General situation of main stream of Red River

The Red River originates in wugang city, Henan Province, at the southern foot of Funiu Mountain, and flows through Wuyang County, Luohe City, Xiping County, Shangcai County and Pingyu County of Zhumadian City, and joins Ruhe River, the main tributary, in Bantai Village, Dungang Township, Xincai County. Below Bantai, it is divided into two tributaries, the Honghe River and the Honghe Diversion Channel, which flow through Huaibin County and Funan County of Anhui Province and join the Huaihe River at the Honghekou near Wangjiaba in Funan County at the junction of Henan and Anhui.

The main stream of the Red River is called Little Red River above Bantai and Big Red River below Bantai. The Xiaohonghe River and Ruhe River meet at the platform, and the drainage area above the platform is 1 1740 square kilometers, accounting for 95% of the total drainage area. Below Bantai, the Red River and the Red River are divided into two tributaries, leaving the province. The small red river has two tributaries in the upper reaches: Gunhe River and Danghe River;

Gunhe River, located in wugang city, is the source section of the Red River, which runs through central wugang city in southwest-northeast direction. Longwangchong, which originated in the southeast of Yangzhuang Township, flows northward through Baishiyagou to the foot of Gushan Mountain, and meets the lampstand and the single-headed cliff, which is called Sanchakou. Then it flows north to Dalishu, enters the warehouse at Yuanmen, slowly flows out of the mountain, flows northwest to paddy fields, enters the Shimantan reservoir area, enters the plain area to the north to Sushan, and winds northeast, becoming the boundary river of Wugong Township, Zaolin Township and Anzhai Township. Enter Xiping County at Xiaosishan, and join Tonghe at Heshui Village in Yangzhuang Township. The main river in wugang city is 45 kilometers long, generally about 100 meters wide, with a drainage area of 335.438+08 square kilometers and a drainage area of 329 square kilometers. The average annual discharge is 3. 13m3/s, and the safe flood discharge is about1000m3/s. The average gradient is 1/200.

Tonghe, which originates from Sitou Mountain in the southwest of Miaojie Township, wugang city, winds northeast through Miaojie Reservoir, crosses Batai in the north, enters Wuyang County in the northwest of Yan Zhang Cun, and then turns east to Zhuyaohuan Village in the north, which is called Li Sanhe. Sanlidian in Zaolin Township has become the boundary river between wugang city and Wuyang County. It flows eastward to Zhang Ying Village, enters Xiping County, and is called Xiaohonghe, also known as Caohe, and flows southeast to Heshui Village, Yangzhuang Township, where it joins the Gunhe River. The main river channel is 5 1 km long and 30-50 km wide, with a drainage area of 327.7 square kilometers. The average annual flow is 2.7 cubic meters per second, and the total annual runoff is 85.02 million cubic meters. Among them, the section of Temple Head-Naimuying is about 2 1km long, with a drainage area of 87 square kilometers, with an average annual runoff of 23.67 million cubic meters and an average annual flow of 0.75 cubic meters per second. The gradient is 1/200.

The two rivers flow eastward, meet in Heshui Village, Yangzhuang Township, Xiping County, and continue to flow eastward, injecting Jidu River in the middle, flowing through Xiping County, injecting silt river in Wugouying Town, and then turning southeast into Shangcai County.

In Shangcai County, the main stream is called Xiaohonghe, which flows through Xiping County, Bai Chi, North China, Xihong, Donghong, Taqiao, Mohu and Dangdian, and then flows into Pingyu County. The territory is 52.76 kilometers long, with an average mouth width of about 40 meters, and the interval drainage area is 465.5 square kilometers, accounting for 3 1% of the county's total area.

In Pingyu County, it entered the county from Yinqian Village, Liu Hou Township, and passed through 9 townships, namely Liu Hou, Wanjia, Sheqiao, Huang Yu Temple, Miaowan, Gao Yang Store, Donghuang Temple, Yangbu and Shuangmiao, and reached Xincai County. The territory is 53.7 kilometers long (197 1 50.2 kilometers after straightening Caiwan), with a drainage area of 939 square kilometers, accounting for 73% of the county's total area.

In Xincai County, the Little Red River enters from Liqiao Hui Town, passes through Shilipu Township and Xincai County, and joins Ruhe River in Bantai Village of Dungang Township, which is called the Great Red River (or Red River).

At this point, the small red river is 300 kilometers long and the basin area is 4350 square kilometers. (It is said that the river length is 25 1. 1km, and the drainage area is 1 1663km2) In Henan Province, the main stream of the Red River is divided into two tributaries after passing through Bantai in Xincai County: one is the main stream of the Red River, and the other is the flood diversion channel of the Red River. The two rivers flow in parallel and continue to the southeast direction.

The main stream of the Red River enters Funan County from Ji Fang Town, and enters the Huaihe River along the southern edge of zhang wan, Ji Fang, Zheng Wan, Hongheqiao, Hongji Town and Honghekou. Funan county is 45 kilometers long, with a drainage area of 4 1 1.3 square kilometers and an average riverbed width of 80 meters.

The flood diversion channel of the Red River starts from Bantai, Henan Province and goes up to the Red River. When the water level of the red river platform reaches 35.55 meters, flood diversion will be started to reduce the flood accumulation in the upper reaches of the red river and the load on the downstream dikes. The maximum flow rate is 750 cubic meters per second. It flows to the southeast, passes through Aiting in Linquan, enters from Deng Ying in Ji Fang District, and flows along the slopes near Yongdian, Ji Fang, Li Ji and Zhaicheng until Zhangjiagang meets the Huaihe River flood diversion channel. The whole journey is 80km, and Funan County is 4 1 km. There are intercepting ditches in tanggou, Yuncheng, Xiaopo, Hezhai, Loulou, Dicheng and along the lake on both sides, and there are drainage ditches at the mouth of Lingou. 1975 After the Bantai sluice was bombed, the flood diversion was out of control.

The total length of the Red River is 455 kilometers (3 12 kilometers), of which only 56 kilometers are in Anhui Province. The upper reaches are mountainous areas with fierce floods. The middle and lower reaches of the river are narrow and shallow, with low drainage capacity. The slopes on both sides are not well drained and often flooded.

The total length from Yangzhuang River in Wuyang County to Wugouying River in Xiping County is 36 kilometers, and the riverbed gradient is 1/5200. The reach from Wugouying to Hedaoqiao in Shangcai County is 48.9 kilometers long and the riverbed gradient is 1/6500. The length from riverway bridge to Miaowan River in Pingyu County is 3 1.5km, and the riverbed gradient is 1/8000. The total length from Miaowan to Wanding River in Xincai County is 55.4 kilometers, and the riverbed gradient is1/9000 ~110000. The length from Wan Ding to Bantai River is 1 1.8km, and the riverbed gradient is115000. The red river bed is narrow and deep, with a V-shaped cross section, and the upstream channel is only 50 to 60 meters wide. From Yangzhuang, there is a river bank with a distance of 100 ~ 750 meters.