金沙江中游沿江高速公路地质灾害差异性分布特征与成因机制

金沙江位于青藏高原东南缘,跨越我国第一、二地貌阶梯过渡带,流域内地质灾害频发。四川沿江高速是“一带一路”、“长江经济带”的重要支撑项目,对凉山州发展具有重大战略意义。针对金沙江中游沿江高速屏山-金阳段地质灾害的差异性分布这一特殊现象,本文通过遥感解译、实地调查和数据分析,对研究区地质灾害发育的背景条件与特征进行了系统梳理,分析了地质灾害差异性分布的成因机制,提出了研究区不同灾害类型的防治对策。研究表明:(1)沿江高速屏山-金阳段地质灾害表现为年降雨量大的屏山县泥石流灾害发育的比例远远低于年降雨量小的雷波县和金阳县;(2)地形地貌、地质构造以及地质构造与地震活动是差异性分布的内部影响因素;(3)临界降雨量和人类工程活动则是差异性分布的外部因素。内外因素共同主导着研究区内地质灾害的差异性分布。根据灾害类型的不同,给出针对的防治对策。

Study on the differential distribution characteristics and genetic mechanism of geological disasters, Riverside Expressway along the middle reaches of Jinsha River

Jinsha River is located in the southeastern margin of the Qinghai-Tibet Plateau, across the first and second geomorphic ladder transition zones in China, and geological disasters occur frequently in the basin. The Sichuan Riverside Expressway is an important supporting project for "The Belt and Road Initiative" and " Yangtze River Economic Belt " which is of great strategic significance to the development of Liangshan Yi Autonomous Prefecture. In view of the special phenomenon of the differential distribution of geological disasters in the Pingshan-Jinyang section of the high-speed along the middle reaches of the Jinsha River, this paper systematically sorts out the background conditions and characteristics of the development of geological disasters in the study area through remote sensing interpretation, field investigation and data analysis, analyzes the genetic mechanism of the differential distribution of geological disasters, and puts forward the prevention and control countermeasures of different disaster types in the study area. The results show that: (1) The geological disasters in the Pingshan-Jinyang section of the Riverside Expressway along the Jinsha River show that the proportion of debris flow disasters in Pingshan County with large annual rainfall is much lower than that in Leibo County and Jingyanghua3 County with small annual rainfall. (2) Topography, geological structure, geological structure and seismic activity are the internal influencing factors of differential distribution. (3) Critical rainfall and human engineering activities are the external factors of differential distribution. The internal and external factors jointly dominate the differential distribution of geological disasters in the study area. Corresponding prevention and control suggestions are put forward for different types of geological disasters.