黄土裸坡降雨产流过程试验研究

Experimental Study of Runoff Processes on Bare Loess Hillslope

采用人工模拟降雨试验法对黄土裸坡降雨产流过程进行了研究.结果表明: (1) 坡面径流强度随降雨过程的变化可用对数相关方程进行描述,10～15 min是径流强度随降雨过程变化的转折点; (2) 坡度对坡面径流深的影响可用抛物线相关方程进行描述,25°左右是径流深随坡度变化的转折点; (3) 坡长对坡面径流深的影响可用对数相关方程进行表述,80 cm是径流深随坡长变化的转折点; (4) 雨强对径流深的影响可用线性相关方程进行描述,雨强与坡度2个因子共同作用时,坡度的作用几乎完全被雨强所掩盖; (5) 坡度、坡长及降雨强度对坡面径流深的综合影响可用多元线性相关方程进行描述,其中,降雨强度对坡面径流深的影响远大于坡长及坡度因子.

With artificial simulation rainfall tests, runoff processes on the bare loess slope are studied and the following results are obtained： （1） Runoff rate varied with rainfall course and could be described with logarithmic equations. Runoff rate didn＇t change until 10-15 min after rainfall began; （2） Slope gradient influenced runoff depth and could be described with parabola equations. The critical slope degree was about 25°, above which runoff rate changed its trend; （3） Generally runoff depth changed with slope length and their relations could be described with logarithmic equations and the critical length was 80 cm; （4） Rainfall intensity affected runoff depth much more greatly than slope gradient did and could be described with linear equations. The action of the latter was almost glossed over by that of the former; （5） The integrated impact of the three factors on runoff depth could be expressed using a plural linear function. Rainfall intensity showed much more influential on runoff depth than slope length and gradient.