芦山县滑坡灾害影响因素的空间分异性

近年来受多次地震影响,芦山县的地质环境和生态结构较为脆弱,滑坡灾害高发,制约了县内基础建设和经济发展,威胁着人民生命财产安全,研究静态地质环境下芦山县滑坡影响因素的空间分异性,可为区内国土空间规划提供基础资料,为滑坡灾害预测与防治提供数据支持。本文使用信息量模型和地理探测器分析了高程、坡度等12个影响因素与滑坡发育的关系,总结了滑坡发育规律,分析了影响因素的空间分异特征,并使用GIS加权叠加生成了滑坡易发性评价图。研究结果表明: ①滑坡主要集中于高程较低(571,1 300) m)、距道路距离较近(0,300) m)、距水系距离较近(0,300) m)、地形起伏度较小(0,30) m)、坡度较缓(0°,30°))、距断层距离较近(0,600) m)的地区,岩土类型以粉砂质泥岩、泥质粉砂岩、泥岩等软弱沉积岩和砂卵砾石土层的第四系堆积物为主,土地利用类型以建设用地、农业用地等为主; ②滑坡发育主要受高程、距道路距离、工程地质岩组等因素控制,此外土地利用类型、距水系距离、地形起伏度、坡度、距断层距离等因素也有较高的贡献率; ③两种不同影响因素对滑坡发育的作用较单一因素而言均呈现双因子或非线性增强,以高程和距道路距离与其他因素的交互作用最为强烈; ④滑坡高易发区和极高易发区主要分布于东南部中低山峡谷区、丘陵区以及河流沟谷地貌。

Spatial heterogeneity of influencing factors of landslide disasters in Lushan County

The geological environment and ecological structure are relatively fragile in Lushan County due to the frequent earthquakes in recent years. The high-frequency landslide disasters restrict the infrastructure construction, economic development, and threaten the safety of people’s lives and properties. The analysis of spatial hete-rogeneity of influencing factors of landslide disasters in Lushan County under static geological environment can provide basic data for land and space planning in the region and data support for landslide disasters prediction and prevention. The relationship between landslide development and 12 influencing factors, such as elevation and slope, were analyzed by information model and geographic detector, and the law of landslide development were summarized. Besides, the spatial heterogeneity characteristics of influencing factors were also studied, and a landslide-prone Sexual Evaluation Chart was generated using GIS weighted superposition. The results show that ① Landslides are mainly concentrated in areas with low elevations (571,1 300) m), close to the road (0,300) m) and water system (0,300) m), small topographic relief (0,30) m), gentle slope (0°,30°)) and close to fault (0,600) m). The landslides occurred in sedimentary rocks of silty mudstone, argillaceous siltstone, mudstone and Quaternary sedimentary, and lands for construction and agriculture. ② Landslide development is mainly controlled by factors such as elevation, distance from road and engineering geological rock group. And the land use type, distance from water system, terrain relief, slope, and distance from fault also have high contribution rates to the landslide. ③ The effects of two different influencing factors on landslide development show two-factors or nonlinear character compared with a single factor. The interaction between the distance from the road, elevation and other factors is the strongest. ④ The landslide-prone areas and extremely high landslide-prone areas are mainly distributed in the middle and low mountain canyons, hilly areas and river valley landforms in the southeastern areas.