| China has a vast territory and also has a complex and diverse topographic and geomorphic environment,which results various geological disasters in China.Among them,geological disasters in Sichuan Province are particularly serious.The terrain of Sichuan Province is complex and diverse,and there are many extreme rainfalls.Consequently,the various geological disasters induced by it are very dangerous and harmful,and the speed of causing disasters is rapid.Among them,the landslide is a type of geological disaster that causes serious harm to industrial and agricultural production.Frequent landslide disasters have severely damaged the infrastructure and added tremendous resistance to the modernization of Sichuan Province.At the same time,it has affected the daily lives of the people in Sichuan Province and seriously threatened their lives.The formation of landslide disasters is affected by various elements and precipitation is an important factor affecting landslide disasters.In addition to the impact of precipitation,the landslide disaster in Sichuan Province is also closely related to the fragility of local geological environment.Landslide early warning is means that according to the analysis of the influencing factors of landslides,the weights of various influencing factors are reasonably allocated,and the early warning model is constructed according to certain algorithms.According to the characteristics of landslide disasters in Sichuan Province,the proneness evaluation of landslide disasters in Sichuan Province was first carried out,and the results of the proneness evaluation were used as the geological environmental factors to construct a landslide warning model.Through the analysis of historical landslide disaster data and historical precipitation data,the grading thresholds of cumulative precipitation and timely incentive precipitation were calculated respectively.The result of precipitation threshold analysis was used as the precipitation factor to construct a landslide warning model.Taking Tongjiang County and Xide County in Sichuan Province as examples,two early warning models for landslide disasters were constructed,and the early warning results of these two models were compared and analyzed by using historical data.A landslide early warning system is constructed by selecting a landslide early warning model with higher early warning accuracy.Based on the landslide disaster in Sichuan Province,the following work is accomplished:(1)Eight evaluation factors are selected to evaluate the proneness of landslide disasters in Sichuan Province,including slope,aspect,elevation,stratigraphic lithology,vegetation coverage,distance from landslide site to river,distance from landslide site to highway,and distance from landslide site to residential area,which can be divided into five levels.(2)The regionalization result of the landslide disaster occurrence is verified by using rationality verification and precision verification methods.(3)Taking Tongjiang County and Xide County as examples,the relationship between landslide disasters in Sichuan Province and cumulative precipitation and timely precipitation was studied.In addition,the cumulative precipitation threshold and the timely incentive precipitation threshold of the two places were calculated.(4)Taking Tongjiang County and Xide County as examples,two early warning models of landslide disasters were constructed,and the accuracy and comparative analysis of the early warning results were carried out.Finally,a geological-meteorological coupled early warning model was selected to construct a landslide early warning system.(5)The system design is carried out according to the actual functional requirements of the system.Based on WebGIS and related system development technology,the system development and testing are completed. |
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