基于InSAR技术的蠕动型滑坡变形三维演化特征分析与建模

As an emerging surface deformation monitoring method, InSAR is widely used in the monitoring of geological disasters such as land subsidence. Improve the effectiveness of InSAR in monitoring landslide deformation over a wide area has always been a key point in landslide monitoring. Through previous theoretical and experimental studies, it is shown that the three-dimensional evolution characteristics of InSAR monitoring results are closely related to the degree of landslide hazard. There are few researches on the establish models that reflects the overall evolution of the landslide area, and are mostly limited to one or two dimensional models. So this proposal is intended to optimize the solution method and result interpolation method of landslide displacement with InSAR to build three-dimensional deformation field of landslide. According to this field, it will reveal the deformation evolution process, statistical analyze landslide evolution characteristics the evolution characteristics of the landslide, and summarize the evaluation method of landslide deformation localization degree. Based on a typical data posterior test method of slow-moving landslide, the proposal is intended to study on the correlation between the degree of localization of landslide deformation field and the process of its sliding failure, and propose a landslide risk assessment method and its GIS program based on local indicators. In additional, this study has raised the accuracy and applicability in monitoring the quantitative risk assessment of slow-moving landslide with InSAR, and it has high theoretical significance and application value.

InSAR技术作为一种新兴的地表形变监测手段，广泛应用于地面沉降等地质灾害的监测，而提高InSAR技术在广域范围内监测滑坡变形的有效性一直是此类监测中的关键难点。通过前期理论及实验研究表明，InSAR监测结果的三维演化特征与滑坡危险程度密切相关，而基于InSAR监测结果数据建立反映滑坡区域整体演化的模型研究较少，且多局限于一维或二维模型，因此本课题拟优化InSAR技术中滑坡体位移的求解方法和结果矢量插值方法，构建滑坡体三维变形场，考察滑坡变形局部化演化过程，并对其演化特征进行统计分析，提出刻画滑坡体变形局部化程度的评价方法。基于典型的蠕动型滑坡监测数据后验检验方法，研究滑坡变形场局部化程度与其滑动破坏过程之间的关联，提出基于局部化指标的滑坡危险性评价方法，完成评价模型的GIS程序开发。课题有助于提高InSAR技术监测蠕动型滑坡定量危险性评价的精度和适用性，具有较高的理论意义和应用价值。

我国是世界上受地质灾害影响最严重的国家之一，近十年来我国遭受的滑坡灾害在所有地质灾害中所占比例高达72.4%，滑坡灾害的监测与防治俨然已经成为当务之急。InSAR技术作为一种新兴的地表形变监测手段，广泛应用于滑坡、崩塌、地面沉降等地质灾害的监测，而提高InSAR技术在广域范围内监测滑坡变形的有效性一直是此类监测中的关键难点。本研究在选定金沙江流域、大渡河流域、雅鲁藏布江流域、三峡库区等典型西南高山峡谷区域等几个滑坡集中发育的地区为研究区域，优化InSAR技术中滑坡体位移的求解方法和结果矢量插值方法，构建滑坡体三维变形场，考察滑坡变形局部化演化过程，并对其演化特征进行统计分析，提出刻画滑坡体变形局部化程度的评价方法。结合与坡度、坡向的空间关系推导出滑坡总位移公式，得出三维空间下各分量及整体位移的变化值，很好地符合滑坡实际变化的特征，且两种方法得出的结果具有较好的一致性。在滑坡三维形变场提取研究中，将采用的Helmert方差分量估计定权方案和等权方案以及公式定权方案计算精度进行对比，发现Helmert方差分量估计定权方案在数据融合定权时更加科学与合理，能够有效改善计算精度。并采用双参数滑坡稳定性判定方法对部分滑坡的稳定性进行分析，显示其整体稳定状态和所处蠕变阶段，判定结果均与实际情况基本符合。基于金坪子等滑坡监测数据后验检验方法，研究滑坡变形场局部化程度与其滑动破坏过程之间的关联，提出基于局部化指标的滑坡危险性评价方法。课题有助于提高InSAR技术监测蠕动型滑坡定量危险性评价的精度和适用性，具有较高的理论意义和应用价值。