基于GIS和信息量模型的陇川县滑坡易发性评价

云南省陇川县地质环境脆弱,易发生滑坡灾害,对其开展滑坡易发性评价对指导陇川县的滑坡地质灾害防治具有重大意义。根据陇川县地理环境、地质环境、人类活动等条件,选取高程、坡度、坡向、剖面曲率、平面曲率、归一化植被指数、水系距离、断层距离、地层岩性和道路距离等10个评价因子,利用信息量模型和ArcGIS软件进行滑坡易发性评价。结果表明,滑坡高易发区主要位于研究区北部、东南部和西南部;中易发区主要位于中部、东部和西部部分地区;低易发区主要位于陇把镇、城子镇大部分地区和户撒阿昌族乡的西北部;不易发区主要位于清平乡中部、城子镇中部部分地区、以及章凤镇大部分地区。在中易发区和高易发区包含83.56%的滑坡灾害点,且滑坡面积随着易发性等级的增加也随之增大。滑坡中、高易发区内发生的滑坡面积分别占研究区滑坡面积的22.79%和58.13%,分析结果与实际灾害分布特征相吻合,可为研究区及类似区域的滑坡地质灾害防灾减灾工作提供参考意见。

Landslide Susceptibility Assessment of Longchuan County Based on GIS and Information Value Model

The geological environment of Longchuan County,Yunnan Province,is fragile and vulnerable to landslides.Analyzing the susceptibility of regional landslide hazards is of great significance to prevent and control the landslides in this area.Ten evaluation factors are established.They are elevation,slope,slope direction,section curvature,plane curvature,normalized vegetation index,distance from water system,fault distance,lithology and road distance.Landslide susceptibility evaluation is assessed by using information value model and Geographic Information System(GIS).The results show that the high landslide susceptibility zones are mainly located in the north,southeast and southwest of the study area;the moderate landslide susceptibility zones are mainly in the central,eastern and western parts of the study area;the low landslide susceptibility zones are mainly in Longba Township,most of Chengzizhen and northwest of Hu Sa Achang;the extremely low landslide susceptibility zones are mainly located in the central and urban areas of Qingping,part of the central part of Chenzi and most of Zhangfeng.83.56%of the landslide hazards are in the middle and high susceptible zones,and the area of landslide increases with the increase of the susceptibility grade.The area of the middle and the high landslides susceptible zones accounts for 22.79%and 58.13%respectively of the total study area.The results are consistent with the actual distribution of landslide hazards,which can provide theoretical reference for disaster prevention and mitigation in the study area.