(1) Major rivers in Qingdao

There are 224 rivers in Qingdao, all of which are rain sources in the monsoon region, and most of them are independent streams entering the sea. There are 33 large rivers with basin area exceeding 100km2.

1. Dagu River and its tributaries

Dagu River Basin is located in the west of Jiaodong Peninsula, with east longitude of about120 30 ′ ~120 25 ′ and north latitude of about 3610 ′ ~ 3712 ˊ. The total area of the basin is 6 13 1.3km2, and its trend is roughly the same as that of the main stream. The northern part of the basin is mountainous and hilly, and the southern part is piedmont plain and plain depression. The terrain is high in the north and low in the south, and the terrain slope gradually slows down from north to south. Originated in a mountain stream 500 meters west of the foot of Fushan Mountain in Zhaoyuan City, it flows from Zhaoyuan North to South and enters Laixi City in the north of Xijujia Village in Malianzhuang Town. It flows into Qingdao from north to south, passes through Laixi, Pingdu, Jimo, Jiaozhou and Chengyang, and enters the sea in South Wharf Village of Jiaozhou. The mountainous area, hilly area1527.6km2, plain area 1705. 1km2 and depression area 80 1.2km2 account for1.4 of the basin area respectively. The basin covers Laizhou, Zhaoyuan and Laiyang in Yantai City. Part of Laixi City, Qingdao and Pingdu, Jiaozhou, Jimo and Chengyang. Qingdao section of Dagu River is the largest river in Qingdao, with a drainage area of about 6067.5km2 The water system includes main stream and tributaries. The main tributaries are Xiaogu River, Guwu River, Liuhao River and Nanjiaolai River, which is called Qingdao Mother River.

Figure 4- 1 Schematic Diagram of Distribution of Main Rivers in Jiaodong Peninsula

2. The main stream of Jiaolai River and its tributaries

Jiaolai River is located between Yi Mountain Range and Kunyu Mountain Range in Jiaodong Peninsula. It is about119 30' ~120 6' east longitude and 3612' ~ 37 6' north latitude. The total length of the main stream is 130km, with a total drainage area of 5478.6km2, in which the length of Beijiaolai River is 100km, with a drainage area of 3978.6km2, and the length of Nanjiaolai River is 30km, with a drainage area of 1500km2. Jiaolai River passes through Changyi, Laizhou, Gaomi, Zhucheng, Pingdu, Jiaozhou and Jiaonan in Qingdao. The basin is rectangular, with a long north-south trend, and the river runs southeast-northwest. The maximum width of the basin is 64 kilometers and the minimum width is 8 kilometers. All tributaries are orthogonal to the mainstream, forming a pinnate water system. The water flow in Jiaolai River basin is generally concentrated from the watershed on both sides to the main stream. There are many plains in the basin, with accumulation landform as the main feature. Erosion and alluvial platforms account for about 75% of the basin area. The landform formed by volcanoes accounts for about 7%, and the hilly area 18%. Hilly areas and erosion platforms are distributed in the middle and upper reaches of tributaries, and alluvial platforms are distributed on both sides of the main stream. The annual rainfall in the basin is mostly concentrated from June to September, and there is a big difference between flood season and dry season. The tributaries with the total basin area exceeding 100km2 are Zehe River, Ziyang River, Baili River, Changping River, Baisha River, Sanmiaojia River, Wanglonghe River, Xianhe River, Jiaohe River and Moshui River.

Besides, only the rivers that flow into the sea are Baisha River, Moshui River, Wang Ge Zhuanghe River, Baima River, Liji River, Zhoutuan River and Yanghe River.