北京市平谷区突发性地质灾害发育特征及影响因素分析

Development characteristics and influencing factors of sudden geological disasters in Pinggu District,Beijing

平谷区是北京市突发性地质灾害较为发育的地区之一,有崩塌、滑坡、泥石流和地面塌陷4种类型。平谷区灾情和隐患主要分布在东北部镇罗营镇、熊儿寨乡、金海湖镇、黄松峪乡等中山区居民点附近和山区道路沿线,灾害集中发生在七、八月主汛期。地形地貌、地层岩性、地质构造是控制灾害的内部地质因素。陡峻起伏的沟谷、高陡斜坡和顺向斜坡是孕育地质灾害的有利地形;软硬相间的碎屑岩和碳酸盐岩地层多发育崩塌、泥石流,第四系松散土石体多发育滑坡和地面塌陷;断裂带和褶皱带附近更易引发地质灾害。切坡建房、修路等人类工程活动和强降雨是主要外部影响因素。

Pinggu district is one of the areas in Beijing with developed sudden geological disasters including collapse,landslide,debris flow,and ground collapse.The geological disasters and hidden dangers in Pinggu District are mainly distributed across the residential areas in middle mountainous areas and along mountainous roads of Zhenluoying,Xiongerzhai,Jinhaihu,and Huangsongyu in northeastern Pinggu.Disasters mainly occur in the main flood season of July and August.The terrain,lithology,and geological structure are the internal geological factors that control disasters.Steep and undulating valleys,high and steep slopes,and dip slope are favorable terrains for geological disaster development.Soft and hard alternating clastic and carbonate rocks formations are prone to collapses and debris flows.Quaternary loose soil and rock masses are prone to landslides and ground collapses.Disasters are more likely to occur near fault and fold zones.Human engineering activities such as slope cutting for house building and road construction,as well as heavy rainfall,are the main external influencing factors.