坡度和前期土壤含水率是降雨产流过程的重要影响因素。为研究华北半干旱地区的降雨产流机制，本文采用人工模拟降雨的方法，进行了不同坡度（5°、10°和15°）和前期土壤含水率（0.20、0.25和0.30）条件下的降雨产流试验。结果表明：在整个降雨产流过程中，地表径流量随坡度和前期土壤含水率的增加而增大，累积径流量与产流历时呈线性函数关系；土壤入渗率和产流滞时均随前期土壤含水率和坡度的增加而减小，且前期土壤含水率对土壤入渗率和产流滞时的影响较坡度更加明显；Horton模型对降雨入渗关系的拟合结果优于Kostiakov 和Philip 模型。

Antecedent soil moisture content and slope gradient are significant influential factors for rainfall-runoff (RR) process. In order to study the RR mechanism of semi-arid region in the North China, artificial RR simulation test was carried out in the condition of different slope gradient and antecedent soil moisture content. According to the results: (1) In the whole RR process, the overland flow increased with the increase of antecedent soil moisture and slope, and the relationship between cumulative runoff and rainfall duration complied with a linear function. (2) Soil infiltration rate and runoff lag time decreased with the increase of antecedent soil moisture content and slope, and the influence of antecedent soil moisture on soil infiltration rate and runoff lag time was more obvious than that of slope. （3）Horton model was better than Kostiakov and Philip model in fitting the relationship between rainfall and infiltration.

中国水利水电科学研究院科研专项（1232）；国家自然科学基金项目（51209225;51409270）（National Natural Science Foundation of China（NSFC）（51209225;51409270））；国家国际科技合作专项（2013DFG70990）