Database Construction And Hazard Assessment Of Geological Disaster In Loess Plateau Of Shan-gan-ning Region

Select Loess Plateau of Shaanxi province,Gansu province and Ningxia Hui Autonomous Region(Shan-Gan-Ning Rigon for short)as the study area,landslides,collapse,debris flow,hidden danger of landslide and collapse for research objects,to conduct the hazard assessment of geological disasters in the Loess Plateau by using GIS technology.It provides scientific basis and decision-making system support for the construction of geological disaster management system in large area for government departments,and provides the basis for the engineering construction regionalization and disaster prevention and mitigation in the Loess Plateau.Based on the correlation theories of the research on the geological hazards of the loess,draw on the experience of latest research results at home and abroad,on the basis of the existing classification of geological disasters,do the further analysis of the relationship between various types of geological hazards and their development factors,such as precipitation,topography,vegetation,strata,structure,earthquake,human activities and other factors,to reveal the conditions for the development and spatial distribution regularities of geological hazards;and further clarify the main controlling factors and inducing factors in the development of geological disasters in Shan-Gan-Ning Region of Loess Plateau.Combined with the correlation theory of the research on the geological hazards in the Loess Plateau and the latest research achievements at home and abroad.to use of detailed survey data of geological disasters in Shan-Gan-Ning region in recent years,collect and sort out the geological hazard data,building metadata and databases of geological disasters in Shan-Gan-Ning region and develop the research of geological disasters in Shan-Gan-Ning region of the Loess plateau by compilation distribution map and hazard zoning map of geological hazards in Shan-Gan-Ning Region of Loess Plateau.Research on the data set classification,data retrieval and analysis,data distribution and sharing,establish the metadata as the basis of database of geological disaster in Shan-Gan-Ning region of the Loess Plateau.according to the "geological information metadata standard".Established a relatively complete metadata and database in Shan-Gan-Ning region of the Loess Plateau,according to the different types of geological disasters,different database data structures are given,and storing the data.Analyze the the relationship between various types of geological hazards and main control factors and induced factors,to reveal the conditions for the development and spatial distribution regularities of various geological hazards;And then initially improved hazard assessment method and index system in Shan-Gan-Ning region of the Loess Plateau,to clarify the basic content and implementation steps of geological hazard assessment in Shan-Gan-Ning region of the Loess Plateau by using the method of combining analytic hierarchy process with information method,.Most of the existing hazard assessment database is based on county area,a few for the city,or provincial.However,the change of geological disasters is related to the large area and the same geomorphic condition,combined with the influence of many external conditions,such as precipitation,topography,tectonics,earthquake,vegetation,human activities,ect.Carrying out the hazard assesment by established spatial database with Continuous change process in large area,such as the Loess Plateau.And solving an important problem which needs to be solved urgently in the scientific research of geological hazards.The results of the hazard assessment of geological disasters in Shan-Gan-Ning region of the Loess Plateau showed that the sky-high hazard area of geological hazard is about 74787.0km2,accounting for 20.4% of the total area,the development of the disaster point is 6967,the average density of disaster point is 0.093 /km2;the high hazard area of geological hazard is about 103122.9km2,accounting for 28.1% of the total area,the development of the disaster point is 4454,the average density of disaster point is 0.043 /km2;the middle hazard area of geological hazard is about 65217.7km2,accounting for 17.8% of the total area,the development of the disaster point is 552,the average density of disaster point is 0.008 /km2;the low hazard area of geological hazard is about 59663.3km2,accounting for 16.3% of the total area,the development of the disaster point is 69,the average density of disaster point is 0.001 /km2;the extremely low hazard area of geological hazard is about 63893.8km2,accounting for 17.4% of the total area,the development of the disaster point is 80,the average density of disaster point is 0.001 /km~2.