Yihe River

Yihe River

Yihe River is one of the tributaries of Luohe River, a tributary of the South Bank of the Yellow River in China. It originates from taowan Town, Luanchuan County, at the south foot of Xionger mountain. It flows through Song County and Yichuan County. It meanders at the south foot of Xionger mountain and the north foot of Funiu Mountain. It passes through yique and enters Luoyang. It flows into Luohe River from the northeast to Yanshi and merges with Luoshui to form Yiluo River. It has a total length of 264.88 km and a drainage area of more than 6100 square kilometers. Yihe River and Luohe River hold up a heavy wing of Heluo culture. "Yiluo civilization" is praised as "Oriental two river civilization" by some Western historians. Longmen Grottoes, China's famous world cultural heritage, are on both sides of the Yi River.

General situation of main stream

Trend of main stream

Yihe River, named luanshui in ancient times, originated from Mudun ridge, Sanhe Village, taowan town. According to the book of mountains and seas, "the mountain of manqu and Yi River come out.". "Huainanzi" contains: "Yishui out of Mount Wei.". Manqu mountain or Shangwei mountain is the ancient name of Mudun mountain. "Out of Xiong'er mountain" on the geography record day. After the 1950s, geologists have made many explorations and found that the mountain structure and geological characteristics of the Mt. Mudun range belong to the Funiu Mountain system, so the so-called "chuxiong'er mountain" is wrong. The Yihe River flows from west to east between the northern foot of Funiu Mountain and the southern foot of Xionger mountain. From the source to Tangying village of Tantou Township, the river flows into Songxian County, through Yichuan, Longmen and Yanshi, and then flows into Luohe River in Yangcun village of Guxian town. The total length of the river is 264.88 km, with a total drainage area of more than 6100 square kilometers.

In Luanchuan County, it starts from the birthplace of mudnling, Sanhe Village, taowan Township, passes through taowan Township, Shimiao Township, Luanchuan Township, Chengguan Town, Miaozi Township and Daqinggou Township, and ends at the exit of Yihe River, Tangying village, Tantou township. It covers an area of more than 1053 square kilometers, with a riverbed width of about 100 meters and a water surface width of 10-20 meters, with an average annual runoff of 368 million cubic meters.

In Songxian County, from Tangying village, Tantou Town, Luanchuan County, along the southwest to northwest between Waifangshan and XIONGERSHAN, there are 69 villages in Jiuxian, Dazhang, Deting, Hecun, Zhifang, Chengguan, reservoir area, fanpo and Tianhu, which flow through Songxian County. They leave Qianqiu village, Tianhu town (150 meters above sea level). Yihe River comes out of Songxian County and lives in Yichuan. Songxian section has a total river bed length of 80 km, a drainage area of 1731 square km, an average river bed width of 1500 m, with water throughout the year. The average flow is 10 cubic meters per second, the minimum flow in dry season is 1.1 cubic meters per second (April 1978), and the maximum flow in rainy season is 4800 cubic meters per second (July 1982).

In Yichuan County, from Tianhu town of Song County into the county, it flows through 8 townships (towns) and 66 administrative villages, including Jiuhou, Minggao, gezhai, Baiyuan, Pingping, Chengguan, Shuizhai, Pengpo, etc., to Guozhai village of Chengguan town into Longmen in the suburb of Luoyang. The main stream is 41.3 kilometers, and the drainage area is 943.4 square kilometers.

In Luolong District (former suburb) of Luoyang City, from Weiwan village of Longmen town to xishiba village of Lilou Township, it is 17 kilometers long with a drainage area of 68 square kilometers. The channel flows to the northeast, and the riverbed is of sandy pebble structure. The annual average runoff is 1.49 billion cubic meters and the runoff depth is 224.4 mm. In 1993, a rubber dam with a length of 302 meters was set up 250 meters downstream of Longmen Bridge, forming a water surface of 44 hectares and storing 890000 cubic meters of water.

In Yanshi County, the Yihe River flows from west to East, the north bank flows through houshiba, Huangzhuang, Wangzhuang, xianggongzhuang, Xitian village, Dongtian village, ningzhuang, Qianwang, Wangqi, Zhenzhuang, Tongzhuang, Zhaozhuang street, Dongzhuang and Yuetan; the south bank flows through Xima village, Xiji, Kangzhuang, Baita, Heilongmiao, Yangwan, Xinmin, Yuancun, dongshiba, Caodian, Diandian, xipengdian, Gaoya, Zhaozhai and bange Zhai, wangchagou, DUANWAN, Miaowan, Renzhuang, Guxian, ananian, Zaozhuang, Yangcun. The length from Xima village to cunyang Heluo river mouth in Yanshi section is 37 km, accounting for 10.7% of the total length of Yi River 347 km. The drainage area is 565 square kilometers, accounting for 59.9% of the total area of the county. The widest part of the riverbed (dongshiba) is 3.2 km, and the narrowest part (Antan) is 0.38 km. The longitudinal slope changes from one hundredth of longmenkou to about 1 / 3000. The river bed is composed of pebbles and sediment with good water permeability. Due to the small drop, the sediment deposition is the largest, and there are many sandbars in the river, which cannot be navigable.

