设计了一种简单的壤中流观测系统来研究不同降雨产流事件的过程。结果表明：（1）在小雨时，只有表面径流发生；而且，当雨前土壤较干燥，降雨初期强陡然增大的情况下，表面产流峰有特别明显滞后现象，这是由于临时相对不水表层形成之故。（2）在暴雨和大暴雨时，表面径流和壤中流都有发生；壤中流比表面径流滞后更明显；壤中流在雨后的产流历时与降雨无关；在大暴雨时，耕作层的壤中流水位过程曲线与表面径流相似，说明耕作层的大孔隙和管流明显。（3）在小雨和暴雨时，表面流由超渗产流机制形成；在大暴雨时，表面流主要由饱和超渗产流机制形成，只有少部分回归流；（4）表面径流的数值模拟能揭示表面产流的一般趋势，而且有一定的有效性，通过调整模拟参数，能使模拟效果更佳。

A throughflow collection system is established to investigate the process of runoff generation both for surface flow and subsurface flow. The results show that: 1. under the condition of flurry, surface runoff will be generated and the lag phenomenon may happen to the flow peak if the soil is dry before the rain; 2. both surface runoff and throughflow commence under the condition of rainstorm and down-pour; 3. under the condition of flurry and rainstorm, surface runoff is controlled primarily by infiltration-excess runoff mechanism. The numerical simulation can be used to explore the general tendency of the surface runoff.