考虑滑坡活动性的金沙江上游白玉−巴塘段滑坡易发性评价

    Landslide susceptibility evaluation in the Baiyu-Batang section of upper Jinsha River considering landslide activity

    • 摘要:
      研究目的 基于滑坡活动性,优化滑坡样本,提高滑坡易发性评价准确性。
      研究方法 金沙江上游地形地貌复杂、构造活动强烈、滑坡灾害发育,选取金沙江上游白玉-巴塘段为重点研究区,采用遥感解译、InSAR形变探测、野外调查等技术方法,查明并分析了滑坡活动性。将滑坡划分为A(活动性滑坡)和B(活动性滑坡+非活动性滑坡)2个数据集,选用高程、坡度、坡向、工程地质岩组、到断裂距离、地震动峰值加速度、到河流距离、NDVI八个因子指标,采用加权信息量模型完成滑坡易发性评价。
      研究结果 结果表明:基于A、B数据集的AUC分别为0.855和0.810,说明取得了较好的滑坡易发性结果,滑坡极高、高易发区主要集中分布于金沙江、降曲等河流沿岸的若干区域,且明显沿水系线状分布,中易发区主要分布于纵向谷岭之间的区域,低易发区主要分布于地势平坦的区域。
      结论 基于A数据集的滑坡易发性精度高于B数据集,且极高、高易发区的识别有所提高,考虑滑坡活动性可以有效提高滑坡易发性评价模型的准确率。滑坡活动性是滑坡易发性评价需要考虑的重要因素,提出的研究思路和评价方法为推进高山峡谷地区的滑坡易发性研究提供了重要参考。

       

      Abstract:
      Objective This paper optimizes landslide samples based on landslide activity to improve the accuracy of landslide susceptibility evaluation.
      Methods The terrain and landforms in the upper of Jinsha River are complex, with strong tectonic activity and the developed landslide disasters. The Baiyu−Batang section of the upper Jinsha River is selected as the key research area, and remote sensing interpretation, InSAR deformation detection, and field investigation techniques are used to identify and analyze landslide activity. All landslides were divided into two datasets: A (active landslides) and B (active landslides and inactive landslides). Eight factors, such as elevation, slope angle, slope direction, engineering geological units, distance to fault, seismic peak ground acceleration, distance to river and NDVI, were selected to complete the landslide susceptibility evaluation by weighted information model.
      Results The results show that the AUC based on A and B datasets are 0.855 and 0.810, respectively, indicating that satisfied landslide susceptibility results have been achieved. The very high and high landslide susceptibility is mainly distributed along the Jinsha River and Jiangqu River, and show an obvious band distribution trend along water systems. The middle landslide susceptibility is mainly distributed in the areas between the longitudinal valleys, and the low landslide susceptibility is mainly distributed in flat areas.
      Conclusions The accuracy of landslide susceptibility based on A dataset is higher than that of B dataset, and the identification ability of very high and high landslide susceptibility areas is relatively improved. So, landslide activity can effectively improve the landslide susceptibility accuracy, and is an important factor to be considered in the landslide susceptibility evaluation model. The proposed study ideas and methods provide an important reference for promoting landslide susceptibility evaluation in alpine gorge areas.

       

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