Research on the processes of rainfall,surface runoff and sediment on sloping field with red loam by simulated rainfall experiment

In this research,the process experiments of runoff and sediment yield under different rainfall intensities were conducted with different red loam slopes by artificial simulated rainfall ways,at soil and water conservation station in the Lanxi city of Zhejiang province.The testing runoff plot were designed with the slope of 8°,15°,20°,the vegetation cover degree of 15%,rainfall intensity of 0.8～2.9 mm·min-1 ,and the area of 2 m 2 .The change characteristics of runoff and sediment yield were mainly analyzed on the basis of simulated rainfall of 32 sets.Some conclusions were obtained and listed as follows:①The relationship betweensediment and rainfall intensity is exponential function,runoff and rainfall intensity is power function.The relativity between runoff and sediment is better than rainfall intensity and runoff,rainfall intensity and sediment.②As slope increases,the time for runoff occurrence has been moved up,and the critical rainfall intensity for sediment start moving and abruptly increasing are reduced.③As slope increases,the increasing rate of accumulative sediment is faster than that of accumulative runoff.④As slope increases,the relativity between erosion modulus and rainfall intensity heightens.