北京市密云县前火石岭泥石流沟形成条件及特征分析

Forming Condition and Characteristics Analysis on the Qianhuoshiling Debris Flow Gully in Miyun County, Beijing

北京地区现有泥石流沟856条,分布在北京北部燕山山脉和西部太行山脉一带,受地形地貌、地质条件、降雨条件以及人类活动影响较明显,总体以暴雨沟谷型泥石流为主。密云县前火石岭泥石流沟是燕山山脉一带典型的一条泥石流沟,文章在地质调查和勘查的基础上,从地质条件、地形地貌、降雨条件、人类活动等方面,综合分析前火石岭泥石流沟的形成条件及特征,同时对泥石流沟的发育情况进行深入剖析,按10年一遇暴雨强度的设计标准,在泥石流沟上游、中游、沟口3个断面计算泥石流运动特征参数,得出该泥石流沟为低易发-中等易发稀性水石流,目前处于发展阶段的停歇期,区域高强度集中降水为泥石流灾害的激发因素,泥石流的峰值流量等运动参数沿沟逐渐增大。分析结果对该泥石流沟的治理方案制定具有重要意义,对燕山山脉一带泥石流沟的防治具有借鉴作用。

There are about 856 debris flow gullies in Beijing area, located at Yanshan Mountains in the northern area of Beijing and Taihang Mountains in the western area of Beijing. Infl uenced by topography, geological conditions, rainfall conditions and human activities, the debris fl ow type is mainly rain gully debris fl ow. The Qianhuoshiling debris fl ow gully is a typical debris fl ow gully in the Yanshan Mountains. On the basis of geological survey and exploration, this paper comprehensively analyzes the forming conditions and characteristics of the Qianhuoshiling debris flow gully from geological conditions, topography, rainfall conditions and human activities, while the development of debris fl ow gully is analyzed in depth. According to the design criteria of once rainstorm in every10 years, the motion characteristic parameters of debris flow are calculated respectively in three sections of the upstream, midstream, headstream of the debris fl ow gully. We come to the conclusion that the debris fl ow belongs to the water stone fl ow and is in the rest period of the development stage at present. High intensity concentrated rainfall is the motivating factor for the debris fl ow. And peak fl ow landslides and other motion parameters gradually increase along the debris fl ow gully. The analysis of the article is of great signifi cance to the selection of the control scheme of the debris fl ow gully. At the same time, it has a reference for the prevention and control of debris fl ow along the Yanshan Mountains.