【作者】 徐帮树；

【导师】 徐建华；

【作者基本信息】 华东师范大学 ， 地图学与地理信息系统， 2006， 博士

【摘要】 降雨触发的滑坡是频繁发生的地质灾害，对人类的生命和财产构成严重威胁。由于降雨触发的滑坡及其影响因素具有时空分布的特点，传统的对单个边坡的稳定性分析和滑坡预测方法由于费用高，技术复杂，远远不能满足区域滑坡灾害研究的需要。近年来，随着地理信息系统、遥感技术、空间数据库和计算机技术飞速发展，运用现代信息技术对区域的滑坡灾害制图和预测成为可能。以GIS为技术平台，考虑降雨引起的地下水位波动和土壤含水量增加对边坡稳定性的影响，构建小流域滑坡预测的水文-力学耦合模型，预测降雨触发下滑坡的发生，具有重要的学术意义和应用价值。 总结前人基于GIS对滑坡灾害的研究方法和成果，同时查阅滑坡灾害文献资料和对日本滑坡实例进行分析，归纳出降雨引起滑坡的影响因素及边坡破坏机理，构建小流域滑坡预测的水文-力学耦合模型：采用有限差分算法，基于物理的小流域滑坡分布式水文模型模拟地下水位波动和土壤含水量的变化；以边坡单元为研究对象，基于栅格数据的极限平衡方法计算边坡安全系数；在计算过程中实现地下水模拟与边坡安全系数计算的耦合，预测滑坡的发生。 运用水文-力学耦合模型预测滑坡，首先要对研究的小流域进行边坡单元划分和研究范围进行空间离散。以栅格数据的数字高程模型(DEM)为基础，研究DEM对空间数据的存储格式，水文分析和地形分析算法。扩展现有的GIS水文分析和三维建模功能，实现基于栅格数据的边坡单元自动划分和有限差分网格的自动生成。 SHE及其改进模型是基于物理的分布式流域水文模型，能够模拟植被、地形、地质等因素的空间变化对流域降雨-径流影响，此类模型具有明确物理学机制，能够适用于不同流域。本文借鉴SHE模型的思想，建立小流域滑坡水文模型，用来模拟地下水位波动和土壤含水量的变化。小流域在水平方向上由正方形栅格组成，垂直方向上简化为树冠、非饱和层和饱和层三层结构。非饱和层土壤水流用一维Richards微分方程描述，饱和层水流用三维渗流微分方程描述。 极限平衡方法具有概念清晰，数学表达简洁等特点，被广泛用于边坡稳定性分析。但在GIS中运用三维极限平衡方法进行滑坡研究还不多。本文考虑随时间过程降雨入渗引起的地下水位波动和土壤含水量变化，采用三维极限平衡方法，建立基于DEM的边坡力学模型，计算边坡安全系数，分析边坡的稳定性和预测滑坡的发生。 对滑坡预测的水文-力学耦合模型计算过程中信息交互进行描述，并对其实现的关键技术进行研究，如建立壤中流、地下水流非稳态流动的数学模型，推导其有限差分方程和求解过程，水文-力学耦合模型滑坡预测的算法。在以上研究的基础上，对水文-力学耦合模型程序进行设计和编程。最后，以日本熊本县宝川集村滑坡为例，进行滑坡发生预测的模拟，验证模型的合理性和可靠性。更多还原

【Abstract】 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.更多还原