益阳市降雨型滑坡分析及预警模型构建

ANALYSIS AND EARLY-WARNING MODEL CONSTRUCTION OF RAINFALL-TYPE LANDSLIDE IN YIYANG CITY

为研究益阳市降雨与滑坡之间的关系。文中以益阳市滑坡为研究对象,运用皮尔逊相关性分析得到益阳市降雨型滑坡主要受当日及前三日降雨影响。建立了益阳市I-D降雨模型,用不同概率分布表征斜坡安全性。采用二元Logistic回归模型分别对滑坡易发性和降雨诱发滑坡的概率进行评价,最终得到了二者的概率表达式,运用熵权法得到预警模型为T=0.51H+0.49Y,根据规范QX/T—2019将危险度概念引入预警模型,最终得到预警模型公式T=0.286H+0.274Y,Ⅰ、Ⅱ、Ⅲ、Ⅳ级分别表示风险很高、风险高、风险较高、有一定风险,通过实例验证确定Ⅰ、Ⅱ预警极有可能发生滑坡,建议暴雨期间采用临时转移安置措施进行避险,对于Ⅲ、Ⅳ级预警建议暴雨期间采用“挪床行动”、“住前不住后”的避险措施。

This paper studies the relationship between rainfall and landslide in Yiyang City.Pearson product-mo⁃ment correlation coefficient shows that rainfall-type landslide in Yiyang City is mainly affected by the rainfall of the day and the previous three days.The I-D rainfall model of Yiyang City is established,and Slope safety is character⁃ized by different probability distributions.Binary Logistic regression model is used to evaluate the landslide suscepti⁃bility and the probability of landslide induced by rainfall,and a probability expression for both of them is obtained.Using the entropy weight method,the early warning model is T=0.51H+0.49Y.According to the specification QX/T—2019,the concept of risk degree is introduced into the early warning model.Finally,the early warning model formula T=0.286H+0.274Y is obtained,and GradesⅠ,Ⅱ,ⅢandⅣrespectively indicate very high risk,high risk,higher risk,and certain risk.Through the example verification,it is confirmed that the landslide is very likely to occur in warningⅠandⅡ.It is recommended to adopt temporary relocation measures during the rainstorm.For the warning of levelⅢandⅣ,it is recommended that moving the bed to another location and living in the front room of the house,not in the back room to avoid risk measures during the rainstorm.