Yongjiang

Yongjiang

Yongjiang River, known as Dajia River in ancient times, flows into the sea alone in the East China Sea. It is one of the eight major water systems in Zhejiang Province. Because Ningbo is called Yong for short, it is named Yongjiang.

It is 133 km from yaojiangyuan to Zhenhai estuary and 118.7 km from Fenghua estuary, with a drainage area of 4518 square kilometers. There are two branches of Yaojiang River and Fenghua River in the upstream, with Fenghua River as the main source and rising from Xiujian mountain in the east foot of Siming Mountain; Yaojiang River as the main source and rising from the west slope of Miangang mountain in the northeast of xiajialing mountain in Siming Mountain; it flows through Fenghua District, Yinzhou District and Haishu District, converges with Fenghua River and Yaojiang River in Sanjiangkou of Ningbo City and flows into the East China Sea in zhenhaikou of Ningbo City. The Yongjiang River, which is the main trunk of Yaojiang River and Fenghua River, converges at the Sanjiangkou of Ningbo City to the exit of xiaoyoushan and xiaoyoushan in Zhenhai city, with a total length of 26 kilometers and a drainage area of 361 square kilometers.

Composition of main stream

The Yongjiang river system is composed of two primary tributaries (river source) of Yongjiang River, Yaojiang River and Fenghua River, and four secondary tributaries (Shanjiang River, Xianjiang River, Dongjiang River and Yinjiang River) in the upper reaches of Fenghua River, as well as plain river network. Plain river network is mainly composed of urban river network, Yinzhou river network, Zhenhai river network, part of Beilun river network and Cixi river network. The main stream of Yongjiang river system generally refers to Fenghua River, Yaojiang River and Yongjiang river. Yao Jiang is the main source of Ningbo Chronicles

. Fenghua river is the main source of Zhejiang hydrology.

Yao Jiang

Yaojiang River, also known as Shunjiang River and Shunshui River, is mainly originated from liangnongxi. Its source, the west slope of Miangang in the northeast of xiajialing, Siming Mountain, is a stone tablet carved with five big characters in bold script of "Zhengyuan of yuyaojiang River". Seven thousand years ago, our ancestors brought water and dug wells to Hemudu on the edge of the Yao River, where they multiplied and bred a splendid Hemudu civilization.

Lianglong river runs northward to Siming lake reservoir, goes out of the reservoir to Xinjiangkou, which is called Siming river. After Xinjiangkou meets Tongming River, it is called Yaojiang River. From the west to the East, it flows to Heshu River, mazhuzhong River, Xijiang River, Zhongjiang River, Dongjiang River and cijiang River in the north, and to Fengcun, nanmiao, Lubu, Chepeng and Dayin rivers in the south, zigzagging to Wantou, where Yaojiang sluice is built. The gate is 3.3km away from Fenghua River and converges with Sanjiangkou in Ningbo. The total length from the source to Sanjiangkou is 107.4 km, with a drainage area of 1934 square kilometers.

Yaojiang River is a flat prototype river with flat riverbed, winding and slow flow. The length of the section from Xinjiangkou to Yaojiang sluice is 79.1km, the water surface gradient is less than 0.01 ‰, the river width is 50-150m, the widest part is 250m, the average water depth is about 5m, and the normal water storage is about 24680000m3.

Fenghua River

Fenghua River, the main source of Shanjiang River, its upstream called Huixi, originated from dongjiayan village, dawanggang, east foot of Siming. Huixi flows to Tingxia village, where there is Tingxia reservoir. It flows out of the reservoir to Gongtang, which is called Shanjiang River after Kangling river. The upstream river is 36.3km long, with an average slope of 20.83 ‰ and a width of 20-120m. It flows eastward from Gongtang to xiaowangmiao, passes through the channel head of Tingxia reservoir, and then flows eastward to Jiangkou. Xianjiang River and Dongjiang River flow in from the right bank, and reach 900m below Fangqiao. Yinjiang river flows in from the left bank, which is called Fenghua river The river is 30.4 km long, with a slope of 0.54 ‰ and a width of 50-220 M. from Fangqiao to Sanjiangkou in Ningbo, the river is a tidal reach with a length of 26.4 km, a width of 130-220 m, an average depth of 5 m and a slope of 0.01 ‰.

