河北省顺平县地质灾害发育特征及易发性评价

Characteristics and susceptibility evaluation of geohazard development in Shunping county,Hebei province

河北省顺平县位于太行山东麓,主要发育有崩塌、滑坡、泥石流、地裂缝等四种类型地质灾害。基于该县地质灾害发育特征,采用GIS技术和信息量数学评价模型,选取坡度、起伏度、坡向、工程地质岩组、归一化植被指数(NDVI)、与河流的距离6个评价因子,对顺平县地质灾害进行易发性评价。评价结果显示:高易发区面积约为125 km^2,占全县总面积的17.5%,分散分布于西北部的中低山和丘陵地区,密集发育崩塌灾害,少量发育滑坡、泥石流灾害;中易发区面积约为200 km^2,占全县总面积的28.0%,成片分布于西北部的中低山和丘陵地区,少量发育崩塌、滑坡、泥石流灾害;低易发区面积约为389 km^2,占全县总面积的54.5%,主要分布于东南部的平原地区及西北部丘陵地区内的宽阔沟谷,沿古河道发育地裂缝灾害,个别地区发育崩塌、滑坡灾害。

Shunping county of Hebei province is located at the eastern foot of the Taihang Mountains.There mainly are four kinds of geohazards,including rockfall,landslide,mud-rock flow,and earth fissures,which are widely distributed in different geomorphic units of this county.Based on the analysis of geohazard development characteristic’s,this paper selects six factors,namely slope angle,level differenc^e,slope direction,engineering geological rock group,normalized differential vegetation index(NDVI),and distance to rivers,to evaluate the susceptibility of geohazards in Shunping county,by the GIS technology and Information Value method.The results show that:(1)The areas with high susceptibility,where rockfalls occur frequently and landslides and mud-rock flows occur in less often,are scattered on the medium-low mountains and hills in the northwestern Shunping with the area about 125 km^2,accounting for 17.5%of the total area of this county;(2)The areas with medium susceptibility,where rockfalls,landslides and mud-rock flows occur occasionally,are widely distributed on the medium-low mountains and hills in the northwestern Shunping with the area about 200 km^2,accounting for 28.0%of the total county area;(3)The areas with low susceptibility,where earth fissures occur occasionally and rockfalls,landslides and mud-rock flows occur rarely,are mainly distributed on the plains in the southeastern Shunping and the wide gullies between the hills in the northwest,with the area about 389 km^2,accounting for 54.5%of the total county area.