基于有效降雨强度的滑坡灾害危险性预警

选取湖北省恩施地区1 000 km2区域作为典型研究区, 在全面分析该区域历史滑坡资料的基础上, 根据该区滑坡生成与地层岩性之间的关系, 将研究区地层划分为高、中、低3类易发性岩组.分岩组统计降雨监测数据与历史滑坡信息, 得出有效降雨强度与关键降雨持续时间的散点图, 由此确定不同滑坡发生概率的有效降雨强度阈值, 提出该区的滑坡灾害危险性预警判别模型.基于样本区统计数据建立滑坡预测指标体系, 运用GIS得出研究区域的滑坡空间易发性区划结果, 并根据不同易发岩组-有效降雨强度模型, 叠加滑坡灾害易发性分区结果与降雨危险性预警等级分级结果, 对研究区的滑坡灾害危险性进行了预测预警.结果表明: 不同易发岩组-有效降雨强度模型所得预警结果与实际情况吻合, 预警模型具有考虑全面和预警精度高的特点, 在实际预警中切实可用. 

Landslide Hazard Warning Based on Effective Rainfall Intensity

A region of 1 000 km2 in Enshi, Hubei Province is chosen as the typical study area, and its historical landslide data are comprehensively analyzed in this paper. The strata in the study area are divided into three types including high, middle and low susceptible petrofabrics according to the relationship between local landslide formation and lithology. The scatter diagrams about effective rainfall intensity and critical duration are obtained based on rainfall monitoring data and historical information of landslides in each petrofabric. Thus effective rainfall intensity thresholds are determined and landslide hazard warning model of the study area is suggested. In this study, landslide prediction evaluating system is firstly established based on data of sample area, and then landslide susceptibility distribution map is obtained by using GIS. According to Different Susceptible Petrofabric-Effective Rainfall Intensity Models, the landslide hazard warning is realized by overlaying landslide susceptibility distribution map and rainfall risk grade distribution results. Results show that the hazard warning results fit well with the actual situation. Thus, the warning model is verified to be effective, accurate and comprehensive to provide scientific evidence for preventing and reducing disasters.