Study On Hydrology-Mechanics Coupling Model For Landslide Prediction

The landslides induced by rainfall are the natural disasters and make threaten to the man lives and estates. Traditional methods of slope stability analysis and prediction couldn't be suitably applied to study large zone landslide hazards because the rainfalls and the related factors of landslides are spatially distributed, additionly because the traditional analytical methods of slope stability are costly and their techniques are complicated. It is potential to study landslide hazards in large zone through modern information technologies with the developing of GIS, RS, spatial database and computer. The main reasons to cause landslides are that rainfall causes the rise of ground water table and the increase of subsurface soil water. The paper constructs hydrology-mechanics coupling model of the landslide prediction. In the model systems, the change of ground water table and soil water ared computed with physical-based distributed hydrological model, the factors of slope stability are calculated with the 3D limit equilibrium method. This research has important theoretical and practical meanings.In this paper, to summarise the productions of the former researchers and documents related to the landslide hazards, to sum up the influencing factors and the unstability mechanism of slope unit, finally the hydrology-mechanics coupling model for the landslide prediction is constructed, and its parameters and input data are provided. Firstly slope units and finite difference meshs should be divided automatically. Study the spatial data model, hydrological analysis and terrain analysis based on DEM. Extent the existing functions of spatial analysis and hydrological analysis, and it is accomplished that slope units and finite difference meshs are divided automatically.Rainfall-surface flow is effectively simulated by physical-based distributed watershed model because this model considers the spatial distributions of vegetation coverage, land use, topography and geology. Construct small watershed slope hydrological model to simulate the groundwater fluctuation and the change of soil water after the principles of SHE model and its extended model are summarized. The limit equilibrium method is widely applied in slope stability field according to the characteristics with the distinct concept and the simple formulation. Based-grid limit equilibrium method is suited to analysis the slope stability while ground water table fluctuates and soil water changes with time.The architecture of the hydrology-mechanics model is described, and the important technologies are studied for example the constructions of soil seepage and subsurface water flow mathematical models, the construction and solution of finite difference formulations, and the arithmetic of hydrology-mechanics model. The procedure of hydrology-mechanics model is designed and developed. Finally this model is verified in the Japanese landslide modeling caused by the continuously heavy rainfall.