融合时序InSAR形变和LightGBM的滑坡易发性评价

Integrating time-series InSAR deformation and LightGBM for landslide susceptibility assessment

  • 摘要: 采用时序InSAR(time-series interferometric synthetic aperture radar,TS-InSAR)技术获取云阳县视向形变速率,将其分解为垂直向和斜坡向形变速率作为InSAR形变因子,结合静态孕灾因子构建LightGBM模型,进行滑坡易发性评价;采用SHAP(SHapley Additive exPlanations)算法揭示滑坡主导因素与影响机制.结果表明,云阳县28.15%区域为中等易发区,高易发区和极高易发区主要分布于长江及支流沿岸,与历史滑坡分布吻合.SHAP算法分析显示,高程、土地利用与距河流距离是云阳县滑坡发生的主要影响因素.同时,相较于传统静态模型(AUC=0.819 5,AUC全称为area under curve),引入InSAR因子后模型的AUC提升至0.830 2,说明InSAR形变信息可有效提高滑坡易发性评价精度,在滑坡易发性评价中具有重要作用.

     

    Abstract: Existing landslide susceptibility models typically rely on static predisposing factors, to effectively capture the relationship between landslides and geographic variables but neglecting dynamic features like surface deformation. Time-series interferometric synthetic aperture radar (TS-InSAR) is applied in this study to obtain line-of-sight deformation rates in Yunyang county, breaking into vertical and slope-direction components as InSAR factors. These are combined with static predisposing factors to develop a LightGBM model for landslide susceptibility. Shapley additive explanations (SHAP) algorithm is used to identify key influencing factors. It is found that 28.15% of Yunyang is moderately susceptible, with high and very high susceptibility areas concentrated along the Yangtze River, in line with historical landslide distributions. SHAP analysis highlights elevation, land use, and proximity to rivers as primary factors. Incorporation of InSAR data improves model AUC from 0.819 5 to 0.830 2, with enhanced landslide susceptibility prediction. This study confirms the significant role of time-series InSAR deformation data to improve susceptibility assessments.

     

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