The Study Of Area Prone To Partition Geological Disaster In Guizhou Chishui River Basin Based On GIS

It is located in the Chishui River Basin in the northwest of Guizhou Province.It is bordering the south of Chongqing City,west of Sichuan Province and Yunnan Province.The river basin flows through more than 10 counties(cities or districts).The region is mainly northeast to fold fracture.In addition to individual strata,from the Neoproterozoic Sinian to the Mesozoic Cretaceous are exposed.The stratigraphic structure in the area is complex,and the surface fluctuation is obvious.The landform types in the study area are mountainous(middle mountain,low mountain),hilly-based,and the relative height of the whole area has reached 2277 m.Coupled with the dense distribution of the river network,the impact of human activities and global warming.Under the combined influence of these factors,the increase of probability of occurrence of geological disasters such as landslide,debris flow and collapse in the study area has been increasing in recent years.The occurrence of disasters on the people's lives and property security caused great damage.It is of great reference value to study of area prone to partition geological disaster and analyze the regulation of distribution and put forward the countermeasures to prevent and reduce the occurrence of geological disasters and carry out tourism development and urban planning in the future.This paper combines the 901 geological hazard points that have occurred in the Chishui River Basin.In addition,the use of GIS technology,mainly to ArcGIS,Envi or Erdas software as a platform,the use of information model for the study area of geological disasters prone to partition.The research results mainly include the following aspects:(1)Based on the unique functions of GIS,such as storage,analysis,processing and visualization of spatial data,the extraction of the required factor data at each stage of geological disaster zoning is completed,and the database of intermediate data generated during the process is established.Based on GIS technology and remote sensing image,topographic map,etc.,including slope,fluctuation,aspect,NDVI(vegetation normalization index),geological rock group,landuse type,soil,river network,road and so on of the nine basic factors are extracted.The database includes the base factor,the intermediate process data,and the resulting data.(2)To study the relationship between geological hazards and geological hazards in Chishui River Basin,and to analyze the law of occurrence of geological disasters.According to the analysis of the distribution law of each factor and geological hazard,it is found that there are obvious zonal distribution characteristics of geological disasters in the study area,which is closely related to the complicated geological environment background.There are significant correlations between the geological hazard points in each factor: in the slope between 15-20 °,the fluctuation between 20m-30 m,the slope direction to the southwest direction,NDVI?0.1,and the stratigraphic rock group is the weak rock strat layer,and the cover type is the human settlements,Near the river,and the soil type is paddy soil,within 100 m from the river system,within 100 m from the road,the probability of occurrence of geological disasters under these conditions is relatively large.(3)Obtain the results of the geological disaster prone distribution in the Chishui River Basin.The results of the evaluation show that the middle prone area,the high prone area and the extremely high prone area together accounted for are more than 50% of the total area,which indicates that the overall sensitivity of the area is large and the protection should be paid attention to when developing and utilizing.The total extremely high prone area of the study area is 1347.7km2,accounting for 11.55% of the total river area.To the town of Xishui County-Tucheng Town-East Town-Chengzhai Township-Sancha Township-Dapo Township-Zhaiba Township-Naiba Township direction and Tongzi County Gaoqiao Town-Jiuba Town-Lou Yamaguchi town direction as the main distribution area;The area of the high prone area is 2442.7km2,accounting for 20.93% of the total river basin area,and its distribution range is similar to that of the extremely high danger zone,which is mainly distributed around the latter;As a geological disaster prone area and the prone area of excessive zoning,the total area of the prone area is 3259.66km2,accounting for 27.94% of the total watershed area,the largest proportion of area.In addition to the small part of Chishui City,most of the other cities and counties are distributed;the area of the lower prone area is 2965.01 km2,accounting for 25.41% of the total watershed area.This part has the spatial consistency with the distribution of the low prone area,which is mainly distributed in Chishui City and mass distribution in other parts.In most cases,vegetation growth is good;the total area of the prone area is 1652.99km2,accounting for 14.17% of the total area of the study area,and the distribution is mainly concentrated in the northern part of the Chishui River Basin.