| In the southwest region of China,the occurrence of geological hazards caused great loss and been a obstacles to the development of the motherland.Geological disaster risk assessment is an effective method of disaster prevention and mitigation,it not only has the guiding significance of disaster prevention and mitigation,but also provides a useful way and research foundation to research the law of the slope active and regional geological environment develop.After years of scholars' research,the geological disaster risk assessment areas built a set of relatively mature theoretical system and logical system.The geological disaster risk consists of two parts,which is the geological hazards assessment and vulnerability assessment respectly.Geological disaster risk assessment was based on the research of the mechanism of geological disasters in the area,to a specific breeding environment,choose the necessary conditions of geological hazards as evaluation index,analyze correlation of the evaluation index and the of geological disasters,take an appropriate mathematical statistical model do geological disaster risk assessment.Geological disaster vulnerability aims at the value of the resources for human and reduce the economic losses caused by after disasters.Combined with the geological disaster hazard assessment and vulnerability assessment,according to the classification of distribution regularity of the domain,multiply the geological disaster risk assessment results are obtained.In recent years,the geological disaster risk evaluation theory system can play a role in disaster prevention and mitigation,but with the rapid development of science and technology,take the high and new technology of RS and GIS into the geological disaster risk evaluation system is inevitable.In addition,previous geological disaster risk assessment theory system did not took slope activity into the evolution of geohazard,it will cause a certain influence to the final evaluation results.At the same time,the existing geological disaster risk evaluation with the characteristics of a "one-off",which can only used for a specific period and the certain characteristic of environment effectively,did not suitable for evaluation of geological disaster risk to a changing environment.Based on the above consideration,this article take the Period of Mangkang county of Sichuan-Tibet Interconnection Project of State Grid as an example,from qualitative and quantitative understanding the activity of the slope,constructed the geological disaster risk evaluation index system with considering the slope activity.Based on the basic data and evaluation object,choosing the weighted information model completed geologic disaster dynamic hazard evaluation of the study area,put forward the core target model to vulnerable assessment aiming at the core of the transmission,finally realized the geological disaster risk assessment.At the same time,classified the geologic disaster hazard evaluation index,built the dynamic evaluation model of geological disaster hazard,combined with vulnerability assessment results,bulit the geological disaster risk dynamic assessment model finally.Through a series of analysis,the following results are obtained:1.Comparative analyzed the remote sensing interpretation method and operation process to various kinds of disaster,combined with the actual situation,choosed the useful completed the historical disaster interpretation by analyzing the categories and characteristics of study region,while analyzing the law of historical space distribution.2.Use the density by historical disasters qualitative analyze and the deformation data of InSAR interpretation deformation quantitative analyze the activity condition of study area.Combining the idea of the slope evolution cycle and deformation characteristics of the slope,built evaluation index system based on the slope activity index;3.Consider the correlation of slope active state of geologic disaster and evaluation index system,using partition statistics tool of GIS,calculate the parameters of historical disasters of each index in the unit.Taking weighted information model to complete the geological disaster hazard assessment based on slope activity.At the same time,the risk evaluation index is divided into a value(static index)and dynamic index system of sustainable update(average deformation rate and cumulative displacement)two types,built the dynamic evaluation model of the geological hazard;4.Aiming to the specific atrget of transmission,the paper classified the study region into transmission construction geomorphic units and non transmission construction geomorphic units.To the first type,give the vulnerable value as 2-4 by the density of the transmission construction,the others give the value as 1.This is the core target model of transmission construction.5.After evaluated the result's effectiveness of the risk,according to the "risk = x vulnerability risk" model completed the geological disaster risk assessment of the study area.Analyze the regional hazard,vulnerability and risk result,builds the dynamic evaluation model of geological disaster risk.Sorting the required data of post evaluation,provides a dynamic examples and idea to risk dynamic evaluation of geological disasters in other areas. |
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