Rainfall threshold analysis method causing basin landslide risks

Abstract

The invention relates to a geological disaster prediction and forecast technology, and aims to provide a rainfall threshold analysis method causing basin landslide risks. The method comprises the following steps: establishing a three-dimensional grid according to DEM topographic data and soil layer thickness data of a target watershed, and generating boundary conditions and initial conditions required by an RIRM hydrological model; calculating space-time changes of hydrological elements in the drainage basin and drainage basin slope stability reference indexes of any three-dimensional positionin the drainage basin; drawing a relation curve that the safety factor SF, the landslide volume and the landslide area respectively change along with time under the conditions of different rainfall durations and different rainfall intensities; analyzing the relationship between landslide deformation damage and rainfall to obtain rainfall thresholds causing basin landslide risks under different conditions. According to the method, natural basin geomorphic hydrological response characteristics are reserved, and prediction errors can be effectively reduced; drainage basin hydrology and slope stability analysis can be carried out simultaneously, the actual occurrence process of drainage basin landslide disasters is met, and the prediction result is more real and reliable.

Description

technical field [0001] The invention relates to geological disaster prediction and forecast technology, in particular to a rainfall threshold analysis method that causes landslide risk in a watershed. Background technique [0002] Landslides and collapses are one of the main natural disasters in mountainous areas. They not only cause huge losses to industrial and agricultural production and people's lives and property, but also cause great harm to railways, highways, water conservancy and hydropower projects, etc. The occurrence and development of landslides are not only controlled by the formation conditions (topography, geological lithology, geological structure, hydrogeological conditions, etc.), but also affected by inducing factors (rainfall, human activities, etc.). Heavy rain, especially continuous heavy rainfall, is one of the important factors causing landslides; the effect of rainfall on landslides is mainly manifested in the infiltration of a large amount of rainw...

AI Technical Summary

Problems solved by technology

The hydrological model based on empirical concepts is relatively simple and developed earlier. The coupling model established on this basis has been widely used, but it needs to perform depression filling preprocessing on the terrain when solving it, which reduces the accuracy of the model; in contrast, Hydrological models based on physical concepts are rich in simulation information and can capture the spatiotemporal changes of various hydrological elements. However, due to the complexity of the solution, the calculation requirements are high, and the development of hydrological-landslide coupling models based on this is relatively late.

In summary, the existing technology based on statistical principles to analyze the mathematical relationship between landslides and rainfall requires a huge amount of geological, climate, and disaster data, which is difficult to meet in general areas; combined with hydrological models based on empirical concepts and infinite slope stability models to The method of estimating the rainfall threshold cannot reflect the real physical process in nature, providing less information and lower accuracy

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