陕北露天矿排土场平台-边坡系统沟蚀演化与启动机制

North Shaanxi is one of energy-chemical industry base in China, in where coal mine mostly adopt the open mining. In the open pit, the runoff from the platform is large discharge and rapid afflux, which often results in serious gully erosion of dump slope. Because of the lag behind of gully erosion process of the platform-slope system, the ecological restoration and water and soil conservation design of dump were critically influenced. This project choose the platform-slope system as the research object, adopted research method of simulate rainfall and scouring experiment combined the 3D laser scanning technology and GIS system. Three different runoff patterns were set up in the rainfall and scouring experiment, which embody rainfall experiment (60 mm/min), scouring experiment (4 different level inflow) and superimposed experiment of rainfall and inflow. The objectives of this study are analyzing the special and temporal distribution of runoff -sediment characteristics, hydrodynamic parameters, and gully morphological characteristics, then comparing their differences among the three runoff patterns. At the same time, it will construct the visualization and digitalization system of erosion gully evolution. Then the relationship among gully morphological characteristics, runoff-sediment characteristics and hydrodynamic parameters under three runoff patterns and the hydrodynamic critical conditions of gully erosion can be achieved. Furthermore, the effect of gully morphological evolution on runoff-sediment relationship and the response of gully morphological evolution to hydrodynamic parameters will be elucidated. Finally，the hydrodynamics mechanism of the gully morphological evolution and gully erosion starting will be revealed. This research provides scientific basis for optimization design and ecological environment construction of open pit mine in arid and semi-arid area, which is of great scientific value.

陕北是我国重要的能源化工基地，区内煤矿主要为露天开采，产生的排土场平台径流汇集量大且急促，常导致边坡发生强烈沟蚀，严重时致边坡损毁或坍塌。但排土场平台-边坡系统在极端来水条件下沟蚀过程研究仍十分薄弱，严重制约矿区生态恢复与水保设计。以典型排土场平台-边坡系统为对象，采用野外模拟降雨、放水冲刷、降雨+放水冲刷试验、三维激光扫描和GIS技术分析相结合的方法。分析不同侵蚀动力下系统内水沙过程、水动力学参数、侵蚀沟形态演化的时空规律并比较其差异性特征，实现边坡侵蚀沟形态演化过程的图像化和数字化。建立不同侵蚀动力条件下侵蚀沟形态参数、水沙参数、水动力参数间关系，确定沟蚀发生的水动力临界条件，阐明不同侵蚀动力下侵蚀沟形态演化过程对水沙过程的影响和对水动力参数的响应，揭示平台汇水条件下平台-边坡系统沟蚀演化和启动的水动力机制。为我国露天矿排土场优化设计和生态环境建设提供科学依据，具有重要的科学意义。