| In recent years, serious natural disasters caused serious losses. The geologicaldisaster risk research can help people to understand regularity of outbreak ofgeological disasters and develop as suitable geological disaster prevention and controlmeasures to reduce or eliminate the human damage. This thesis is based on the projectof Detailed Survey on Geological Disasters in Xinhua County. Through the field workand the indoor work, the author has comprehensively mastered the general types anddistribution characteristics of Xinhua’s geologic hazard. With an analysis on varioustypes of geologic hazards’ development features and formation conditions, asystematic and comprehensive understanding of the general characteristics ofXinhua’s geologic hazards development have been mastered in this thesis, whichplays an important role for the county’s risk zoning and evaluation The main resultsare as follows:1. The types of geological disasters in Xinhua County are landslides, unstableslopes, landslides, mudslides, ground subsidence, ground fissures, etc., mainlylandslides and unstable slopes disasters. The study found908geological hazards,including345unstable slopes, accounting for38%of total hazard point;428landslide,accounting for47.1%of total hazard point;20collapse, accounting for2.2%of totalhazard point;18mudslides, accounting for2%of total hazard point;92groundsubsidence; accounting for10.1%of total hazard point;5ground fissures, accountingfor0.6%total hazard points.2. The landslides, unstable slopes geological disasters mainly occurs in hillytopography on300m-700m altitude; collapse geological disasters occurs in slope of50-90°shaped landform; karst ground subsidence geological disasters mainly occursin karst hilly lowland topography; debris flow mainly occurs in river valleys landformdevelopment3. The main types of rock soil mass of geological disasters are carbonate rocksand clastic rocks; the main types of slope structure is consequent slope; geologicaldisasters are closely related to fractures; precipitation is the main trigger factors of geological disasters, mainly occurred in1996and April-July in2012; geologicaldisasters are affected by human activity significantly, accounting for47.86%of thetotal.4. This paper chooses density, gradient distribution, geomorphic type and altitude,rock soil mass type, river distribution, fault developmental degree, precipitation andhuman engineering activity intensity of geological disasters as assessment indexes forrisk assessment; According to the degree of influence of each evaluation factor for thedevelopment of geological disasters, completing the geological disaster risk zoning ofXinhua county by MAPGIS by using the analytic hierarchy process model; the zoningresults are classified as high, medium and low risk areas.There are three high riskzone,44.8%of the total area; three in the danger zones,28.5%of the total area,; twolow risk zones,26.7%of the total area. With the degree of risk determined, the paperput forward the measures of geological disaster prevention in Xinhua County. |
