基于图幅调查的六盘山镇孕灾地质条件分析

Analysis on Disaster-Pregnant Geological Environment of Liupanshan Town Based on Map Sheet Survey

调查研究小流域孕灾地质环境背景,是分析地质灾害时空分布规律与成灾模式,完成地质灾害易发程度、危险性区划评价,提出地质灾害综合防治对策建议的重要依据。以泾河流域六盘山镇幅地质灾害调查为实例分析了地形地貌、地质构造和工程地质岩组与地质灾害的关系。结果显示:(1)大的地貌单元和格局较明显地控制着地质灾害的分布,不同地貌单元内的地质灾害类型、发育程度和分布特征等都有差异性,统计表明滑坡主要发育在剥蚀构造丘陵区及低山区地貌,泥石流主要发育在侵蚀中低山区,崩塌主要分布在河谷斜坡地带和断裂带内,地质灾害一般沿地貌边界带密集分布发育,尤其是沿断裂呈线状展布;(2)软弱的泥岩岩组是研究区内主要的易滑地层,控制着地质灾害的分布,在不同工程地质岩组区间内滑坡面积的多寡与滑坡分布密度相关性不大;(3)区域地质构造不仅控制着区域地层的展布,也控制着区域地质灾害的发育,不同断裂也凸显出一定的差异性。

The investigation on small basin disaster-pregnant geological environment is an important basis to analyze the spatial and temporal distribution of geological disasters and disaster mode.It is also important to complete geological disaster-prone degree and zoning assessment of geological disasters and to propose comprehensive countermeasures.The geological hazard survey in Liupanshan Town of Jinghe River Basin analyzed the relationship between topography,geological structure,engineering geological rock group and geological disasters.The results show that：（1）the large landscape units and patterns obviously control the distribution of geological disasters,the geological disasters within the different types of landforms,the degree of development and distribution have some differences,the statistics shows that landslide mainly developes in the erosion construction hilly and low mountain areas,debris flow mainly developes in the low mountains,and collapse mainly developes in the valley slope zone and fault,the distribution of geological disasters developes densely along the border of general topography,linear distribution is common along the fault;（2）the weak mudstone rock group are the region′s major slide-prone stratum,controlling the distribution of geological disasters,the amount of the landslide has little correlation with landslide density in the range of different engineering geological rock group;（3）the regional geological structure not only controls the stratum spread,also controls the development of regional geological disasters.Different fracture highlights some differences.