The Fenghua river is 93.1 km long with an average slope of 8.1 ‰ and a drainage area of 2223 square kilometers.

Yongjiang Ben Gan

Yongjiang River is formed by the confluence of Fenghua River and Yaojiang River. The section of Yongjiang River below Sanjiangkou in Ningbo city is commonly known as Yongjiang River, also known as Dajia River. About 6000 years ago, Fenghua River and Yaojiang River formed one after another with the retreat of sea water, and merged into Yongjiang River at the Sanjiangkou of Ningbo City. The coastline of Yongjiang River is in the area of jinshanguntang, where Yongjiang River enters the sea, about 8 km away from Sanjiangkou. 4000 years ago, with the continuous retreat of sea water and sediment deposition, the coastline extended to Zhenhai area, and Yongjiang River also extended, and the distance from the estuary to Sanjiangkou is 3 km In 1974, the waters between Zhaobaoshan, hutushan and Dayou mountains were filled with rubble, and a new Zhenhai Harbor was built. In 1978, the Zhenhai harbor block dike was built,

In 1983, the diversion dike outside Youshan was built, and the north bank was extended by 3.6 km to the outside of dayuanshan. The Yongjiang river reach below Sanjiangkou is 25.6 km long. Yongjiang River is 133 km long from Yaojiang River source to Zhenhai estuary, 118.7 km long from Fenghua river source to estuary, with a drainage area of 4518 square kilometers.

There is a diversion dike in the north bank and a spur dike in the south bank. From Sanjiangkou, the south bank is Jiangdong North Road in the old urban area, passing Meixu to Yaqian and Xiaogang; the north bank is the Bund and Baisha on the North Bank of the old urban area, passing kongpu and qingshuipu to Zhenhai Chengguan.

hydrographic features

There are 8 bends and 6 shoals in Yongjiang River Road, especially in Sanguantang of Zhenhai and Meixu section of Yinxian County, which is opposite to the river. The estuary is trumpet shaped with obvious tidal phenomena. The water surface area of the river channel is 14 square kilometers, the average width of the river is 408 meters, the average water depth is 5.72 meters, the average width of the middle tide level is 290 meters, the average section area below the middle tide level is 2560 square meters, and the flood discharge capacity is 2500 cubic meters per second. In 1959, after the construction of Yaojiang sluice, the tidal flow of 12 million cubic meters upstream of Yaojiang River was intercepted, the tidal water was blocked, and the tidal flow decreased sharply. The tidal inflow of zhenhaikoumen section decreased from 36.1 million cubic meters to 21.6 million cubic meters, and the tidal inflow of Baisha section in the old urban area decreased from 26.3 million cubic meters to 13.3 million cubic meters, which led to the deposition of Yongjiang mainstream. From July 1959 to May 1973, the total amount of sediment deposition in the river channel was 22.68 million cubic meters, the average river width was reduced to 355 meters, the ice depth was reduced to 2.14 meters, the average section area below the middle tide level was reduced to 1536 square meters, and the flood discharge capacity was reduced to 1500 cubic meters per second. The flood level in the old urban area has been raised by 50 to 70 cm, affecting navigation and flood discharge. Dredging began in 1961. After 1973, the annual siltation decreased to about 200000 cubic meters, the change of erosion and siltation in the main stream section tended to be stable, and the riverbed and tidal flow were in balance again. The average high tide level of Yongjiang River is 1.17 meters above the zero point of Yellow Sea, the highest tide level is 2.98 meters in 1981, the average low tide level is minus 0.52 meters, the lowest tide level is minus 1.72 meters in 1959, the average tidal range is 1.70 meters, and the maximum tidal range is 3.62 meters in 1961.

