北京市山区泥石流灾害的发育特征及预报方法探讨

北京山区泥石流灾害较为发育。泥石流分布地域广泛,但相对集中于部分乡镇、主干断裂构造带附近或几组断裂构造交汇部位、坚硬岩石分布区、末级和二级沟谷以及降雨高值区内,且多发生在7-8月份暴雨季节。受地形地貌、地质条件、降雨分布、土壤类型、气温条件以及植被覆盖程度等影响明显。对于泥石流的预报,目前主要依据的是临界雨量值。本文通过认真研究北京地区泥石流的发育规律,深入分析了泥石流的形成条件和影响因素,并在此基础上对北京地区泥石流预报方法进行了初步探讨。建立了综合考虑地形地貌、地质条件、土壤类型以及降雨情况等因素的判断公式,并就如何开展北京地区泥石流预报工作提出了建议。

Study on forecast method and developmental characteristics of debris flow in Beijing mountainous area

There are many debris flows in Beijing mountainous area. Its distribution is extensive, but relatively focusing on the part of the township, the vicinity of trunk fault zone, the intersection of different fault, the zone of hard rock, the last valley and the high value areas of rainfall. Moreover, the debris flow occurs in July and August, the rainstorm season, and it is significantly affected by the topography, geological conditions, soil type, rainfall distribution and vegetation coverage. In the current, the debris flow forecast relys on the critical value of rainfall in Beijing area. The paper analyses the formation and influencing factors of debris flow in Beijing mountainous area by studying its developmental regularity, and on the base, sets up a judgement formula considering the topography, geological conditions, soil type and rainfall distribution, and makes recommendations on how to forecast a debris flow.