| Landslide is the main part of the geological disaster in Sichuan Province,it will not only bring threats to people and property,but also affects the progress of society.Therefore,it is necessary to study the factors of landslide,calculate the susceptibility regionalization,add up the rainfall information of landslide,explore the rainfall threshold in typical areas and establish the rainfall-induced early warning model of landslide in Sichuan.The main contents of this paper are as follows:(1)Based on the comprehension of geological environment and research of factors on landslide in Sichuan region,the paper established the susceptibility regionalization by the weighted information value model,and the Sichuan province was divided to 4 part: low-prone area,medium-prone area,high-prone area and extremely-high-prone area.The result was verified by the inspection points,more than 78.7% of the disaster spots fell into the areas above the medium-prone area.23.27% of the disaster spots fell into the high-prone area,and 17.43% of the disaster spots fell into the extremely-high-prone area.(2)Used the detailed meteorological data and landslide disaster information to explore the temporal and spatial distribution characteristics of rainfall and landslides.Added up the relationship among landslide and the daily rainfall,the landslide and the continuous rainfall days,the landslide and cumulative rainfall.And analyzed the relevance between the rainfall and landslide.After the above,the paper proved the close relationship between landslide and rainfall,and verified the relevance among them.(3)Through the study of the rainfall threshold model,the paper studied the landslide rainfall threshold of three typical cities with its county and the preliminary research susceptibility regionalization.The paper obtained three rainfall threshold for Aba,Bazhong and Chengdu and for 4 susceptibility areas.The threshold model was verified that the accuracy rate is above 89% in every susceptibility area and the total accuracy rate is 92%.The effect of the threshold curve is good.(4)Based on the previous research results,mainly the susceptibility regionalization and rainfall factors,constructed a rain-induced landslide early-warning model based on logistic regression analysis,the model was tested by ROC curve,and the AUC value is 0.833,it is good to simulate the effect of disaster.The paper used the disaster points that do not participate in the model to verify the model.And the results are as followed: 79.44% of the disaster points reached three-level early warning level,72.01% of the disaster reached two-level early warning effect,62.96% of the disaster reached the first-level warning effect.In conclusion,the model has a good warning ability.Through the verification of the results,it can be concluded that the above results have a certain reference value to the study of the landslide meteorological early warning model in Sichuan area. |
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