Analysis of Runoff Generation under Different Canopies in Mountainous Slope

In order to examine the runoff generation processes in mountainous slope under Larix leptolepis (S1)and Abies holophylla (S4) two small plots were monitored. The rainfall and throughfall of both sites showed respectively a good correlations, whereas the quantity and intensity of throughfall in S4 exhibited larger than those in S1 and the mean lag time for throughfall generation from rainfall start in S4 was shorter than that in S1. The data of throughfall and runoff exhibited that the runoff discharge and runoff peak in S4 were smaller than those in S1, whereas the mean lag time for runoff generation from throughfall start in S4 was longer than that in S1. The total lag times from rain start to runoff generation of S1 and S4 showed similar, whereas each the lag time for throughfall and runoff generation exhibited different with sites. The results of this study suggest that the influences of different canopy species effects on throughfall characters and surface cover conditions, especially the lag time for throughfall and runoff generation, and which were distinctly reduced by the intensity increasing of rainfall and throughfall during the lag time.