密云县位于北京市东北部的燕山脚下,地处华北平原与高原山地的过渡地带,华北地区的最大水库——密云水库坐落在我县县境中央。县境内的白河、潮河等8条主要河流自北向南流入密云水库。水库占地166平方公里,最大水面面积188平方公里,库容43.75亿立方米,于1960年建成后,在蓄水拦洪、灌溉农田和为城市提供生产、生活用水方面,发挥了重要作 Miyun County is located in the northeast of Beijing at the foot of Yanshan, located in the transitional zone of North China Plain and plateau mountains, the largest reservoir in North China - Miyun Reservoir is located in the central county. Eight major rivers such as Shirakawa and Chaohe in the county flow into Miyun Reservoir from north to south. The reservoir covers an area of ​​166 square kilometers, with a maximum surface area of ​​188 square kilometers and a storage capacity of 4,375 million cubic meters. After the project was completed in 1960, the reservoir has played an important role in water storage and flood control, irrigating farmland and providing water for urban production and domestic use