Brief introduction and detailed information of Zijiang

Overview of the main stream: The river flows into Lengshuijiang City and Zijiang River, flows through Jin Zhushan, Heqing, Shatangwan, Maoyi, Panqiao, Lengban and Banbu, and leaves the country in the Guojia Community of Panqiao, with a total length of 23.65km, a natural drop of 7.25m, an average gradient of 0.4‰, a river width of 200-500m and an average annual discharge of 385m3/s.. The only navigable major river.

In Xinhua County, it enters the boundary of Xinhua County from Lengshuijiang City, also known as Cornus River, which is the mother river of Gumeishan culture. Zishui runs through the central part, dividing the county into northeast and southwest parts, and flows through 9 towns, including Shichongkou, Sang Zi, Shangmei, Youjia, Caojia, Youxi, Baixi, Langtang and Ronghua, with a total length of 9 1 km. The main tributaries of Zishui in China are Dayangjiang, Youxi, Zhuxi, Meixi and Qujiang. Rainwater catchment area is 3 1 12.5 square kilometers, with average water level 153.95 meters, maximum water level 175.44 meters and minimum water level 155.79 meters. 1959 The average flow rate is 377 m3/s, the maximum flow rate is 4090 m3/s, and the minimum flow rate is 40m3/s.196/year After the completion of Tuoxi Hydropower Station, the domestic water storage area reaches 149900 mu, accounting for 60.2% of the whole reservoir water storage area. Tian Zi, Wushishan, Xianheyan, Liu Shi, Ziyunyan, Guanyin Moon in Su Hu and other eight Zishuiyan scenic spots are picturesque, and the mountains and rivers are interdependent. Tianshui is the same color, with mountains, beautiful waters, springs and caves in the Baili reservoir area. It is a wonderful flower in the creation of nature in Hunan. Zijiang originated in Ziyuan County, Guangxi, with the same origin as Lishui, and is known as "Qing". Purple water enters from Xiaoxi, Xinshao County, from south to north, passes through Lengshuijiang City and Xinhua County, and enters Zhexi Reservoir for exit. There are abundant natural resources.

There are 170 streams in Anhua county with a main stream length of more than 5 kilometers. 196 1, Zhexi Power Station closed its water storage, forming a water surface of 85 square kilometers in Zhexi Reservoir.

There are two natural water sources: Zuoyuanshui comes from Beiqingshan in Chengbu Miao Autonomous County, and Fuyishui comes from Yuechengling in Ziyuan County, Guangxi. The two rivers meet at Shuangjiangkou, Shaoyang County, and flow through Shaoyang, Xinhua, Anhua, Taojiang and Yiyang, and then flow into Dongting Lake at Ganxi Port, Yiyang City, with a total length of 653 kilometers and a drainage area of 28 142 square kilometers. The total drop is 492m, and the river bend coefficient is 2. 16. Heyuan to Wugang City is the Heyuan section, Wugang City to Xinshao County Xiaomiaotou is the upstream section, Taojiang County Xiaomiaotou to Majitang is the middle section, and Majitang to Hekou is the downstream section.

Purple water originates from the border of Qingjieshan Huang Ma in the north of Chengbu County, flows into Wugang City through Niushiqiao in Chengbu County, flows through the middle of the border, and flows into Dongkou County in Tangtian Village of Maping Township. The domestic flow is 64.5 kilometers long, and the drainage area is 1087.97 square kilometers. There are six first-class tributaries in Zishui City: Yuxi, Longxi, Liaoshui, Longjiang, Tashui and Dejiang; Secondary tributaries 18: headwaters, Shipujiang, Qingxi, Xiaoshuijiang, Qushui, Baitang, Zhuxi, Ruoshui, Lianshui, Lengshui, Moxi, Zhu Jing, Huaqiao, Jinlong, Xiaojiashui, Shuangjiang, Tanghuang and Datang. There are 1 first-class tributaries in Fuyi Water, namely the Frozen River (also known as Dashui River and Yangmujiang River). There are three secondary tributaries: Shuangjiang, Qinqiao and Qianyuan River.

Purple water obliquely passes through Wugang from west to east, with a flow of 64.5 kilometers.

Zijiang River is divided into two sources above Shuangjiangkou (also known as Luojiamiao) in Xiatangyun Township, Shaoyang County: the western source is land water, which was also called Zishui and Douliangshui in the old annals, and it was called land water in Cihai 1979 edition. It originated at the west foot of Huangma Street, the main peak of Qingjie Mountain in Ziyuan Township, Chengbu Miao Autonomous County, and flowed through Wugang, Dongkou and Longhui from southwest to northeast. Among them, Heyuan to Guanchang Town, Wugang County is 49. 1 km, with high mountains and steep valleys and fast flowing water, with an average gradient of 6.85‰. Huangqiao town reach from Wugang County to Dongkou County is 53.5 kilometers long, with an average gradient of 0.89‰. Shaoyang county huangqiao town to Shuangjiangkou reach 86. 1 km long, with an average slope of 0.4 1‰. The river surface from Wugang to Shuangjiangkou gradually increases from 50m to about 150m, and the water flow along the way is gentle or shallow. The south source is Fuyishui (Fuyishui), also known as Luojiang, which originates from Jinzishan, Ziyuan County, Guangxi Zhuang Autonomous Region. It enters the market boundary at Tazizhai, Liu Ping Village, Shi Yao Town, Xinning County, passes through Langshan, Jinshi, Baisha, Huilongsi, Tangtiancheng and Tangdukou in Shaoyang County, and joins the land water at Shuangjiangkou. The domestic flow length is 155km, the drainage area is 3 150km2, and the average gradient of the national reach is 0.46‰. The width of the river from Xinning County to Shuangjiangkou is about150m. Zuishui and Fuyishui meet at Shuangjiangkou in Shaoyang County and are called Zijiang River, which flows northward through Jiugongqiao and Xinshao County in Shaoyang City and flows out of the urban area at Xiaoxi Village in Daishuiqiao Town. The reach from Shuangjiangkou to Xiaoxi is113.7km long, with an average gradient of 0.56‰, and the drainage area of the whole city is 4,754.6km2.. Because Shaoshui meets Xiaomiaotou in Xinshao County in the urban area, the flow is greatly increased, and the riverbed is 200-300 meters wide. Between the small temple head and the stream, there are steep mountains on both sides, and the water is rushing. The river is generally about 100 meters wide, and the narrowest part is only 30 meters. Zijiang River flows among the mountains. The east-west section of the main stream is narrow and the mountains are approaching. Affected by the local topography, most tributaries are short and the basin area is small. 96.3% of the tributaries are less than 50 kilometers long; 90. The tributary basin area of1%is less than 100 square kilometers.

