Investigation And Analysis Of Geological Disasters On The North Slope Of Qinling Mountains

The northern slope of Qinling Mountains has unique geomorphology and steep terrain,which is a susceptible area of geological disasters occurrence.How to reduce the threats caused by geological disasters,reduce the loss of lives and property,and protect the ecological environment of Qinling Mountains has become hot spots of social concern.In order to explore the types,characteristics,distribution,causes of geological disasters and effectively prevent the threats caused by geological disasters on the northern slope of the Qinling Mountains,this paper obtained DEM data on the northern slope of the Qinling Mountains through field investigations and remote sensing image analysis,using the geographic information system as a platform to synthetically analyze the basic data and characteristics of geological disasters,including topography,geological structure,stratigraphic lithology,and coordinates,elevation,disaster type,scale of geological disaster occurrence points.Finally,we have obtained the following results:(1)Basically identify the main components of the geological strata on the northern slope of the Qinling Mountains,namely,the Mesoproterozoic Kuanping Group(Pt2kn)metamorphic rocks,Yanshanian granite bodies(?5),and the early Quaternary Pleistocene Wucheng loess(Q1),Lishi loess in the middle Pleistocene(Q2),Malan loess in the late Pleistocene(Q3)and Holocene sediments(Q4)and other geological units,which provided the conditions and basis for the study of geological disasters in this area.At the same time,we have divided the geomorphological unit on the northern slope of the Qinling Mountains.It was mainly composed of two large geomorphic units:Mountains and loess plateau.The boundary,which between Mountains and loess plateau,is large normal fault.It belongs to the middle-cutting zone in Zhongshan,and is mainly composed of metaproterozoic Kuanping Group(Pt2kn)metamorphic rocks and Yanshanian granite(?5)bedrock.The north of the fault structure zone is the loess platform area,which belongs to the southern margin of the Weihe graben.The exposed strata are mainly composed of the Wucheng loess(Q1)in the early Quaternary Pleistocene,the Lishi loess in the middle period(Q2),the Malan loess in the late Pleistocene(Q3),and the Holocene sediments(Q4).(2)Identify the main types and spatial distribution laws of geological disasters on the northern slope of the Qinling Mountains.There are three main types of geological disasters:collapse,landslide and debris flow.Among them,there are two types of collapse geological disasters:early collapse and late collapse;landslide geological disasters include old landslide and new landslide.The geological disasters on the northern slope of Qinling Mountains have obvious spatial distribution rules.Collapse geological disasters were mainly distributed in the Mountains landform unit on the northern slope of the Qinling Mountains,which is bedrock collapse.Among them,early collapse was located in the middle of the northern slope of the Qinling Mountains and the exposed altitude range was about 700m-1000m.Late collapse was distributed in the upper and lower parts of the northern slope of the Qinling Mountains and the exposed altitude range is about 700m-800m and 1000m-1300m.The landslide geological disasters were distributed in the loess terrace highland geomorphic unit,which is mainly loess landslides,and the exposed altitude range was about 500m-800m.The spatial distribution of debris flow geological disasters were distributed the two major geomorphic units of Hehuang and Taiyuan.Source generation,circulation and migration were distributed on the northern slope of Qinling Mountains,and the accumulation was mainly distributed at the intersection of the two major geomorphic units of Qinling Mountains and Taiyuan.(3)The formation of geological disasters on the northern slope of the Qinling Mountains has multi-factor characteristics.Among them,the internal factors mainly include rock layer material composition,joint structure,topography and landform features,Quaternary neotectonic movement and other factors,and the main contributors were rainfall intensity and human activities,etc.(4)For the prevention and control of geological disasters on the northern slope of the Qinling Mountains,early warning and prevention,engineering treatment,ecological restoration and reasonable safety avoidance should be taken as the main measures to reduce economic,life and property losses.Through investigation and research,we have summarized the types,characteristics,spatial distribution laws,and the genesis mechanism of the geological disasters on the northern slope of Qinling Mountains,which has certain guiding significance for the prevention and control of geological disasters on the northern slope of Qinling Mountains.