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    空间异质性分区与特征因子优选对地质灾害易发性评价的影响——以辽宁省朝阳市为例

    Impact of spatial heterogeneity zoning and feature factor optimization on geological hazard susceptibility assessment: A case study of Chaoyang City, Liaoning Province

    • 摘要:
      研究目的 针对传统全局建模难以有效揭示区域灾害空间分异规律的问题,本研究提出了一种融合空间异质性分区与特征因子优选的地质灾害易发性评价方法。
      研究方法 以辽宁省朝阳市为研究区,基于灾害点空间聚类与泰森多边形构建1~4级空间分区体系,采用菲克定律_最近邻(FLA_KNN)算法筛选各子区最优特征因子子集,并结合粒子群优化的随机森林模型(PSO_RF)与麻雀搜索算法优化的支持向量机模型(SSA_SVM)开展分区易发性预测与对比分析。
      研究结果 (1)空间分区使模型精度显著提升了约7%,模型预测性能随分区数增加呈“先升后降”趋势,三级分区最优(AUC=0.8897);(2)分区特征选择模型(PFS)的平均AUC值较全局特征选择模型(GFS)与分区同特征模型(PUF)分别提升6.53%和2.26%,表明空间适配与因子优选具有叠加优势;(3)PSO_RF模型整体性能优于SSA_SVM,且在三级分区下两模型预测差异最小;(4)分区Ⅱ是灾害高易发区,受降雨量、岩体类型、地形湿度指数(TWI)及人类工程活动等共同影响。
      结论 该方法可有效提升地质灾害易发性评价精度,为区域防灾减灾与规划提供科学支撑。

       

      Abstract:
      This paper is the result of geological survey engineering.
      Objective To overcome the limitations of traditional global modeling in effectively revealing the spatial differentiation patterns of regional geological hazards, this study proposes a geological hazard susceptibility assessment method that integrates spatial heterogeneity zoning with feature factor optimization.
      Methods Chaoyang City, Liaoning Province, was selected as the study area. A 1-4 level spatial zoning system was constructed by combining spatial clustering results of hazard points with Thiessen polygons. The Fick’s Law _ K Nearest Neighbor (FLA_KNN) algorithm was then applied to select optimal feature factor subsets for each sub-region. Furthermore, a Particle Swarm Optimization _ Random Forest (PSO_RF) model and a Sparrow Search Algorithm _ Support Vector Machine (SSA_SVM) model were employed for susceptibility zoning prediction and comparative analysis.
      Results The results indicate that: (1) Spatial partitioning improved model accuracy by approximately 7%, and prediction performance exhibited a “first increase and then decrease” trend with increasing partition levels, with the 3-level partition achieving the best performance (AUC = 0.8897).(2) The average AUC of the Partition Feature Selection (PFS) model was 6.53% and 2.26% higher than those of the Global Feature Selection (GFS) model and the Partition Uniform Feature (PUF) model, respectively, demonstrating the synergistic advantages of spatial adaptation and feature factor optimization.(3) The overall performance of the PSO_RF model surpassed that of the SSA_SVM model, and the prediction discrepancy between the two models was smallest under the 3-level partitioning scheme. (4) Partition II was identified as a high-risk hazard zone, primarily influenced by rainfall, lithology, topographic wetness index (TWI), and human engineering activities.
      Conclusions The proposed method effectively enhances the accuracy of geological hazard susceptibility assessment and provides scientific support for regional hazard prevention, mitigation, and spatial planning.

       

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