开发建设中扰动地面新增水土流失研究

针对神府东胜煤田开采过程中所引发的严重新增水土流失问题,采用野外放水冲刷的试验研究方法,对神府东胜煤田扰动地面新增水土流失机理和流失量进行了初步研究。结果表明:在相同放水冲刷流量和坡度下,原始地面的平均土壤入渗率较扰动地面的增加30%;两种不同类型下垫面的径流量均随时间的增加而增加,冲刷的前6min,径流量均较小,且原始地面>扰动地面,在6min以后,径流量迅速增大,且原始地面<扰动地面,扰动地面的平均径流量较原始地面增加14%;原始地面的侵蚀产沙在整个放水冲刷过程中没有显著变化,基本维持在一个常数水平;扰动地面在放水冲刷0—15min的侵蚀产沙量较高,此后侵蚀产沙随冲刷历时的延长而下降并最终趋于稳定;扰动地面的平均含沙量较原始地面增加96%,平均产沙量增加89%;新增土壤流失量随放水流量和坡度的增大而增大,10°时,新增土壤流失量最大;同一坡度条件下,放水流量越小,土壤流失量增加的百分比就越大,反之则越小。

Study on the Newly Occurred Soil and Water Loss on the Disturbed Lands in the Site of Development and Construction

Based on the severe newly occurred soil and water loss caused by the mining exploitation in the Shenfu-Dongsheng coal mining area,mechanism of newly occurred soil and water loss and soil loss tolerance were studied by using field water discharge scouring experiments.The results showed that the average water infiltration rate of original soil increased by 30% compared to disturbed soil surface under the same flow discharge and slope;runoff rate increased with time duration under the different surface conditions.About within 6 minutes before at the beginning of scouring,runoff rate was all little and the runoff rate in original soil surface was more than that in disturbed soil surface,after 6 minutes,runoff rate increased significantly,and the runoff rate in original soil surface was less than that in disturbed soil surface,the average runoff rate of disturbed soil surface increased by 14% compared to that in original soil surface;the sediment generation of original soil surface kept a constant level basically in the whole souring process,and obvious change of sediment yield was not observed.The sediment generation of disturbed soil surface was highest within 0—15 min,and then it decreased with time duration and tended to stable finally,the average sediment concentration increased by 96% and the average sediment yield increased by 89% compared to original soil surface;Newly occurred soil and water loss increased with flow discharge and slope increased and was the highest for slope with gradient of 10°.Under the same slope conditions,the percentages of soil loss increase were higher when flow discharge was smaller.