短历时降雨强度对黄土坡地径流形成影响的实验研究

Experimental study on the effect of rain intensity on runoff formation over loess slope within short duration

雨强对坡地降雨径流形成过程有明显影响本文利用室内控制精度较高的实验设施，重复进行了黄土坡地降雨径流形成过程的实验，积累了较详尽的观测资料通过实验观测数据与数值模拟计算结果的比较，系统分析了短历时降雨强度对坡地入渗、坡面产流和坡面漫流过程的影响．阐明了短历时雨强对入渗的影响可分为两阶段：地表积水前雨强对入渗量及湿锋下移速率有明显影响；积水后影响甚小可忽略不计黄土坡地表层经常处于干燥状态，入渗能力大，而降雨历时较短，产流过程取决于雨强与入渗率的关系．短历时雨强对黄土坡面漫流的影响也可分为两阶段：部分面积汇流时雨强与坡面漫流量呈非线性关系。

Based on a lot of experiments on rainfall-runoff within short duration in laboratory, some characteristics and mechanism concerning the effects of rainfall intensity on the overland flow processes over the loess slope are illustrated. The phenomena are also simulated by a relevant mathematical model. The results from experiments and simulation of mathematical model show that the intensity plays an important rule in the process and relationship between rain intensity and peak flow is linear when flow comes from the whole area, where as, the relationship is nonlinear when it comes from partial area.