太湖流域平原水文试验区降雨产流过程特征研究

为研究太湖流域平原地区降雨产流特征，选取金坛水文试验区开展降雨产流过程观测，提取影响次降雨产流的特征要素，剖析典型蓄满、超渗产流案例中的产汇流过程。结果表明：试验区以蓄满产流机制为主，超渗产流现象较少。长历时小雨强条件下试验区产流过程可分为补给土壤水、填洼和排水沟出流、全面出流、雨止消退4个阶段。排水沟出流阶段径流系数小，以排水沟面积承接雨水出流为主；全面出流阶段为蓄满条件下的超渗产流，雨强阈值约0.1mm/min，径流系数大。前两个产流阶段在短历时强降雨中同时发生。若全面出流阶段土壤尚未蓄满，则仍有较大比例雨水入渗，属传统意义上的超渗产流；若土壤已蓄满，则为蓄满条件下的超渗产流。

Study on characteristics of rainfall-runoff generation processes at a plain experimental area in Taihu Lake Basin

To study the characteristics of rainfall-runoff generation processes in the plain area of the Taihu Lake Basin, the Jintan hydrological experimental area was selected to carry out the observation of rainfall-runoff processes.The specific elements that affected the runoff generation during rainfall events were extracted and the whole hydrologic processes of two typical runoff generation events, which were dominated by saturation-excess and infiltration-excess mechanism respectively, were analyzed. The results indicate that the experimental area is dominated by the mechanism of saturation-excess and the phenomenon of infiltration-excess is rare. The runoff generation processes in the plain experimental area under the condition of long-duration light rainfall can be divided into four stages: soil water filling, surface depression filling & ditch outflow, whole area outflow, and recession after rainfall. The runoff coefficient in the ditch outflow stage is small and the outflow is mainly composed of the rainwater falling on the area of the ditch. The whole area outflow stage belongs to the infiltration-excess mechanism under the condition of soil moisture reservoir is saturated and the rainfall intensity threshold is about 0.1mm/min with a large runoff coefficient. The first two runoff-generation stages may occur simultaneously in the short-duration heavy rainfall. If the soil is not saturated at the whole area outflow stage, it is a traditional infiltration-excess dominated runoff event with a large proportion of infiltration. While if the soil is saturated, it belongs to the infiltration-excess mechanism under the condition of soil moisture reservoir is saturated.