官厅水库上游水土保持措施的减水减沙效益

采用北京延庆上辛庄径流试验站的裸地鱼鳞坑、侧柏鱼鳞坑、裸地水平条、板栗水平条、板栗树盘和休闲地坡面径流试验小区2001—2006年58次降雨的径流泥沙资料，分析北京山区官厅水库上游常用水土保持措施的减水减沙效益和水土保持措施因子值。研究结果表明：裸地鱼鳞坑、侧柏鱼鳞坑、裸地水平条、板栗水平条、板栗树盘的多年平均减水效益超过60％，减沙效益超过90％；鱼鳞坑、水平条和树盘的多年平均工程措施因子值分别为0．08、0．09和0．10，侧柏和板栗的多年平均生物措施因子值分别为0．41和0．48，且降雨量对水土保持措施的减水减沙效益以及水土保持措施因子值都存在明显影响。研究结果可为官厅水库上游地区．土壤侵蚀防治效益定量评价和水土资源管理提供重要参考。

Effect of soil conservation practice on runoff and sediment in upper reach of Guanting Reservoir

The benefits of runoff and sediment reduction and factor value for soil and water conservation measures were analyzed based on 58 rainfall events data(2001—2006) of fish pit(bare land),fish pit(Platycladus orientalis L.Franco),narrow terrace(bare land),narrow terrace(Castanea mollissima Blume) and tree pan(Castanea mollissima Blume).The results showed that the average benefits of runoff reduction of fish pit(bare land),fish pit(Platycladus orientalis L.Franco),narrow terrace(bare land),narrow terrace(Castanea mollissima Blume) and tree pan(Castanea mollissima Blume) were all more than 60%,and the corresponding annual benefits of sediment reduction were above 90%.The engineering measures factors for fish pit,narrow terrace and tree pan were 0.08,0.09 and 0.10,respectively.The biological measures factors for Platycladus orientalis L.Franco and Castanea mollissima Blume were 0.41 and 0.48,respectively.Rainfall amount had an important effect on benefit of runoff and sediment reduction and measures factors value.The results can be served as benefits evaluations of soil and water conservation and land resource management in upper reach of Guanting Reservoir.