Experimental Study on the Process of Runoff and Sediment Yield under Moving Rainfall
The spatial and temporal distribution of rainfall was an important factor influenced runoff and sediment yield.Based on the study about rainfall intensities and rainfall duration under the different moving rainfall directions,the relationship between runoff and sediment yield and its variation regularity was expected to be revealed.In this study,the indoor simulated moving rainfall experiments of 2 moving directions (up and down movement),2 rainfall intensities (1.35 mm/min,2.75 mm/min) and 2 rainfall durations (60 min,120 min) were carried out in order to analyze the runoff and sediment characteristics under different moving rainfall directions,intensities and durations.The results showed as follows:(1)For the moving upstream rainfall,with the same rainfall duration (rainfall intensity),initial runoff time of heavy rain (long rainfall duration) was 140 s (240 s),165 s (65 s) earlier than that of light rain (short rainfall duration).(2)For the moving downstream rainfall,the stronger rainfall intensity was and the shorter rainfall duration was,the steeper runoff and sediment yield curve was.The time of runoff and sediment arrived peak value was identical.(3)Compared with the moving upstream rainfall,the average time of initial rainfall runoff,runoff and sediment reached the peak lagged 2 210 s,2 468 s,2 948 s,respectively,in the moving downstream rainfall.The total of runoff and sediment yield reduced by 13.08％-74.90％ and 42.95％-84.24％,respectively,but the peak value of runoff and sediment were not obvious change rules.(4)The function expressions of cumulative runoff and sediment yield were different under different moving rainfall directions.
国家科技期刊平台
NSTL
万方数据
维普
