降雨引发斜坡破坏的阈值是地质灾害预警的基础.文章以2004-2019年白龙江流域甘肃段5个县区内因长期强降雨引发的滑坡作为研究对象,采用频数法研究不同岩性特征的滑坡降雨预警阈值.构建了不同概率等级下,引发滑坡的事件降雨量(event rainfall)与降雨历时(duration of rainfall)之间的关系模型,并给出了下限临界累计降雨阈值.通过2020年陇南武都区暴洪灾害引发的滑坡特征及降雨数据验证,滑坡前雨量计监测获得的累计降雨量与模型给出的临界累计降雨阈值基本相符,对持续强降雨引发的滑坡灾害的预警具有指导意义.
Study on rainfall threshold of different lithologic landslides in Bailong River Basin of Gansu Province
The research results regarding the threshold values for slope disasters caused by rainfall are crucial for geological disaster prevention.In this study,landslides induced by long-term heavy rainfall occurred in five counties within the Gansu section of the Bailongjiang Basin between 2004 and 2019.Using the frequency method,the rainfall thresholds for early warning of rainfall type landslides with different rock characteristics were investigated.A relationship model between event rainfall and the duration of rainfall leading to landslides was constructed under different probability levels,and a lower threshold for critical cumulative rainfall was provided.Through verification of landslide characteristics and rainfall data resulting from a flash flood disaster in Wudu District in 2020,the accumulated rainfall measured by the rainfall gauge before the landslide is found to be consistent with the threshold given by the model.This finding is of guiding significance for early warning of landslide disasters caused by sustained heavy rainfall.
Bailongjiang Basingeological hazardsmeteorological risk early warningearly warning model research
万方数据
维普
