构造作用对地质灾害分布的影响分析——以四川省马边县地质灾害为例

Influence of Tectonic Activities on the Distribution of Geological Hazards——A Case Study of Mabian County, Sichuan Province

地质构造作用对地质灾害的发育和分布具有重要的影响。为降低地质灾害对人民生命财产的损失和对环境的破坏,提高马边县地质灾害的防灾减灾能力,通过野外调查、区域地质分析、数据统计和GIS空间分析等方法,运用定性和定量结合法研究了四川省马边县地质灾害的分布与构造地貌、构造地质2大因素,以及与坡度、坡向、地形起伏度、坡型、地层、断层(含褶皱)、地震和水系等8小类因素的关系。结果表明:(1)地质灾害类型上以崩、塌、流、不稳定斜坡为主,规模上以中小型为主,在区域空间上分布具有不均匀性;(2)构造地貌因子敏感区间为:坡度:20°~30°,地形起伏度:≥60 m/km2,坡型:凸型坡为主,坡向:对灾害分布敏感性不强,在每个坡向灾害分布较均匀;(3)构造地质因子敏感区间为:地层:泥岩和砂岩为主的软弱-半坚硬岩组的侏罗系和白垩系为主,断层(含褶皱):距断层0~0.5 km为主,地震:距震中0~1 km为主,水系:距河道0~0.5 km为主。该研究可为马边县地质灾害的预防和治理提供科学依据。

Geological tectonic activities exert an important impact on the development and distribution of geological disasters.This work aims to reduce the loss of human lives and property and environmental damage, and to improve the disaster prevention and mitigation in Mabian County of Sichuan Province.On the basis of field survey, regional geology analysis, data statistics and GIS spatial analysis, this study utilized qualitative and quantitative methods to discuss the relationship of geological disaster distribution with topography, geological structures, and slope, aspect, relief, slope, stratum, river systems, faults, earthquake.Results show that(1)the geological disasters are dominated by landslides, collapses, flows, and unstable slopes, and are mainly small-and medium-sized, with uneven distribution in regional space;(2)the sensitive intervals of structural geomorphological factors are as follows.The slope is 20°~30°,the topographic undulation is ≥60 m/km~2,and the slope is mainly convex.The aspect is not sensitive to disaster distribution, and the disaster distribution in each aspect is relatively low-uniform;(3)the tectonic factor sensitive intervals are in the following.The strata are dominated by the Jurassic and Cretaceous weak-semi-hard rock dominated by mudstone and sandstone, and the faults(including folds)are dominated by the distance of 0~0.5 km.The earthquakes are mainly 0~1 km from the epicenter, and the water system is mainly 0~0.5 km from the river.The research can provide a scientific basis for the prevention and management of geological disasters in Mabian County.