Risk Assessment Of Geological Hazards And Route Optimization Analysis Of Kangding-Luhuo Proposed Expressway Based On Multi-Source Remote Sensing

The proposed Kangding-Luhuo Expressway is located on the eastern of the Qinghai-Tibet Plateau.The topographic and geological conditions are complex,the tectonic activity is intense,the development of the Xianshuihe fault is nearly parallel with the line,and the climatic environment is harsh.It is a place with many geological hazards.Geological environmental conditions and geological disasters affect and restrict the selection and construction of the route.In order to ascertain the geological environment conditions and the impact of geological disasters along the line,and to guide and optimize the selection of proposed highway line,this paper carried out a proposed risk assessment and route optimization analysis of the planned highway of Kangding-Huohuo Expressway based on multi-source remote sensing technology and method.Through this research,a set of technical methods for the investigation and evaluation of complex mountain road based on multi-source remote sensing is established,which is based on optical remote sensing,UAV and radar remote sensing to retrieve data——On-site review and analysis——Geological hazard risk assessment considering static and dynamic factors——Quantitative optimization analysis of transmission lines.The main research results are as follows:?1?Interpretation of Geological Disasters based on high-resolution optical remote optical remote sensing image.Using 3D image of the Google Earth and high-resolution GF-2 sensing image,interpret the geological hazards geological environment conditions by combination of manual visual and computer.At last,this paper identify 330 geological disasters,including 75 landslides,collapse 125 at the site,there are 130 mudslides.?2?SBAS-InSAR analysis of slope deformation and identification of potential landslide hazards on the line corridor.This paper get 38 scene image data of the Sentinel-1A radar remote sensing image.Then,it makes the Analysis of surface slope deformation along the line by SBAS-InSAR,and the dentification of potential landslide hazards.At last,15 hidden dangering points of the landslide were found.?3?Verification of geological environment and geological disasters based on UAV and on-site investigations.The study verified the interpretation results based on optical remote sensing radar through field surveys along the line and aerial photography of drones.A total of 345 geological disasters were identified,including90 landslides,125 collapses,and 130 debris flows.Combined with geological environmental conditions interpretation and geological hazard characteristics analysis,geological disasters are mainly concentrated within 900m from the fault,within 400m from the water system,and densely developed in the range of 14°⁴6°.?4?An improved information model for geological hazard risk assessment considering static and dynamic factors.This study analyzes the relationship between geological disaster development and geological environment,and selects static and dynamic factors to establish an evaluation index system.Static factors includes roads,Slope,slope height,slope shape,stratigraphic group,fault structure,seismic peak acceleration,disaster point density and water system;dynamic factors are annual average deformation rate,cumulative deformation variables and rainfall;gray correlation analysis is used to calculate various weights of the factors.Establish a risk assessment model based on improved information method:H=S+W_11j×I_11j+W_12j×I_12j+W_13j×I_13j,and finally realize the risk assessment and division of geological disasters along the proposed highway,which are divided into lower,low,high and higher.The historical disaster data are used to verify the evaluation results.The disasters in the high and higher risk areas account for 80.69%of the total disasters,and the disasters in the middle-risk areas account for 15.65%of the total disasters,the disasters in the low and lower risk areas accounted for 3.66%of the total disasters;the ROC curve verification showed that the accuracy of the evaluation results was 0.82;Both of results show that the risk assessment results are reliable.?5?Quantitative analysis and evaluation of the proposed route.Considering the three factors:geological hazard risk,investment cost and disaster-resistance ability.Then,This paper use AHP to calculate the evaluation value of each selected segment of the proposed line.The optimal comparison scheme is proposed as:?,?-2,?-1,?,?-1,?,?-1,?-2,?-3,?-4,?-1?K162+360-K179+480?,?-2,?-1,?-2,?.?6?Optimal adjustment and suggests of the proposed route.The line segments in the high-risk interval of geological disasters in the above-mentioned optimal comparison scheme are extracted,and line analysis and optimization are performed.The analysis shows that the route planning is basically reasonable,but the high slope at K131+0-K131+450,the collapse disaster at K166+0-K166+200?BT-26?and the debris flow disaster at K213+550-K213+700?NSL-114?has a greater impact on the proposed route.Combined with the geological environment conditions and the possible threat range calculation of geological disasters,it is recommended to shift the line segment?K131+0-K131+450?to the northeast direction by 70m and move to the gentle slope of the river valley;the line segment?K166+0-K166+200?It is offset to the southwest side by 300m;the line section?K213+550-K213+700?is moved 200m to the southwest,and the end of the bridge is changed to K213+900.