炮江吉勒尕沟泥石流风险定量评价及成因分析

Quantitative Assessment of Debris Flow Risk in Jilega Gully of Paojiang River and Discussion on Its Causes

新疆莎车县达木斯乡7村炮江吉勒尕沟位于地质灾害中高易发区的中高山区,频发的泥石流灾害对当地居民生命及财产安全带来严重威胁。在地质灾害调查基础上,对研究区开展泥石流风险评价及成因分析,为当地新农村和重点工程规划建设提供地质依据。在对新疆莎车县、叶城县地质灾害重点区域调查和资料收集基础上,通过对炮江吉勒尕沟泥石流发育基本特征分析,利用GIS平台、FLO-2D软件等技术对炮江吉勒尕沟单体泥石流进行易发性、危险性、易损性定量评价,做出风险性评价分区图,得出研究单体在不同情境下的预期损失。研究发现,该区泥石流等级为易发,发展阶段为活跃期,在20年、50年、100年一遇降雨频率下,泥石流堆积区最大堆积范围分别为0.0496 km^(2)、0.1055 km^(2)、0.2139 km^(2)。在对单体进行风险性评价后,分别划分出高风险区、中风险区、低风险区。其形成原因复杂,主要与地形地貌、岩土体类型、降水、植被盖度、地震作用、人类工程活动相关。

Jilega Ditch,Pajiang,Village 7,Damusi Township,Shache County,Xinjiang,is located in the middle and high mountainous of the high-prone area of geological disastens.Frequent debris flow disasters pose a serious threat to the lives and property of local residents.However,the hazard caused by debris flow has not been quantitatively evaluated.Based on the investigation of local geological disasters,this paper carries out the risk assessment and cause analysis of debris flow in order to provide geological basis for the planning and construction of local new countryside and key projects.Based on the investigation and data collection of key geological disaster areas in Shache County-Yecheng County on the northem slope of Kunlun Mountain in Xinjiang,and the analysis of the basic characteristics of debris flow development in Jilega Ditch of Pajiang River,this paper quantitatively evaluates the susceptibility,danger and vulnerability of single debris flow in Jilega Ditch,Paojiang River,makes a zoning map of risk evaluation,obtains the expected loss of the research monomer in different situations,and quantitatively expresses it,and further analyzes the causes of the single debris flow by GIS platformn,FLO-2D and other technologies.It is found that the debris flow is prone to occur,the development stage is active.Under the rainfall frequency of 20 years,50 years and 100 years,the maximum accumulation range of debris flow accumulation area is 0.0496 km^(2),0.1055 km^(2) and 0.2139 km^(2) respectively.According to the individual isk evaluation,it is divided into high risk area,medium risk area and low isk area,and it is found that the causes of its formation are very complex,which are mainly related to topography,rock and soil types,precipitation,vegetation coverage,earthquake action and human engineering activities.It provides an important reference for disaster prevention and mitigation and accurate prevention and control of single debris flow.