Datong River

Datong River was named after Datong city built by the river in Song Dynasty. The upper reaches of the river have a high altitude and a large area of marshes, while the lower reaches of the river are agricultural areas near Menyuan County.

Datong River is called moele river at the boundary of Qilian and Gangcha counties, and Haomen River in Menyuan County. It is a primary tributary of Huangshui in Yellow River system. The mulishan spring (about 108 mountain springs) originated from Tuole mountain in Tianjun county is mainly supplied by atmospheric precipitation and glacier melting. It flows into the corridor between Nanshan Mountain and Lenglongling mountain, and between Datong mountain and Daban mountain. It flows into Huangshui through Qilian, Gangcha, Haiyan, Menyuan, Huzhu, Tianzhu, Yongdeng and other counties, and then flows into Minhe Xiangtang in northwest southeast direction.

Datong River

The tributary of Huangshui River, also known as Haomen River, is located in the northeast of Qinghai Province. In Song Dynasty, it was named after the construction of Datong City on the riverside. In terms of length and flow, Datong River is the source of Huangshui River. It originates from the shagaolinnamujimuling mountain between tuolainan mountain and Datong mountain in the eastern part of Qilian Mountains in Muli, Haixi Prefecture. It flows eastward through Qilian and Menyuan basins, Liancheng and Yaojie in Gansu Province, between Nanshan Lenglongling and datongshan Dabanshan in the corridor, and into Huangshui at Xiangtang in Minhe County, with a total length of 554 km.

General situation of main stream

Datong River, also known as Haomen River, is used to be a tributary of Huangshui River. It is located in the valley between Tuolai mountain, lenglong mountain, Datong mountain and Daban mountain.

The source flow of Datong River is called jiabagadangqu, which originates from zhalaizhang at the east end of Nanmu Jilin ridge in shaguolin, Tianjun county. The south-east flow passes through Muli basin, Jiangcang basin, mule basin and Menyuan basin, and gradually turns to the south-east flow below Ketu of Menyuan County, and then turns to the south to reach Xiangtang of Minhe county and join Huangshui. Datong River mainly flows through grassland and swamp above moele Township, with smooth and straight channel and wide river surface. The river course between Moeller basin and Menyuan basin is tortuous and narrow when it flows through mountainous area. The river course to Menyuan basin is wide, with many distributary channels and multi center beaches. The maximum width of river bed can reach about 2000 meters. Under Menyuan, the river mainly flows through mountainous areas, with strong undercutting, with a depth of 200-300 meters. There are many canyons, and the narrowest riverbed of the canyon is only 20-30 meters.

Datong River flows from its source to Huangshui River. Except for a small section of its downstream which flows through Liancheng and Honggu areas of Gansu Province, it is in Qinghai Province. The main stream successively flows through six counties: Tianjun, Gangcha, Qilian, Menyuan, Huzhu, Minhe. There are more than 100 tributaries, of which Yongan river is more than 50 km long, and other tributaries are relatively short. The main stream and tributaries are dominated by pinnate water system.

Datong River has a catchment area of 15130 square kilometers and a main stream of 560.7 kilometers, with an average gradient of 4.56%. In Qinghai Province, it has a catchment area of 12943 square kilometers and a main stream of 504 kilometers.

The average annual discharge of Xiangtang (3) hydrological station of Datong River from 1940 to 1979 is 90.7 m3 / s, the maximum average annual discharge is 134 M / S (1943), the minimum average annual discharge is 55.5 M / s, the extreme maximum annual discharge is 1 510 M / S (July 31, 1947) and the extreme minimum annual discharge is 7.13 M / S (January 18, 1975). The sediment concentration of Datong River is low, generally only one tenth of that of Huangshui River. The annual average sediment concentration of the main stream increases from 0.31 kg / m3 in gadatan upstream to 1.12 kg / m3 in Xiangtang (3) downstream. The average annual water temperature is 1-2 ℃ lower than that of Huangshui in the same period. The difference is large before July, and gradually decreases after August.

From 1945 to 1979, the average initial freezing date was November 14, the average freezing date was December 9, the average thawing date was March 1, the average final ice date was March 18, the average freezing days was 83 days, and the maximum ice thickness was 1.00 days.

Datong River, called jilequ in Tibetan, originated in Qinghai Province and is the boundary river between Tianzhu and Qinghai Province. The drainage area of the county is 1108 square kilometers, about 70 kilometers long, with an annual runoff of 190 million cubic meters. In the county, the tributaries of yetugou, zhuchagou, kelagou, shajingou, xianmingxia River on the left bank and sailalong, tulugou and datanzigou on the right bank flow into Yongdeng County near tiechenggou. It is the main tributary of the Yellow River.

water conservancy project

Kela reservoir is a small (second) type reservoir built in kelagou of Datong River system. The project was started in 1969 and completed in 1979. The construction was undertaken by the County Hydropower Bureau. The dam is 14 meters high and 130 meters long. The dam body is an earth dam with red clay core wall. The spillway is an open masonry gravity arch dam, which is built at the right tip of the dam. The water conveyance tunnel is a reinforced concrete prefabricated structure with an inner diameter of 80 cm. The gate chamber of the hoist behind the dam and the stilling basin are built. The storage capacity is 120000 cubic meters. In 1982, the measured silted storage capacity was 6000 cubic meters, the maximum water storage over the years was 120000 cubic meters, the designed effective irrigation area was 1200 mu, and the actual area was 834 mu. The benefit areas are Xuelong and Kela brigade of zhucha commune. In the year when the reservoir was completed, the landslide occurred in the west slope of the reservoir area, that is, the mortar masonry was used as the protection. In the autumn of 1980, the spillway drained water for more than one month, and the dam withstood the test of flood. However, the flood control standard of the reservoir does not meet the requirements, so it is an unsafe project and can only withstand the flood control capacity of once in 10 years. To reach the flood control standard, the dam needs to be raised by 0.15m. In 1981, 9.8 km of keladong main canal, a supporting project, was scrapped and rebuilt into a 15.32 km long drinking water pipeline for human and livestock, which can provide drinking water for 2262 people and 4100 livestock, and maintain 834 mu of farmland irrigation area. The normal incoming water from the upstream of the reservoir can ensure the downstream water consumption, and there is no problem of excessive storage or increasing the number of re storage.

Address: Datong Hui and Tu Autonomous County, Xining City, Qinghai Province

Longitude: 101.195202

Latitude: 37.228029

Chinese PinYin : Da Tong He