Main tributaries

Xianjiang, a tributary on the left bank of Fenghua River, is called Zhenting River in ancient times. It originates from dagong'ao, the first peak at the junction of Fenghua, Xinchang and Ninghai counties. It is named Xianjiang because it flows through Fenghua county. It flows from the southwest to the northeast, converges with the water from Wanzhu Township through Dayan and nanxikou, and then twists and turns to the northeast to Hengshan Reservoir, with a slope of 14.3 ‰ and a river width of 30-120 meters; the water from Aodi comes out of the reservoir, flows through Louyan, and then flows into Zhangjiatan and yinjiakeng from the left bank, with a slope of 3.45 ‰ and a river width of 70-120 meters; it flows through Shangtian, Fenghua County, Nandu, Fangqiao and Dongjiang After confluence, the river flows into Fenghua river at the mouth of Sanjiang River 900 meters below the square bridge, with a slope of 0.67 ‰ and a river width of 60-150 meters.

Yinjiang river is a tributary on the left bank of Fenghua river. It is called Zhangxi above the weir. The main stream of Dajiao river originates from the piedmont of baituchanggang in the upper reaches of Tangtian in Siming Mountain area, converges with the water from Lizhou through Beixi, flows northward through Daheng mountain to Banling, turns East, and flows between the zigzag and steep valley, flows from huizhiling on the left, and flows to Zhougongzhai from Diping and gaobaiyan on the right, with a slope of 21.74 ‰ and a river width of 100-130 m; then zigzags northward through du'ao to Miyan and Xiaojiao River, where the Jiaoxi river is built Kou Kou reservoir is 43.9 km long and has a drainage area of 259 square km. It is 16.1 km long from Jiaokou reservoir to talongwang River, Huanxi River and Qingyuan River to tashanyan with a slope of 2 ‰ and a width of 80-130 M. below tashanyan, there is a tidal reach flowing eastward to hengzhang and into Fenghua River with a length of 9.4 km, formerly known as Lanjiang River or Yinjiang river with a slope of 0.48 ‰ and a width of 90-110 M.

Shanjiang river is a tributary (source) on the left bank of Fenghua river. It originates from xiujianshan mountain at the eastern foot of Siming River and reaches Gongtang of Banxi Township, which is called Xihui river. In 1985, the Tingxia reservoir was built in xihuixi, with a controlled catchment area of 176 square kilometers. Shanyuan River, which originates from laoanji mountain in Xinchang, converges at Gongtang, and is called Shanxi river. In the East, it reaches xiaowangmiao town. Now, a weir is built to block the upstream water from entering Tingxia reservoir. It flows through Dongjiang inverted siphon to Jiangshan in Yin County, and through yueyuwangling tunnel to Daqi and Chaiqiao in Beilun District. The main stream of Shanxi river flows out of xiaowangmiao Town, which is called Shanjiang river. It flows through Jiangkou and Fangqiao to Huidong river near Xiejia, and then flows into Fenghua river. It flows from southwest to northeast, with a length of 75.5 km and a catchment area of 454 square kilometers. In the old days, the section from Jiangkou to xiawangdujiang was also called Huijiang. From the Song Dynasty, Yuan Dynasty to the early Ming Dynasty, the rivers flowed freely, and the river sections below Gongtang could be rowed. After that, soil and water loss became serious and silted up gradually. Today, the tidal reach below xiaowangmiao town is still navigable. The tidal boundary is near dabutou, Fenghua. In dry season, the salt tide goes up to Jiangkou Town.

Dongjiang River is a tributary on the left bank of Fenghua river. It originates from nanbodaolinggang, ge'ao Township, Fenghua. Its upstream is called Baixi, also called Paixi. It meets Zhuxi in front of Sunjia village, Shangtian, and is called Dongjiang River. It flows through Dongqiao, Xiwu, Baidu, to Naxian river of Fangqiao Town, and to neisanjiangkou near Xiejia in the north, where it joins with Shanjiang River in the West

Chinese PinYin : Yong Jiang