Xin'An River

Xin'An River

This entry is compiled and applied by "popular science China" Science Encyclopedia

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Xin'anjiang was called Jianjiang and Zhejiang in ancient times,

Also known as Huigang, the upstream section of Qiantang River water system originates in Xiuning County, Huizhou (now Huangshan City), Anhui Province, and flows into the west of Zhejiang Province in the East. After the confluence of Lan River and Chunan Jiande, it becomes the Tongjiang and Fuchunjiang sections of Qiantang River, and flows into Qiantang River in the northeast, which is the main source of Qiantang River. The main stream is 373 km long, with a basin area of more than 11000 square kilometers.

Xinanjiang is rich in water resources. There are fengle and Xinanjiang reservoirs in the basin. Before liberation, its shipping from Tunxi to Hangzhou, after liberation, the reservoir cut off the route, shipping almost stopped.

Xin'anjiangsu is famous for its beautiful water. Along the river are Baisha bridge, Zhuchi, Luofeng mountain, Qiandao Lake, Meicheng, Liu Changqing villa, Shuangta Lingyun, Xin'anjiang reservoir, etc. As a national scenic spot, Xin'anjiang is known as "unique mountain and water in the world".

The origin of the name

Xin'anjiang has many names and changes in ancient times. In Hanshu geography annals, Xin'anjiang and its downstream Qiantang River are collectively referred to as "Jianjiang River". The historical records of Qin Shihuang, Xiang Yu, Shanhaijing, haineidongjing and Shuijing are all called "Zhejiang". In the Tang Dynasty, the records of Yuanhe Prefecture and county was called "Xin'anjiang". In the Song Dynasty, Yanzhou tujing was called "Xin'anjiang", a "Shejiang" and a "Huigang". The dictionary of Chinese ancient and modern place names sums up the ancient and modern names of Xin'anjiang as "Xin'anjiang, the upper reaches of Zhejiang Province, namely the ancient Jian River, also known as Shegang, also known as Huigang."

The name of Xin'an comes from the change of Xindu county to Xin'an County in the first year of Taikang (280) in the Western Jin Dynasty. And Xin'an County comes from the name of the peaks 90 kilometers west of Qimen County - Xin'an mountain, "named after Xin'an mountain.". Xin'an County is located in Chun'an, Zhejiang Province. It leads the five counties of Xin, sui'an, Xiuyang, she and she. Xin'an County was changed into Xin'an County in Sui Dynasty, belonging to Wuzhou.

General situation of main stream

Trend of main stream

Anhui Province

Xin'an River originates from wugujianshan (south of Fengcun Township, Xiuning County, Anhui Province, and Wuyuan County, Jiangxi Province, at an altitude of 1618.4 meters). It is one of the main peaks of Wulong mountain, which extends to the northwest of Huaiyu mountain. Liugujian: in the southeast of Fengcun Township, it borders Wuyuan County, with an altitude of 1629.8 meters. It is the main peak of Huaiyu mountains and the highest peak of Xiuning County. Its northeast slope is the birthplace of Xin'an River, the source of Qiantang River.

）There are two main tributaries, the South Branch is called Liushui (modern hydrology is the main source), and the North Branch is called Hengjiang, which is called Xin'anjiang after converging under the old bridge near Tunxi District. Traditionally, Hengjiang at the south end of Yi county is the main source of Xin'anjiang. It flows through Xiuning County and Shexian county to JIEKOU and into Xin'anjiang reservoir in Zhejiang Province. The main stream of Xin'an River in Anhui Province is 242.3 km long and covers an area of 6500 square kilometers, accounting for 11.9% of the area of Qiantang River Basin.

Among them:

In Xiuning County, Liushui and Hengjiang, two tributaries of Xin'an River, run through the whole area from west to East in the South and North, respectively.

In Shexian County, the main stream section named after Xin'anjiang flows from Pukou of the county to JIEKOU, Zhejiang Province, through nanyuankou, Kengkou, Zhangtan, Shendu, Xiaochuan, Sangang and Xikou. The county is 54.6 kilometers long, with a drainage area of 2585 square kilometers, a river width of 90-180 meters, a slope of 0.1 ‰, an average annual flow of 236 cubic meters per second, a total annual runoff of 7.455 billion cubic meters (1953-1957 JIEKOU station side), and silted sand and gravel in the riverbed. According to the data of Xin'anjiang reservoir hydrological station: "in 1974, the river bed at JIEKOU section of Xin'anjiang river was measured, which was 8.84 meters higher than that in 1959. The total amount of sedimentation in the reach above XIAOJINSHAN reached 1971.6 million cubic meters."

In Tunxi District, the main stream of Xin'an River is 7.53 km long, flowing eastward from Tunxi bridge to Hengjiang river. After the confluence of Liushui River and Hengjiang River, it is called Jianjiang River, and now it is called Xin'anjiang river. Xin'an River flows through the urban area and leaves xiacaoshi. The river is 9.83 km long and flows through the basin valley plain. The terrain is flat, the river bed drop is small and the water flow is gentle. The river is open and the flood period can reach 300-800 meters.

