泾阳南塬黄土滑坡特征参数统计分析
Statistical analysis of the characteristic parameters of loess landslides at the South Jingyang Plateau
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摘要: 1976年泾阳南塬大面积提水灌溉以来,沿泾河右岸诱发了27处、50余起黄土层内滑坡,使得台塬面积不断缩小、水土流失加剧。本文在对南塬黄土滑坡特征参数测量的基础上,对其进行了统计分析,主要包括滑坡后壁陡坎高度、整体坡度、地裂缝发育情况以及滑距坡度等。分析表明:①滑坡后壁陡坎高度与马兰黄土厚度一致,受黄土垂直节理控制;后壁总体坡度较大,是黄土滑坡演化的重要因素;②裂缝发育规模总体偏小,但活动特征明显;③滑距坡度可作为研究区远程、短程滑坡划分的一种依据。同时,对滑距坡度在黄土滑坡滑距预测及危险性区划中的应用前景进行了探讨。Abstract: The South Jingyang Plateau is located in Shaanxi Province,China.Groundwater level in the loess plateau has been significantly raised since 1976 when the loess cover began to be artificially irrigated;more than 50 landslide events at 27 sites have occurred,which exacerbated the water and soil erosion and reduced the plateau area badly.Field survey and measurement of landslide characteristics were conducted at the South Jingyang Plateau,and the topographic features of the loess landslides,such as backscarp,cracks and angle of reach,were then statistically analyzed.The following conclusions can be reached: ① the upper vertical part at landslide backscarp was controlled by the thickness of the Malan loess(Q3) and the steep backscarp was an important aspect for loess landslide evolution in the study area;② the scale of cracks developed at the edge of loess plateau is small but indicated the high risk of loess landslide in the study area;③ the angle of reach is a suitable parameter for differentiating long-runout and short-runout landslides in the study area and has some application potentials in landslide runout forecast and hazard zoning.