| Wuyuan County,located in the northeast of Jiangxi Province,is one of the regions with frequent geological disasters.The geological conditions in this area are complex,along with the development of faults and folds.There are many human engineering activities,such as building houses,construction of roads and development of tourist attractions by cutting slopes in urban and rural areas.Coupled with the influence of extreme weather such as rainfall,geological disasters in this area are intensive and frequent,which poses a significant threat to the property and personal safety of local residents.This thesis takes Wuyuan County as the research area.Based on 1:50,000 geological disaster risk survey and regional disaster destinations and related data(the data of geology,geography,meteorology,hydrology,elevation and remote sensing),the types,characteristics and distribution rules of geological hazards in this research area are analyzed.Twelve factors(such as slope,aspect,elevation,coefficient of variation of elevation,engineering rock group,geomorphic type,NDVI,river buffer zone,road buffer zone,fault buffer zone,multi-year average rainfall and multi-year maximum rainfall)are selected as the disaster causing factors.These factors are classified and geographically detected,and the evaluation index system of geological hazard susceptibility in this research area is constructed according to the results of geographical detection and information model.Then,the weighted information volume-logistic regression model is used to evaluate the susceptibility of geological disasters.Finally,the evaluation results are tested and analyzed.The results indicate that:(1)The geological disaster problem in this study area is relatively serious,with landslides and collapses being the main types of geological disasters,accounting for 99.6% of the total number of geological disaster points.There are many geological disaster points,distributed in a linear pattern,in the northern,central and eastern parts of Wuyuan County,while other regions are relatively few in number and scattered relatively.(2)The main influencing factors of geological disasters are human engineering activities and annual rainfall,with important influencing factors being vegetation coverage and faults in this research area.The coupling of any two of the 12 disaster factors has a stronger effect on geological hazards than the single consistent disaster factor.The interaction between the main control factors and the important factors can significantly enhance the occurrence of geological hazards in Wuyuan County.(3)The weighted information volume-logistic regression model has a good performance in reflecting the linear relationship between the degree of disaster causing factors and the probability of geological disasters,and the evaluation results are in good agreement with reality.This model can be well applied to the evaluation of geological disaster in the middle and low mountain and hilly areas,such as Wuyuan County.(4)In this study area,most of the highly prone geological disasters are distributed in a linear manner,mainly in the human gathering area with an elevation below 200 m and a terrain slope below 15°,the erosion and accumulation valley plain area with relatively soft lithology,the 100 m buffer zone of roads,and the area with an average rainfall of 1800-1900 mm.The high susceptibility areas of geological disasters in this research area are mostly distributed around these extremely high susceptibility areas.It is mainly distributed in the vicinity of human gathering areas and within the 200 m buffer zone of roads.The middle-prone areas of geological disasters in this study area are mainly scattered in the central and western parts of the study area.It is mostly distributed in these low to medium mountains with less human activity ranging from 200-400 m and near fault zones within 300 m.Low-prone areas are widely distributed,accounting for most of the study area.They are mainly distributed in areas with hard lithology and developed vegetation,far away from roads,rivers,and faults,and with an average rainfall of 1800-1900 mm. |
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