北京市门头沟区泥石流灾害分布及临界雨量研究

Study on the Distribution of Debris Flow Disaster and Critical Rainfall in Mentougou District,Beijing

泥石流的发生受各种因素共同影响,确定泥石流临界雨量是突发地质灾害预警预报工作的一项重要内容,探索新方法用于泥石流临界雨量计算也是目前突发地质灾害预警预报工作的需求。本文分析了门头沟区泥石流灾害分布特征和影响因素,在前期研究基础上,以灾害频率与降雨频率分析方法计算了不同时间段泥石流临界雨量阈值,结果显示:门头沟区特殊的地质条件构成了泥石流形成的物源与地形基础,降雨是泥石流的激发因素,根据泥石流发生时的历史雨量监测数据,计算得出的临界雨量值均小于历史雨量监测数据。本研究推荐的门头沟区泥石流不同时间段临界雨量阈值可用于北京市泥石流灾害预警预报工作,研究结果可为北京市泥石流灾害预警预报工作提供科技支撑。

The occurrence of debris flow is affected by various factors. It is an important part of the early warning and fore- casting of geological disasters to determine the critical rainfall of debris flows. The exploration of new methods for critical rain- fall calculation of debris flows is also a demand for the early warning and forecast of geological disasters. This paper analyzes the distribution characteristics and influencing factors of debris flow disasters in Mentougou District. Based on the previous studies, the critical rainfall threshold values of debris flow at different time periods are calculated using the frequency of disas- ters and frequency of rainfall analysis. The results show that the special geological conditions in Mentougou District constitute the formation of debris flows. Based on the provenance and topographic basis, rainfall is the triggering factor of debris flow. According to the historical rainfall monitoring data during the occurrence of debris flow, the calculated critical rainfall values are all smaller than historical rainfall monitoring data. The threshold of critical rainfall at different time periods in the debris flow in the Mentougou area recommended in this study can be used for the early warning and forecast of debris flows in Beijing. The research results can provide scientific and technological support for the early warning and forecasting of mudslides in Bei- jing.