地形因子对矿山泥石流发育的影响

Influence of topographic factors on debris flow development in mines

矿山泥石流地质灾害的发生需要特定的条件,在同一区域,相同物源供给和降雨条件下,地形因子控制着泥石流的发生、发展及其危险程度。由于地形展布的复杂性和不规则性,为了定量评价地形因子对矿山泥石流发育的影响,以陕西凤县34条泥石流沟为研究对象,分别选取汇水面积、沟道比降、沟道长度等关键参数,利用分形理论计算其分维值。结果表明,研究区内泥石流沟的汇水面积、沟道比降、沟道长度均存在明显的分形特征,其分维值分别为0.63、1.08、0.96。通过与5个典型地区自然泥石流沟、3个典型矿山泥石流沟进行对比分析。结果表明:研究区矿山泥石流沟形态与自然泥石流沟形态具有相似性,即均受汇水面积的影响显著,而其分维值与典型矿山泥石流沟的分维值总体变化趋势一致。研究区的矿山泥石流沟具有汇水面积少、沟谷尺度小、沟道比降陡的特点。

The occurrence of mine debris flow geological disaster needs specific conditions.In the same area,the same material supply and rainfall conditions,the terrain factors control the occurrence,development and risk degree of debris flow.Due to the complexity and irregularity of terrain distribution,in order to evaluate the influence of terrain factors on the development of mine debris flow quantitatively,34 debris flow gullies in Fengxian County,Shaanxi Province are selected as the research objects,and the key parameters such as catchment area,gradient of gullies and length of gullies are selected respectively,and the fractal dimension value is calculated by using fractal theory.The results show that there are obvious fractal characteristics in the catchment area,channel gradient and channel length of debris flow gully in the study area,and the fractal dimension values are 0.63,1.08 and 0.96 respectively.Through the comparison and analysis with 5 typical natural debris flow gullies and 3 typical mine debris flow gullies.The results show that the shape of mine debris flow gully in the study area is similar to that of natural debris flow gully,i.e.it is significantly affected by catchment area,and its fractal dimension value is consistent with that of typical mine debris flow gully.The debris flow gully in the study area has the characteristics of small catchment area,small gully scale and steep gully gradient.