The Synthetic Effect of Rainfall Characteristics and Runoff From Upper Slope on Sediment Generation
Chen Hao (Institute of Geography, Chinese Academy of Sciences and State Planning Commission, Beijing, 100101)
Rainfall characteristic and runoff from upper slope are extremely important factors which influence the sediment generation at different geomorphic places in certain small watershed on the Loess Plateau. By analysing the test data from 26 times rainfall and runoff at different survey plots in Yangdao gully, it is found that the sediment generation(S)is in direct proportion to rainfall characteristic index(R_p)and the amount of runoff from upper slope(Q_L)and R_p·Q_L on sloping areas of ridge and hill while, on gully slope, the S increases with R_p, QL and R_p·Q_L on the one hand, on the other hand, it is in inverse proportion to Q_L~2. Meanwhile, the relation of S,R_p and Q_L could be expressed with a set of regressive equations.