矿渣堆积对小流域行洪能力影响的数值模拟研究

Numerical simulation of slag heap effects on flood capacity in small catchment

矿山开采过程中废弃矿渣堆积对流域水文过程有着一定的影响作用。建立了基于水动力方法的二维雨洪过程数值模型,分析5种不同重现期暴雨下矿渣堆积引起的地形改变对于大西岔流域行洪能力的影响。研究发现:矿渣堆积对于流域出口断面具有一定滞洪效果;5种不同降雨重现期中,10年一遇降雨时洪峰削减效果最为显著,当降雨重现期小于10年一遇时,地形对洪峰大小、到达时间起主要影响作用,反之,降雨成为主要影响因素;洪峰削减率随着断面向下游移动而逐渐增大。研究成果对于降低矿渣堆积流域下游洪水风险具有一定积极意义。

The waste slag heap of mining could exert considerable effects on the hydrological process of a catchment. In this paper, a 2D numerical model of rainfall -runoff process based on a hydrodynamic ap- proach was established to investigate the effects of the terrain change as a result of the slag heap on flood capacity in the Daxicha drainage basin, under the design storms with 5 different return periods. It is found that： the slag heap is able to attenuate the flood peak at the export sections. In the return period of five different types of rainfall, the storm with 10 - year return period causes the most significant attenua- tion for flood peak, while for the storm with the return period less than 10 years, the terrain plays a more important role for the flood peak value and the arrival time, on the contrary, rainfall has become a major factor. The attenuation rate of the flood peak will increase as the section moves downstream. The research could help mitigate the flood risk in the flood plain downstream of the catchment with slag heaps.