Susceptibility Assessment Of Shallow Landslides In Chenxi County Based On SINMAP And TRIGIS Models

Rainstorm-induced shallow landslides are the most common types of landslides in nature.It is one of the hot issues in the study of landslide disaster at home and abroad that the development of torrential landslide susceptibility is based on different methods.The SINMAP and TRIGRS models are currently widely used in both domestic and international torrential landslide susceptibility evaluation models,both of which are GIS-based,coupled with a steady-state hydrological model and an infinite slope stability evaluation quantitative model,suitable for evaluation Regional bursts of Rainstorm-induced shallow landslides.However,these two types of models are less frequently used in the flood-prone shallow landslide areas.In order to compare the application effects of the two evaluation models in the shallow rain landslides in southern China,the study of the susceptibility of shallow landslides was conducted in Chenxi County,Hunan Province.Chenxi County,Hunan Province is a hilly area with multiple storms.The accumulation of accumulated sediments on the slopes in the area is extensive,and shallow landslides often occur.Based on the analysis of the formation conditions of landslides in the study area,this paper based on two models of the stormy shallow landslide susceptibility evaluation in the study area,the main research results obtained are as follows:(1)The SINMAP simulation results show that under the storm conditions of 20 years,the area of extremely unstable and unstable regions is approximately 1.39km~2,accounting for 6.07%of the total area of the study area,and the area of potential instability is 5.131km~2,accounting for the total area 22.30%of the area.The area of basic stable to extremely stable area is 16.485 km~2,accounting for 71.64%of the total area of the study area.The verification results of the classification error matrix method show that the correct rate of the model prediction result is89.98%.(2)TRIGRS simulation results show that in the case of one-time heavy rainstorm in 20years,the area of unstable area is about 1.414km~2,accounting for 6.15%of the total area of the study area,and the area of potentially unstable area is 2.467km~2,accounting for 10.72%of the total area of the area..The area that basically stabilized to a stable area was 19.13km~2,accounting for 83.14%of the total area of the study area.The verification results of the classification error matrix method show that the accuracy of the model prediction result is88.85%.(3)In the stability calculation of SINMAP model,the scale is the unit sink area a,and the TRIGRS model calculates the stability coefficient of each grid by calculating the stability coefficient of each grid.The stability index calculated by the SINMAP model is not a completely deterministic value.It is a quantitative value of the landslide occurrence probability.The stability factor calculated by the TRIGRS model is a definite value.Therefore,when verifying the accuracy of the model,the accuracy of the former is higher.(4)The results of susceptibility zone of shallow landslides in the study area:(1)The area of high-prone areas is 1.40km~2,accounting for 6.06%of the total area of the study area.They are mainly distributed in the northeastern part of the study area on both sides of the Maxi River valley,on the south side of the steep valley of the river valley in the Anping-Songjiashan area,on the south side of the steep rock mountain in the east of the Lutou Park,on the east slope of the Liuxiao Park in the central part,and along the Hujiapo slope.The steep slope along the Yuanjiang(2)The area of easy-to-produce areas is 5.14km~2 with a large area of distribution,accounting for 22.34%of the total area of the study area.They are mainly distributed in the steep slopes on the north and south sides of the steep rock mountain in the east,the hilly areas between the Qilitai reverse fault and the Baiyan Mountain in the west,and are scattered in other areas.(3)The area of low-prone areas is 3.29km~2,accounting for 14.31%of the total area of the study area.Located in the middle of the lower slopes and slopes in the hilly area of the whole area.(4)The area of hard-to-produce area is 13.18km~2,accounting for 57.29%of the total area of the study area.