Abstract:

A scouring experiment was carried out to investigate the effects of discharge flow(5,10,15,20 L·min^-1)on the processes of runoff and sediment yielding with different plantation rehabitation methods (drilling Astragalus adsurgens Pall; broadcasting Salix cheilophila and Astragalus adsurgens Pall; broadcasting Astragalus adsurgens Pall; broadcasting Melilotus suaveolens Ledeb; broadcasting Medicago sativa) in Yongli open pit mine, Inner Mongolia. Results showed that the average infiltration rate of side slope with plantation was 7.55%~192.19% higher than the bare land. The runoff volume with plantation was 0.97%~90.49% lower than the bare land. The water reducing benefit of Medicago sativa was the best under the flow of 20 L·min^-1, and at other flow rates, the water reducing benefit of Astragalus adsurgens Pall was the best. The runoff volume was found to be a power function of discharge flow. The sediment yield with plantation was 63.45%~93.27% lower than the bare land. The sediment reducing benefit of Astragalus adsurgens Pall was better than Medicago sativa. The sediment yield was found to be a power function of discharge flow. Results can provide scientific guidance for vegetation measures of dump side slope protection in wind-water erosion region.

Key words: Open pit mine, Side slope of dump, Vegetation restoration, Flow discharges, Runoff and sediment reduction

摘要：

以内蒙古准格尔旗永利露天煤矿排土场边坡为研究对象，采用野外放水冲刷的试验方法，研究不同放水流量下（5，10，15，20 L·min^-1）沙打旺（Astragalus adsurgens Pall）条播、沙柳（Salix cheilophila）方格+沙打旺撒播、沙打旺撒播、草木樨（Melilotus suaveolens Ledeb）撒播和紫花苜蓿（Medicago sativa）撒播等植被措施对边坡径流产沙的影响。结果表明：植被措施坡面入渗率较裸地增大7.55%~192.19%，沙打旺条播和沙柳+沙打旺撒播的入渗率随放水流量的增加而增大，而裸地、沙打旺撒播、草木樨撒播、紫花苜蓿撒播入渗率随着放水流量的增加先增大后减小再增大。植被措施坡面的径流量较裸地减少0.97%~90.49%。放水流量为5~15 L·min^-1时，沙打旺减水效果最好，流量为20 L·min^-1时，撒播紫花苜蓿减水效益最高。各植被措施的径流量与放水流量均呈显著的幂函数关系。植被措施坡面的产沙量较裸地减小63.45%~93.27%，撒播紫花苜蓿的减沙效果最佳，条播沙打旺次之。各植被措施的产沙量与放水流量均呈显著幂函数关系。结果可为风蚀水蚀交错区露天煤矿排土场边坡植被防护措施的优化配置提供科学指导。

关键词: 露天煤矿, 排土场边坡, 植被恢复, 放水流量, 减水减沙