfall simulator.The drivers of sediment concentration variation were determined by the variations of runoff rate and sediment concentration as well as their relationships.The effects of the four soil management systems in preventing water and soil losses were compared using runoff rates and sediment concentrations at steady state.At runoff initial stage,sediment concentration variation was mainly driven by rainfall and management.The degree of sediment concentration variation driven by flow varied with different soil management systems.Three best relationships between runoff rate and sediment concentration were identified,i.e.,reciprocal(CT),quadratic(FG and FD) and exponential(DT).At steady state,runoff rates of the four soil management systems varied slightly,whereas their sediment concentrations varied greatly.FG and CT were recommended as the best soil management systems for preventing water and soil losses.In order to prevent soil erosion in southern China, a study was performed to determine the drivers of sediment concentration variation using simulated rainfall and four soil management systems under field condition. Four soil management systems, i.e., forest and grass coverage （FG）, forest coverage with disturbed soil surface （FD）, contour tillage （CT） and downslope tillage （DT）, were exposed to two rainfall intensities （40 and 54 mm h^-1） using a portable rainfall simulator. The drivers of sediment concentration variation were determined by the variations of runoff rate and sediment concentration as well as their relationships. The effects of the four soil management systems in preventing water and soil losses were compared using runoff rates and sediment concentrations at steady state. At runoff initial stage, sediment concentration variation was mainly driven by rainfall and management. The degree of sediment concentration variation driven by flow varied with different soil management systems. Three best relationships between runoff rate and sediment concentration were identified, i.e., reciprocal （CT}, quadratic （FG and FD） and exponential （DT）. At steady state, runoff rates of the four soil management systems varied slightly, whereas their sediment concentrations varied greatly. FG and CT were recommended as the best soil management systems for preventing water and soil losses.

关 键 词：runoff rate runoff steady state simulated rainfall soil erosion 

分 类 号：S157.1[农业科学—土壤学] TP311.13[农业科学—农业基础科学]