Zhejiang Province

Xin'an River flows from JIEKOU town of she county to Chun'an County of Zhejiang Province. It is called Tongjiang river when Meicheng town of Jiande city joins Lanjiang River. Fuchunjiang River when Tonglu town of Tonglu County joins Fenshui River (Tonglu County is called Tongjiang River). After the Fuchun River flows through Fuchun county to wenjiachuan and joins Qujiang River in Zhejiang Province, it is called Qiantang River. Xin'anjiang, formerly known as Huigang, Qingxi and Shegang, has a drainage area of 11047 square kilometers and a mainstream length of 365 kilometers, including 5718 square kilometers in Hangzhou and 128 kilometers in length.

Xin'an River, also known as Huigang, is located in Chun'an County, Zhejiang Province. In 1985, the investigation of Qiantang River Estuary confirmed that Xin'an River is 373 km long and 82.69 km long. The main reach is Xin'an River Reservoir area. The main tributaries are Tongxi, Liuduyuan, jiukengyuan, zitongyuan, yunyuangang, qingpingyuan and shangshangyuan.

In Jiande City, there are tributaries shouchang River and Lanjiang River. Xin'anjiang enters qinkengbu in the west of the city, flows from west to East through Xin'anjiang City District, Yangxi, xiaya, Mamu and yangcunqiao, and flows into Fuchun River after Meicheng and Lanjiang confluence. The total length of Xin'anjiang is 41.4 km, and the drainage area is 1291.44 square km.

Channel characteristics

The main stream of Xin'anjiang river flows into Shexian county from Tunxi to northeast in Anhui Province, and then flows into Xin'anjiang reservoir through the provincial boundary. Above Tunxi, there are many canyons. From Tunxi to the depth, the river is curved. The right bank is close to the mountain and the left bank is plain. The width of the river varies from 100 to 350 meters. Below the depth to JIEKOU is the narrow valley. The total drop of river bed in the province is 49.9 meters, with an average gradient of 0.64 ‰, and the average gradient from Tunxi to the depth is 0.73 ‰. The riverbed is mainly composed of pebbles with sand and bank stones. There is a river blocking dam within an average length of 2 km, which forms a channel with many shoals, shallow water and rapid flow. The water depth at the shoal is only 0.2-0.4 M.

hydrographic features

In normal years, the annual runoff into Xin'anjiang reservoir is 7.23 billion cubic meters, accounting for 15.4% of the total water in Qiantang River Basin (46.799 billion cubic meters), and the total water yield per unit area is 1.12 million cubic meters, ranking first in Qiantang River Basin. The amount of water flowing into the tributaries of Xin'an River is 1.808 billion cubic meters per year, followed by Lianjiang River and Hengjiang river. In the most abundant year, the water inflow was as high as 10.652 billion cubic meters (1954), and in the most dry year, the water inflow was 3.874 billion cubic meters (1978). According to the measured data of Tunxi station, the maximum annual average flow of Xin'an River is 199 second cubic meters, the annual total runoff is 6.278 billion cubic meters, and the runoff depth is 2351mm, which appeared in 1954; the minimum annual average flow is 4.81 billion cubic meters, the annual total runoff is 1.359 billion cubic meters, and the runoff depth is 509mm, which appeared in 1978; the interannual variation is 4.62 times, which is one of the smaller rivers in the province.

The annual distribution of runoff is more uniform than that of rivers in the whole province. The monthly maximum value appears from May to June (the main and tributaries are different, the tributaries are mostly in May, and the main and tributaries are mostly in June), accounting for about 20% of the total annual amount. The flood year can account for 35-45% of the total annual amount, which has decreased significantly since June. Therefore, the maximum water volume of Xin'an River is relatively concentrated, and its duration is also short. In the six months of the second half of the year, the monthly average water volume is less than 10% of the annual water volume, and the monthly minimum value is generally from December to January of the next year, accounting for 2-3% of the annual total.

Xin'an River is a mountainous river. The rainy season is concentrated from April to July. The flood rises and falls sharply. The duration of flood peak is short, but it occurs many times in a year, and each flood process takes 3-5 days. The flood season is consistent with the precipitation, which accounts for 65% of the annual total. According to the measured period of Tunxi station, the maximum peak discharge is 5780 second cubic meters (May 5, 1969), and the minimum peak discharge is 965 second cubic meters (May 7, 1968), with an interannual variation of 6 times. The peak discharge in normal years is 2760 second cubic meters. The measured maximum flood volume of each period in flood year is less than the total amount of normal year, which is rare in all rivers in the province. Only the maximum flood volume of 15 days and 30 days is close to and greater than the total amount of dry year, but the large multiple is also the lowest value of all rivers in the province.

The dry season is from September to march of the next year, and the amount of water in the dry season is also one of the largest rivers in the province. In the 35 years' measured data of Tunxi station, there is no water cut-off (except the water cut-off caused by section by section damming and pumping irrigation along the river in 1978). The minimum discharge is 1.09 second cubic meters, the average minimum discharge in ten days is 1.5-11.4 second cubic meters, and the average daily discharge in half of the year is 15-60 second cubic meters. This is also unique in all rivers in the province, which is obviously due to the high vegetation coverage in Xin'an River Basin and the water conservation.

Xin'an River used to be a river with little sand and clear water

Chinese PinYin : Xin An Jiang