基于GIS与Scoops3D的水动力型滑坡区域稳定性分析∗

Stability Analysis of Hydrodynamic Landslides in the Reservoir Area Based on GIS and Scoops 3D

摘要:

库岸边坡在库水位变动、降雨等水动力因素的作用下易发生水动力型滑坡，进而威胁库区居民生命及财产安全。以某流域 HD 和 DHQ 库段为主要研究区段，在对已有滑坡点进行地质调查和遥感解译的基础上，将 ArcGIS 的空间分析与三维斜坡稳定性分析模型（Scoops 3D）相结合，对研究区段的潜在滑面进行系统的三维搜索及识别，并基于 GIS 数据与室内试验等确定计算参数，对天然和暴雨两种工况下的区域滑坡稳定性进行评价比较。结果表明：（1）研究区历史滑坡点分布与基础地质环境、岩土体强度指标参数有很强的相关性；（2）天然工况下，非稳定区主要分布在 DHQ 坝区、迤场、DH 坝址、拉巴铁、宝塔河以及甸尾附近；（3）暴雨工况下，非稳定区面积较天然工况有显著的增大，DHQ 坝址、营盘镇、甸尾、HD 坝址附近有较为密集的分布；（4）暴雨工况下模型计算的非稳定区与历史滑坡点的分布特征基本一致。由此可见，三维斜坡稳定性分析模型可以较为准确模拟不同工况下滑坡稳定性， 且易发程度区分明显，稳定性评价结果在一定程度上反映了研究区段的稳定性时空分布。

Abstract:

Under the impact of hydrodynamic factors such as reservoir level fluctuations or rainfall， the slope in the reservoir area is prone to hydrodynamic landslides， thus threatening the life and property safety of residents in the reservoir area. Based on the geological investigations and remote sensing interpretations of the existing landslides in the research region， the spatial analysis of the ArcGIS was combined with the three-dimensional slope stability analysis model （Scoops 3D） to perform a systematic three-dimensional search and identification of potential landslides in the main study reservoir from the HD section to the DHQ section. The calculation parameters were determined based on the GIS data and laboratory tests. The regional landslide stability under natural and rainstorm conditions was evaluated and compared. The research results indicate that：（1） the distribution of historical landslides in the research region has a strong correlation with the geological conditions and the strength parameters of the rock and soil；（2） Under natural conditions， the unstable area is mainly distributed in DHQ section， Yichang， DH dam site， Labatie， Baota River and near Dianwei；（3） Under rainstorm conditions， the distribution range of unstable areas is significantly larger than that in the natural conditions， unstable areas are densely distributed near the DHQ dam site， Yingpan Town， Dianwei and HD dam site；（4） The distribution of unstable areas calculated by the model under the rainstorm conditions is basically consistent with the distribution characteristics of historical landslides. It can be seen that the three-dimensional slope stability analysis model can accurately simulate landslide stability under different working conditions， and the degree of susceptibility can be distinguished clearly. The calculation results reflect the spatiotemporal distribution of stability in the research region to a certain extent.