金寨县地质灾害类型及发育特征

TYPES AND DEVELOPMENT CHARACTERISTICS OF GEOLOGICAL HAZARDS IN JINZHAI COUNTY

通过对地质灾害的类型、斜坡结构、岩性特征、分布高程、地形坡度进行详细的野外调查,并运用统计学进行梳理分析。研究区发育主要地质灾害为滑坡、崩塌、不稳定斜坡和泥石流,共计144处地质灾害,灾害点密度3.78处/100km^2。空间上分布不均匀,呈南北多,中部少,且各乡镇分布具有明显的不均匀性。在地形上多发育于相对高差在200~1000m之间的中低山及相对高差在30~200m之间的丘陵地区。时间上,年际主要集中发生在2003年,1991年、1998年、1999年这三年也有少量发生,2008年以后也较其他年份多。年内主要发生在6~9月,与连续性强降水关系密切。诱发地质灾害的内部控制因素主要为地形地貌条件、地层岩性、边坡结构类型和地质构造特征。外部控制因素主要为降雨和人类工程活动。

Through a detailed field survey and statistic analysis of the types,slope structures,lithological characteristics,distribution elevations,topographic slopes of geological hazards,this paper finds that main geological hazards in the study area are landslides,collapses,unstable slopes and debris flows,occurring in a total of 144 places with a density of 3.78 ones /100km2, which are unevenly distributed in terms of space and twonships,with more in the north and south than in the middle,topographically concentrating in mid- low mountains and hilly areas with a relative height difference of 200~1000m and 30~ 200m,respectively,temporally clustering in 2003,also in 1991,1998 and 1999,and more in years after 2008 than in other years,mostly taking place in June to September in a year.The hazards are closely related to the continuous heavy precipitation. The internal control factors that induce geological hazards are mainly topographic and geomorphic conditions,stratigraphic lithologies,slope structure types and geological structure characteristics.The external ones are rainfall and human engineering activities.