ISSN 1003-8035 CN 11-2852/P

    四川什邡市地质灾害基本特征与易发性评价

    Basic characteristics and susceptibility evaluation of geological hazards in Shifang City, Sichuan province

    • 摘要: 大比例尺地质灾害精细化调查评价工作正逐渐开展,现有易发性评价成果与实际工作有所出入,如何精准得到区域地质灾害易发性成果值得探究。为此本文以什邡市为例,基于斜坡单元逐坡开展现场调查工作并不断修正,依托调查成果进行主成分、相关性、多重共线性分析筛选出10个评价因子,通过信息量—逻辑回归模型对比分析栅格单元、斜坡单元易发性评价成果,最后以现场调查数据修编斜坡单元易发性成果。主要结论如下:(1)什邡市地质灾害整体规模较小,易发性整体上受曲率、植被覆盖率、道路影响最为明显;(2)栅格单元合理性及精度(AUC=0.876)均高于斜坡单元,但结果整体割裂琐碎难以运用,斜坡单元则存在高易发区较多及精度较差(AUC=0.825)的问题;(3)依托现场调查对斜坡单元易发性分区进行修编,得到高易发区面积占比13.48%,中易发区面积占比15.31%,低与非易发区面积占比71.21%,降低了管控难度,精度与现场调查成果相吻合。研究成果及评价流程可指导当地风险管控工作,为同类型研究提供参考。

       

      Abstract: The fine-scale investigation and evaluation of large-scale geological disasters are gradually being carried out. However, there are discrepancies between the existing susceptibility evaluation results and actual work. Exploring how to accurately obtain the susceptibility results of regional geological disasters is worth investigating. Taking Shifang City as an example, this study conducted field investigations based on slope units and continuously revised them. Based on the survey results, ten evaluation factors were selected through principal component analysis, correlation analysis and multicollinearity analysis. The information-logistic regression model is used to compare and analyze the susceptibility evaluation results of grid units and slope units. Finally, the susceptibility results of slope units were revised based on field survey data. The main conclusions are as follows: (1) The overall scale of geological disasters in Shifang City is relatively small, and susceptibility is mainly influenced by curvature, vegetation coverage, and roads. (2) The rationality and accuracy of grid units ( AUC = 0.876 ) are higher than those of the slope unit. However, the results of grid units are fragmented and difficult to apply, while slope units have more high susceptibility areas and poor accuracy (AUC = 0.825). (3) Based on the field investigation, the susceptibility zoning of slope unit is revised. The proportions of high susceptibility, medium susceptibility, and low/non-susceptibility areas are 13.48%, 15.31%, and 71.21%, respectively, reducing the difficulty of control and matching the accuracy of field investigation results. The research results and evaluation process can guide local risk control work and provide references for similar studies.

       

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