基于数值模拟的城镇地质灾害危险性评价方法

Risk assessment on urban geological disaster based on numerical calculation

定量计算城镇尺度地质灾害不同降雨强度下的危险性是地质灾害风险评价中的难点。以红层地区群发性浅层滑坡链式灾害为研究对象,探索一种新的城镇尺度下的地质灾害危险性量化评价方法,为城镇地质灾害风险评价奠定基础。通过查询喜德县米市河区域不同降雨频率下降雨参数,统计分析国家雨量站数据及近50 a的18场群发性地质灾害降雨历时、雨型分布特征。以土层厚度、植被覆盖度及地形数据处理为基础,基于STEM TRAMM数值计算方法及降雨分布曲线计算城镇地质灾害危险性,绘制研究区地质灾害危险性评价图。通过遥感解译数据、地面调查数据及灾害数据库数据与数值计算结果对比,表明应用降雨特征统计及STEM TRAMM数值计算方法精细化评价红层地区城镇地质灾害危险性具有良好的适应性、便捷性及科学性,可为其他不同孕灾背景下的城镇地质灾害危险性评价提供思路。

Quantification of geological disasters risk at urban scale under different rainfall intensity is difficult points during geological disasters risk assessment.Taking the landslide chain disaster in cluster shallow of red bed area as a case study,the authors in this paper explored a new risk quantitative evaluation method of geological disaster at town scale to provide a foundation for the risk assessment of urban geological disaster.By querying the statistical parameters of rainfall under different rainfall frequencies in the Mihe area in Xide Town,the authors census the data of the national rainfall station and the distribution characteristics of rainfall patterns of 18 geological disasters in the past 50 years.Through the statistics of soil thickness,extraction of vegetation coverage and terrain data processing,the risk of geological disasters in cities and towns was calculated based on STEM TRAMM numerical calculation method and rainfall distribution curve,and the risk assessment map of geological disasters in the study area was drawn.Through the comparison of remote sensing interpretation data,ground survey data and disaster database data with numerical calculation results,the authors find that it has good adaptability,convenience and science of the application of rainfall characteristic statistics and STEM TRAMM numerical calculation method on fine evaluation of urban geological disaster risk in red layer area,which can provide some ideas for the hazard assessment of urban geological disasters under different disaster pregnant background.