Experimental study of rill runoff processes on loess hillslope
TAN Zhen-Hua-;Wang-Tie-Li-;Tan-Xiao-;Liu-Dun-E-;Yuan-Yan-;Zhong-Han-Hui
1.State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and
Ministry of Water Resources,712100,Yangling,Shaanxi;2.Qinzhou Sub-station of Soil and Water Conservation Monitoring,535000,Qinzhou,Guangxi;3.State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau,Northwest A&F University,712100,Yangling,Shaanxi: China
Abstract:With multi-plot-based experiments of simulated rainfall and the addition of a steady in-flow at the top of the multi-plot system,the runoff processes of rill on loess hillslope are studied under five different rainfall intensities with same slope and five different slopes with same rainfall intensities.The main findings are as follows: 1) A power equation can be used to describe rill runoff rate changing with runoff process under different rainfall intensities.The overall trend for the three bigger rainfall intensities is a rise in the beginning and then goes to the relative stability,while it shows little change for the relatively smaller rainfall intensities with slightly rise later than the early.2) Changes in rill runoff rate with runoff process at different slopes behave in the same way as those under different rainfall intensities,with slightly rise later than the early,and also can be described by power equation.3) Rill runoff rate have the same trend of increasing firstly and stabilizing gradually with runoff processes under rainfall intensity and slope,but with the slope increase,the runoff rate increases more rapidly.4) Rill flow depth increases with rainfall intensity and slope,and logarithmic equation can be used for different rainfall intensities and different slopes,while a dual logarithmic equation,for the two factors.