一、概况于桥水库离蓟县城东约3公里。库区位于燕山山脉边缘地带的州河盆地,四周群山环抱,地势东北高、西南低。上游各支流大部由东北流向西南。由于河流冲淤及地壳升降运动,使州河盆地广大地区有较厚的第四纪冲积洪积层。库底为黄褐色亚粘土,局部地区为黑褐色并含少量砂砾及云母片构成的一级台地。该库于1960年建成,1969年蓄水,主要 First, an overview of Yuqiao Reservoir Jixian City, about 3 km east. Reservoir area is located in the Yanshan Mountains edge of the state river basin, surrounded by mountains, terrain northeast high, southwest low. Most of the tributaries of the upper reaches flow from northeast to southwest. As a result of river scouring and crustal movements, the vast area of ​​the Zhouhe Basin has a thicker Quaternary alluvium. The bottom of the reservoir is yellowish-brown sub-clay, with dark brown in some areas and a first-class platform consisting of a small amount of grit and mica. The library was built in 1960, impounding 1969, mainly