Channel characteristics

From the source to the bottom of the temple, there are many bends and large drop. From miaodi to Miaozi, it flows from west to East, forming a 40 kilometer long wide valley. From miaodi to the two estuaries of Miaozi, there is a right angle turning. From south to north, it flows to Tantou ancient city, forming a 50 kilometer long valley. The slopes on both sides are steep, the river channel is narrow, moving back and forth is tortuous, the water potential is turbulent, and there are multiple water drops. After passing the ancient city, it turned right angle from west to East, and the water potential was gentle, forming the Tantou wide valley basin.

The upper part of Yihe River is from its source to Yakou (Songxian County). The length of the river is 154 km, of which the canyon section is 100 km. It is characterized by alternation of Canyon and basin. It originates from the deep mountain area. From the bottom of the temple to Miaozi, it is a wide valley and riverine plain with a length of 40 km. The river from Miaozi to Gucheng passes through Archean crystalline rock series. A 50 km long Daqinggou gorge is formed. The average depth of this section is about 250 meters. The valley slope is steep, the river channel is narrow, the water surface is usually 20-40 meters wide, the flow is very fast, and there are multi-level water drops. After passing through the ancient city, Yihe River successively passes through three basins (Tantou Zhongying Guxian). They are separated by three canyons, forming a beaded state of one bunch and one release, alternating wide and narrow canyons. Among them, the section from songdougou to Yakou is the longest, reaching 27.5km. Although the gradient of the upper section is not large, with an average of 5, the flow path is tortuous. The bending degree is 2.27. The lower part of the river is 114 km long below the Yakou. Although there are two canyons in the lower part, they are both short and small. Luhun gorge is only 0.1 km long, which is formed by the channel cutting through igneous rocks. Longmen gorge is 1.5km long and cut through limestone. Most of the rest reaches have wide valleys, shallow hills and flat terrain. In Yichuan, the average Valley width is 3-6km. In Longmen gorge, the Yi River is more open on both sides and the river is wider. Generally, the water surface is 60-150 meters. The lower part of the river bed drop decreases, which is only 1 / 3 of the upper part of the gradient. Therefore, the more downstream the sediment deposition is, the more serious the sediment deposition is. Moreover, the river channel flows straight to the northeast, and the curvature is only 1.21.

hydrographic features

In Luanchuan County, the runoff of Yihe River is affected by precipitation, topography, vegetation and production activities, especially by precipitation. From June to August every year, the average annual precipitation in Luanchuan is 421 mm, accounting for more than 50% of the annual precipitation, which is the flood season. When the daily precipitation is more than or equal to 50 mm, it becomes a rainstorm, and the river increases sharply, causing flash floods. Floods in the upper reaches of the Yihe River occur at least twice or several times a year. The largest peak discharge was 1370 m3 / s in August 1954, the highest in the history of the Yi River. Even in August 1975, which is known as the "758 floods", there has been heavy rain for seven and a half days since the 5th. The peak discharge of the Yihe River is 503m3 / s, which is far lower than that of 1953 and 1954. Generally, it is about 200 m3 / s. The minimum discharge year was 23.4 m3 / s in 1976.

The mainstream and tributaries of the Yihe River carry sediment into the river from precipitation, runoff generation, confluence and runoff formation. In 1981, the highest sediment concentration was 210 kg / m3, and in 1984, the youngest was 31.6 kg / m3. It is about 100 kg in general. The year with the largest sediment discharge was 1996, with an annual sediment discharge of 5.49 billion tons. The youngest year was 1976, with an annual sediment discharge of 240 million tons. In general, the annual sediment discharge was between 1-3 billion tons. The maximum year of sediment transport rate is 1966, the flood sediment transport rate is 17.4 kg / s, the minimum year is 1976, it is 0.678 kg / s, the general year is about 10 kg / s.

According to the relevant data of Longmen and Luhun hydrological stations, from the beginning of the 20th century to 1988, the Yihe River experienced relatively large flood discharge six times: 10300 m3 / s in 1931, 7180 m3 / s in 1937, 6480 m3 / s in 1943, 5740 m3 / s in 1954, 6850 m3 / s in 1958 and 6648 m3 / s in 1982. The minimum flow rate is 2.5 m3 / s.

In Yanshi County, since 1952 (according to the data of Longmen hydrological observation station), the maximum flow of Yihe River is 650 m3 / s, corresponding to the altitude (July 17, 1958); the minimum flow is 0.43 m3 / s, corresponding to the altitude of 148.65 m (June 26, 1955); the maximum flow is 154.5 m, corresponding to the flow of 5550 m3 / S (July 30, 1983), the minimum flow is 148 m, corresponding to the flow of 0.68 M The average annual sediment concentration is 2.93 kg / m3, and the average annual runoff from 1965 to 1978 is 722 million m3.

In normal years, the Yihe River freezes in December and January of the next year, and the ice layer is about 2 cm thick.

Main tributaries

Luanchuan county section

The main tributaries of Luanchuan county are as follows:

Xiaohe, the ancient name of Yongshui, originated from Baitu township

Chinese PinYin : Yi He