Study On The Transport And Distribution Of Runoff Waters And Pollutants In The Runoff System With Backfilled Soil

Artificial rainfall experiment was used in this study to investigate distribution characteristics of runoff water and pollutants in the runoff system of the urban backfill soil with different slope?vegetation?rainfall intensity and rainfall time. The main results of this study are as follows:(1) Slope has a significant effect on runoff water and pollutants distribution.when the slope is 0°, district do not produce surface runoff.With the increase of slope,the proportion of runoff water and pollutants in surface runoff increased, but changed little.(2) Vegetation has a significant effect on runoff water and pollutants distribution. when the slope is 4°, vegetation district produced only svrface runoff,and three runoff types occurred in bare soil district. the proportion of runoff water and pollutants in vegetation district have a decline trend with increasing time,while the side-percolation flow have a rising trend. the proportion of runoff water and pollutants in bare district increased at the beginning, then reached the stable status with increasing time. the side-percolation flow and down-percolaton flow decresed at first, then reached the stable status.(3) Rainfall intensity has a significant effect on runoff water and pollutants distribution. when the rainfall intensity is small, the district only produces surface runoff, when the rainfall intensity is large, the district produces both surface runoff and side-percolation, the proportion of side-percolation flow will first increase and then decrease with the increase of rainfall intensity, Furthermore, surface runoff has been dominant.(4) Rainfall time has a significant effect on runoff water and pollutants distribution. With the increase of rainfall time, the proportion of runoff water and pollutants in surface runoff?side-percolation flow and down-percolation flow have a rising or decline trend.