凉山州山地灾害空间分布特征及人为驱动力分析

Analysis on the Spatial Distribution Characteristics and Human Driving Forces of Mountain Hazards in Liangshan Prefecture

基于凉山州1970—2004年间的山地灾害数据,采用GIS空间网格分析等方法,分析凉山州山地灾害的分布特征,进行了危险度评价,并划分了研究区山地灾害危险度等级。结果显示:凉山州山地灾害多沿水系呈带状分布,其中以中部安宁河流域和东北部地区较集中,山地灾害极高频区面积3 080.6km2,占州总面积比为5.0%,高频区占8.0%,中频区占14.1%,低频区占72.9%。通过山地灾害与人为驱动力(人口、土地利用类型等)的相关性分析,获得其间的响应关系。分析表明:一方面山地灾害危险度与人口密度分布显著正相关,另一方面不合理的土地利用结构也是山地灾害的重要驱动力,特别是旱地(坡耕地)和交通建设用地影响较大。研究结果对人为活动引起的山地灾害防范、县域山地灾害危险度划分和山地灾害风险管理等具有一定的指导意义。

Based on the data of mountain hazards from 1970 to 2004, GIS spatial grid analysis was used to ana- lyze the spatial distribution characteristics of mountain hazards in Liangshan Prefecture, which is located in southwestern Sichuan, evaluate mountain hazards risk and divide risk levels. The results showed that most mountain hazards were expressed by the zonation along the river, mainly in Anning River Basin and Jinsha River Basin. According to the occurrence frequency of disasters, Liangshan Prefecture was classified into four regions： the very high frequency region, high frequency region, moderate frequency region and low fre- quency region, which account for 5.0%, 8.0%, 14.1%0 and 72.9% of total area, respectively. By analyzing the correlation between mountain hazards and human driving forces （economic, demographic characteristics and land-use type etc. ）, the response relationship between them was obtained. According to the correlation analysis, it can be seen that the mountain disaster risk and the population density had a significant positive correlation. What＇s more, unreasonable land use was another important driving force on mountain hazards, especially dry lands （sloping lands） as well as transportation lands. These results will play an important role in preventing and mitigating mountain hazards caused by human activities, and the method used in this study will play guiding role in mountain hazard risk assessment and management.