岩溶地区红壤坡面入渗与坡面径流关系研究

Relationship Between Slope Infiltration and Slope Runoff in Karst Area

探究红壤坡面细沟侵蚀中入渗与坡面径流的关系,通过室内模拟冲刷试验,设计3种坡度(10°,15°,20°)和3种冲刷流量(0.7,1.0和1.3 L/min),测量不同时间段内的入渗量和径流量,探究红壤入渗与坡面径流的关系.结果表明,保持冲刷流量不变,在不同坡度下,坡面红壤入渗量会均随着时间的推移逐渐增大,坡度越小入渗量越大.随着时间增加,入渗量开始增加的幅度较大,之后慢慢减少,直至在某个数值左右波动.同时,坡度越高,坡面径流量就越大,不同坡度下坡面径流量随冲刷时间的推移会有不同的结果,存在一个使坡面径流量在30 min内随时间呈现稳定上升的临界坡度.保持坡度不变,在不同冲刷流量作用下,在冲刷前期确有着明显的规律,即冲刷流量越大入渗量越大,并且随时间的推移不断增大.同时,冲刷流量越大坡面径流量也就越大.在不同冲刷流量下,当坡面红壤饱和后入渗量会出现峰值.

We study the relationship between the infiltration and runoff in rill erosion of red soil slope.This paper designs 3 kinds of slopes(10 degrees,15 degrees,20 degrees)and 3 kinds of scouring flow(0.7 L/min,1.0 L/min,1.3 L/min)and uses indoor simulation erosion test to investigate the relationship between infiltration and runoff in different periods of time.The results show that keeping the capacity of scouring flow constant,the infiltration capacity of red soil on slope surface increases gradually with the increasing of time in different grade of slopes.With the increasing of time,the infiltration capacity begins to increase significantly and then reduces slowly until a certain value.At the same time,the higher the grade of slope,the greater the slope runoff capacity can be.There are different results of slope runoff capacity with the increasing of time and there also exists a critical slope which leads to slope runoff capacity increases steadily in 30 minutes.Keeping the grade of slope constant,there is a obvious law in the early stage of scouring.That is,the greater the capacity of scouring flow,the greater the flow rate can be with the increasing of time.Moreover,the greater the capacity of scouring flow,the greater the slope runoff capacity can be.The infiltration capacity appears the peak value when slope red soil is saturated in different capacity of scouring flow.