Daxia River

Daxia River

Daxia River, a tributary of the Yellow River. The ancient name of Lishui, or "sangqu" in Tibetan, originated from the northern and southern foothills of dabulekha mountain on the Gannan plateau at the junction of Gansu and Qinghai. Sangququeka in the South and danaang in the north are called Daxia River after confluence. It flows through Xiahe County, Linxia County, Linxia city and Dongxiang County, and then flows into Liujiaxia reservoir of the Yellow River. It has a total length of 203 kilometers and a drainage area of 7152 square kilometers. The main tributaries are Luo river, tielonggou River, laoyaguan River, datan River and Oxford river.

In history, the Daxia river was damaged by rainstorms and floods in the upper reaches of the river, which caused damage to people's lives and property several times. After the founding of the people's Republic of China, the party and the people's government actively carried out comprehensive management, built water conservancy projects, built embankments and dams, and now it has become a river system for the benefit of local people and coastal residents.

< I business card picture: Linxia county section 1 of Daxia River < / I

General situation of main stream

Daxia river was called Lishui River before Ming Dynasty. Originally, Daxia River referred to Guangtong River, a tributary of Taoshui river. Later, it was mistakenly named as "Lishui River is fifteen miles southeast of Lanzhou" in the unified annals of Ming Dynasty, and it was mistakenly named as Daxia River and handed down.

Daxia river originates from dabulekha mountain, which is located at the junction of Gansu and Qinghai provinces in Gannan plateau. It flows from southwest to northeast, through Xiahe County, Linxia County, Linxia city and Dongxiang County of Gansu Province, and then flows into Liujiaxia reservoir of the Yellow River. The total length is 203 km

(1) 176 km

）The drainage area is 7152 square kilometers (5409 square kilometers)

）。

Trend of main stream

Daxia river originates in Xiahe County. In Xiahe County, the birthplace of Daxia river is located in dabuleheca mountain (dariheka mountain) on the border of Gansu and Qinghai in the southwest of Xiahe County

）。 The upper reaches of the mountain have one branch in the South and north of the mountain: South source sangququeka, which comes from the southeast side of jiaweiyeka, 4221 meters above sea level, in the west of Xiahe County, Gansu Province. The Northeast flow converges with the North source. The North source is duowa River (danaang and Dannang). The North source comes from the southeast side of Gulang temple in the south of Tongren County, Qinghai Province, with an altitude of 4281 meters. After flowing northward, it turns to the East and enters Xiahe County, Gansu Province. After converging in Sangke Township, Xiahe County, it is called Daxia river. (according to some data, the upper section of Xiahe river is called Xiahe River, which is called Daxia river only after wangatan of wanggetang town of Xiahe County joins Luohe River.

）。 It is generally believed that sangququeka in Nanyuan is the main source (Xiahe County annals)

）。 It flows through Sangke Township, Labrang town and Damai township of Xiahe County from southeast to northeast. It turns northward in huiluo river of wanggetang Town, then passes through Madang Township and qu'ao Township, and then leaves the country at tumenguan and crosses Xiahe County. The length of transit is 85.3 kilometers, the catchment area is 1692 square kilometers, and the drainage area is 5409 square kilometers, accounting for more than 2 / 3 of the county area. All the way, it converges with the tributaries of Dawa River, Ge River, Yangqu River and Qingshui River. It is the longest river in the county. Its main tributaries are duowa River, Gehe River, Ganjia River, Qingshui River and Qilong river.

The Daxia River excavated from Menguan enters the Linxia Basin, where duozhiba River from south to north, monigou River from north to south, Yinji Township, huaishuguan River from west, laoyaguan River from north to south, Xinji Town, Yulin River on the right, Luhan town on the right, Chengguan town on the left, Hongshui River on the left, Oxford River on the right, and the following is the basic information The boundary river between Linxia county and Dongxiang County flows northwestward at Dongxiang township of anjiapo to Lianhuatai village of Lianhua town (Kangjiawan) and flows into Liujiaxia reservoir. Linxia Prefecture has a drainage area of 1543 square kilometers, a flow of 58 kilometers, and a river gradient of 9.6%.

At the mouth of the Daxia River, lianhuacheng and lianhuabao, the old county seat of Yongjing County, are on the right bank, and Hetan Town, Dongxiang Autonomous County, is on the other bank. In 1900, lotus fort was built in the delta of the Daxia River into the Yellow River. The Lotus Village of lamachuan was set up in 1370, the third year of Hongwu in Ming Dynasty, and the site of the village was moved to jiantuchuan in the end of Ming Dynasty. Lotus ferry was set up in 1897. In 1929, Yongjing county was set up in Linxia County, and lianhuabao was the county. The county is the center of politics, economy, culture and transportation. On August 28, 1949, Wang Zhen led a hundred thousand troops across the Yellow River, with a commemorative sign. On December 20, 1958, Yongjing county was incorporated into Linxia city (later Linxia Prefecture), and Lianhua city was the residence of Lianhua people's commune. In December 1961, the organizational system of Yongjing county was restored, and the government station was moved to Xiaochuan, Liujiaxia. In 1967, the Liujiaxia reservoir area was filled with water, and all the government facilities were removed. On October 28, the castle was submerged by Liujiaxia reservoir, and the lotus ferry was moved up. It is still the main water transportation road between Linxia and Yongjing.

