野外人工模拟降水条件下荒草坡产流产沙试验

Sediment and yield runoff with simulated rainfall on a barren slope

采用人工模拟降水的方法,以5种不同的降水强度研究浙江省临安市青山湖流域内荒坡的产流产沙特征。结果表明,降水强度越大,产流时间越短,其径流量、产沙率和产沙量都越大,降水强度为1.66 mm·min-1时,产流时间仅为47 s,降水约30 min后,小区径流总量可达到0.898 m3,次侵蚀模数达到了30 t·km-2。降水强度与产流时间呈较好的负相关对数关系,与径流系数以及次侵蚀模数呈指数相关,与径流总量呈幂函数相关。相关系数分别达到了-0.965 5,0.921 8,0.963 5和0.873 6,均达到极显著水平(P<0.01)。

To assess sediment and yield runoff on a barren slope in the Qingshan Catchment of Lin＇an City, Zhejiang Province, a field , simulated rainfall experiment was carried out using five rainfall intensities （1.66, 1.57, 1.51, 0.97, 0.65 mm·min^-1）. Results showed that with an increase of rainfall intensity and a decrease in runoff time, runoff, ratio of sediment yield and sediment yield increased. When rainfall intensity was 1.66 mm·min^-1, the runoff time was 47 seconds, and after 30 minutes, runoff reached 0.898 m^3 with a soil erosion modulus of 30 t ·km^ -2. As a logarithmic function, rainfall intensity was negatively correlated with runoff time （r = - 0.965 5, P〈0.01）, while it increased with the exponential of the runoff correlation（r = 0.921 8, P〈0.01 ） and soil erosion modulus （r = 0.963 5, P〈0.01 ）. Also, with runoff as a power function, the correlation was r = 0.873 6（P〈0.01）. [Ch, 3 fig. 1 tab. 11 ref.]