泥石流、滑坡是北京山区常见的山地灾害，尤以泥石流灾害最为严重。全市共有泥石流沟700条，分布在房山、门头沟、昌平、怀柔、延庆、密云、平谷7个区县，涉及乡镇61个。泥石流、滑坡多次造成人员伤亡和财产损失。防治泥石流、滑坡灾害，对改善北京山区环境，保护首都水源地等都有着重要意义。

Debris flow and landslide are two types of common disasters in the mountain area of Beijing city, and among which debris flow is especially serious. There are 700 debris flow gullies dist ributed over 61 villages and towns of districts and counties of Fangshan, Mentougou, Changping, Huairou, Yanqing, Miyun and Pinggu. The heavy incidents of personal injuries and deaths, and properties losses from debris flow and landslide have occurred many times there. The action is of great significance for improving environment and protecting the source of water supply of Beijing city.