Channel characteristics

The main stream of Daxia River in Xiahe County belongs to the middle and upper reaches. The south of tumenguan is the upstream. The upstream is about 50 km from Heyuan to Sangke grassland. Due to the wide slope and valley, the flow is slow. The middle reaches is 85.3 km from Sangke to tumenguan. Due to the inconsistency of structure and lithology along the flow area, the geomorphic characteristics of wide valley and gorge are formed. Floodplain is often formed at the place with low anti scour force. In the section with hard rock, the igneous rock of Triassic system is exposed, which often forms a gorge by flowing water. The riverbed gradient is very large, and there are rapids and dangerous shoals in it. The rock at the bottom of the river is uplifted, and the water potential is turbulent. Although the valley is eroded and cut by the current all the year round and scoured by the flood, the trench tends to become deeper and lower, but the vegetation on both sides is good, the trees are beautiful, and the scenery is pleasant. The difference between the middle reaches is 82 meters, with an average slope of 9.6%; the altitude is more than 2500 meters, and the climate is humid and cold. Except for a small amount of trees in Taizishan, the rest are grasslands in Gannan Tibetan Autonomous Prefecture.

From the north of tumenguan to the entrance of the Yellow River is the lower reaches, about 40 km. The altitude of the entrance of Daxia river is 2105 meters, and the altitude of the confluence is 1735 meters. Through the Loess Plateau, there are many gullies, poor vegetation, heavy rain, debris flow and landslides. However, the agriculture in the wide valley area of Daxia river is developed, and the intersection of Daxia river with duozhiba River and huaishuguan river forms Diaoqi and yinjichuan. Shuangcheng joins laoyaguan River, and then joins Hongshui River and Oxfordshire River, forming Dongxi Nanchuan with the largest area, convenient population and water conservancy. The width of the river is 273-530m, with the maximum of 1000m.

The river flow is gentle, which is the lifeblood of agricultural irrigation and drinking water for human and livestock in Linxia area.

Beiyuan, Yongle and other irrigation channels, each in more than ten thousand mu. There is also a reservoir of more than one million cubic meters. Hui, Han, Dongxiang and other ethnic groups are mostly engaged in farming and business, and have a rich life.

hydrographic features

According to the measured data of Xiahe hydrological station, the average annual discharge of daxiahe county section is 9.44 m3 / s, and the average annual runoff is 312 million m3. The average annual precipitation of the basin is 444.4 meters, and the spatial and temporal distribution is uneven. The precipitation is mainly distributed in July, August and September, and mostly in the form of high-intensity rainstorm or continuous rainfall, with short duration and high intensity.

According to the data of Xiahe County in the upper reaches, the annual average runoff of Daxia river is 3.12 cubic meters, the annual average runoff is 9.89 cubic meters per second, the measured maximum runoff is 40 cubic meters per second, the minimum runoff is 1.66 cubic meters per second, the annual average sediment transport is 129000 tons, and the annual erosion modulus is 467 tons per kilometer. Due to the influence of global climate change, the discharge of Daxia river is obviously decreasing.

The measured maximum discharge of fengjiatai hydrological station is 960 m3 / S (August 10, 1979), the minimum discharge is 1.37 m3 / S (May 10, 1996), the maximum peak discharge in history is 1390 m3 / S (1914), and the average annual velocity is 1-28 M / s. The annual sediment concentration is 3.49 kg / m3, the sediment transport rate is 133 kg / s, and the sediment transport is 4.192 million tons / year.

Main tributaries

Duowa River, also known as Dana Pleiades, originates in dabuere, Southeast of Tongren County, Qinghai Province. Most of its main streams are in Tongren County, from west to East, to the north of Sangke Township, Xiahe County, and flows into Daxia river. It has a total length of 55 kilometers, a drainage area of 751 square kilometers (875 square kilometers within the county), and an annual runoff of 126 million cubic meters.

Ganjia River, which originates from qunwulegeng mountain on the border of Gansu and Qinghai in the west of Ganjia Township, Xiahe County, has a total length of 57 km and flows through Ganjia, Qilong and Madang townships. The estimated annual runoff is 147 million cubic meters, the average annual flow is 4.67 cubic meters per second, and the water energy reserve is 25000 watts. It flows into the Daxia River in front of Madang township.

Qingshui River, also known as qu'aoqu, originates at the foot of Dalijia mountain in Ganjia township of the county. It gathers qu'aoqiangwa and xi'aolongwa near ayitang, flows southeast through Ganjia and qu'ao townships, and joins Daxia River in front of qu'ao township. It has a total length of 23 kilometers, a catchment area of 111.4 square kilometers, a measured annual runoff of 22 million cubic meters and an average annual flow of 0.70 cubic meters per second.

Gehe (Luohe, Yongqu) originates from lalidashan at the junction of zogaiduoma Township in Hezuo City, with an altitude of 3802 meters. Maidai, Nawu Township, flows through zogaiduoma Township, zogaimanma Township, kajiadao Township, kajiaman Township, tanggaang Township and wanggetang Township in Xiahe County, and then joins Daxia river at the zero kilometer of Wanxia highway in wanggetang township. because

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