7TANG Keli+1, ZHANG Keli 1,2 and LEI Aling 1,3 1. Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, China,2. Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China,3. Water Resources C.Critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau[J].Chinese Science Bulletin,1998,43(5):409-412. 被引量:16