北京云蒙山片区“7·16”群发性暴雨泥石流特征研究  

The Characteristics of Rainstorm-Induced Clustering Debris Flows on July 16,Yunmeng Mountain,Beijing,China

作　　者：王文 马超[1] 张志 张岩[1] 路璐 WANG Wen;MA Chao;ZHANG Zhi;ZHANG Yan;LU Lu(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Ministry of Emergency Management Big Data Center,Beijing 100013,China;Beijing Institute of Geological Hazard Prevention,Beijing 100005,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]应急管理部大数据中心,北京100013 [3]北京市地质灾害防治研究所,北京100005

出　　处：《山地学报》2022年第4期626-636,共11页Mountain Research

基　　金：北京市科技计划课题(Z191100001419015);国家自然科学基金(41702369)~~。

摘　　要：地形特征和起动条件是区域泥石流预测预报和灾害防治的基础。2018年7月16日北京云蒙山片区暴雨引发多处泥石流,但目前尚未对该区域群发性泥石流特征展开研究。本文基于地面雨量站、高分遥感影像解译和数字高程模型,对群发性泥石流的雨量激发特征、地貌发育特征和起动条件开展研究。结果表明:(1)短历时、强降雨是激发此次泥石流的主要因素,平均降雨量221.9 mm。峰值时段降雨持续3~5 h,站点平均降雨强度为48.6 mm/h,降雨强度和降雨量远超区域历史水平。(2)泥石流流域面积、沟道纵比降、陡峭程度、沟壑密度、相对切割程度以及形态系数等地形特征,表明该区域的地形地貌条件有利于泥石流形成。流域陡峭程度集中在0.3~0.65,表明该区域泥石流过程存在与洪水交互出现的特点。(3)沟谷型和坡面型泥石流的汇水面积和起动坡度存在明显差异,汇水面积分界值为0.1 km^(2),起动坡度分界值为23°。沟谷型平均起动坡度为16°,坡面型主要在25°~50°的坡度上起动。泥石流的起动坡度随上游汇水面积增大而减小,起动临界地形阈值为1.54≤SA≤5.91。该研究可为今后区域泥石流监测预警和灾害防治工程提供科学依据。A proper understanding of the topographic and the initiation conditions can support the prediction and mitigation of debris flows. Debris flow is the most typical disasters in Beijing. On July 16, 2018, a heavy rainstorm triggered clustering debris flows in Yunmeng Mountain region and its nearby hilly regions, which posed a great threaten to the safety of life and property of local inhabitants. Unfortunately, the characteristics of clustering debris flows in this area have not been studied yet. This paper examined the triggering rainfall, topographic characteristics and the initiation conditions of clustering debris flows on basis of observed rainfall records, GF images and digital elevation model. The results show that:(1) Short-duration and heavy rainfall were the main factors triggering the debris flow, with an average rainfall of 221. 9 mm. The intensified rainfall duration lasted about 3 to 5 hours and the mean rainfall intensity was 48. 6mm/h. The rainfall intensity and accumulative rainfall broke the regional historical records.(2) The morphological features such as the drainage area, longitudinal gradient, catchment steepness, gully density, incision degrees and catchment shape together illustrated that the study area was prone to debris flows. Most of the catchment steepness was between 0. 3 and 0. 65, suggesting that the formation process may be between hyper-concentrated flow and debris flow in Beijing mountains.(3) There were obvious differences in the upslope contributing area and local slope of initiation sites between gully-type and slope-type debris flow. The discriminating contributing area and initiation slope of gully-and slope-type debris flow were 0. 1 km^(2) and 23°respectively. In addition, the local initiation slope of gully-type was lower than that of slope-type. The average initiation slope of gully-type was 16° and that of slope-type was mainly concentrated in 25° ~ 50°. Topographic threshold condition could be represented by the inverse relationship between local slope and contribu

关 键 词：云蒙山 群发性泥石流 地貌特征 陡峭程度 起动条件 

分 类 号：P642.23[天文地球—工程地质学]