There is a main stream and an east branch in Xiangyin County (formerly known as Zishui, 1952). Liu Yu flows from Yiyang City into Maojiaokou, Xiangyin County, along Nanhu Lake and the west of Dongting Lake, and flows into South Dongting Lake through Quanshui Village, Huangkoutan, Saitoukou, Yipotang and Yangliutan. East branch from Maojiaokou to the east, along the west of Xinquan District, flows into Xiangjiang River via Jiaotan Bay, Xilin Port, Nanhu Island, Guangongtan, Baima Temple, Hepingmen to Linzikou. Xiangyin section is 57.4 kilometers long, of which the main stream is 2 1.4 kilometers and the east branch is 36 kilometers.

Characteristics of the river channel Zuoyuan Lushui is the birthplace of deep mountains and steep valleys, with steep slopes and rapid flow, but it enters the intermountain basin near Wugang, with flat and open terrain and gentle slope; From Wugang to Shuangjiangkou, there are mostly low mountains on both sides, only local canyons, and most of the valleys are gentle; To Xiaomiaotou (located 34 kilometers downstream of Shaoyang City) is the upstream of Zishui. Xiaomiaotou to Majitang is a water tour. The river passes through Xuefeng Mountain, and the two banks face each other on the high mountain. The average elevation is about 1000m, the river valley is steep, the bedrock is * * *, the riverbed is densely covered with reefs, the flow pattern is disordered, the river channel is curved and narrow, and the maximum flow rate is 3.9m seconds. The valley is composed of hard rocks such as pre-Devonian metamorphic rocks and Devonian sandstone, which provides good conditions for the development of hydraulic resources. Below Majitang is the lower reaches of Zishui River, with a wide valley and flat terrain. There are many modern alluvial platforms and hills, and below Yiyang City is the Dongting Lake alluvial plain.

Fuyishui, a tributary of Heyuan, is the source of Jiangnan. Originated in the southeast slope of Laoshan Mountain in Ziyuan County, Guangxi Province (southeast of Maoershan Scenic Area in Guilin City, the highest peak of Yuechengling Mountain in 400 miles), Mu Tong, Sheling Village, Zhongfeng Township. The secondary source comes from the old source of Bafang Village. After the maple trees converge, they flow from south to north through Zhongfeng, Cave, Dahe and Meixi Township, and slip from Gedongping Village of Meixi Township into Xinning County, Hunan Province. Within the county, the flow length is 83. 1km, and the drainage area is 13 15.5km2 (including 70.03km2 of external water). The river is 248 kilometers long and the basin area is 4554 square kilometers.

Lushui, formerly known as Douliang Water, is the source of Jiangxi Province, with a river length of 188km and a drainage area of 7 149km2. It originated in Huangma Street, Gaokutang Village, maoping town (the original resource town), Chengbu Miao Autonomous County, Hunan Province, at the northern foot of Nanling Mountain. It flows into Zijiang River at Shuangjiangkou, Shaoyang County, Hunan Province.

Zijiang has 820 tributaries with a river length of more than 5 kilometers (including 770 in Hunan and 50 in Guangxi). According to the basin area, there are 39 first-class tributaries, with a river length of more than 100 square kilometers, among which the tributaries with a river length of more than 500 square kilometers are Liaoshui, Pingxi, Chenshui, Fuyishui, Shaoshui, Majiang, Dayangjiang, Youxi and Ququ in turn. Feather water system

Shaoshui, which originated in Nanchong at the northwest foot of Huilongfeng in Shuangfeng Township, Shaodong County, passes through Zhouguanqiao, Liangshitang, Niumashi and Yunshuipu Township and joins Zijiang River on the right bank of Jiangyan Bridge in Shaoyang City. The total length is 1 12km, the drainage area in China is 1965km2, and the average river gradient is 0.79‰. The larger tributaries are Tuojiang River, Xiyang River and Tanjiang River.

Chajiang River is a tributary of Lvshui River. Originated in Lijiaping, Shaoyang County, it flows into Shaoshui from the left bank of Xiaojiacun via Cunninghamia lanceolata Bridge, Huangjiaba Reservoir and Xianchaqiao Town in Shaodong County.

The western river belongs to a tributary of land and water. It originates from Yuepingfeng in Xinshao County, passes through Taiji Temple, Tanfu, Chenxiang and Fanjiashan Town in Shaodong County, and flows into Shaoshui from the right bank of Niumashi.

Tanjiang River is a tributary of Lvshui River. Originated at the southern foot of Jianmuling in Dong 'an County, it entered the city at jiepai Bridge in Wufengpu Town, Shaoyang County, passed Wufengpu, Zhonghe, Xiahuaqiao, Guzhou Township and Tanjiang Township in Shaoyang Suburb, and flowed into Shaoshui from the left bank of Shuangjiangkou.

Pingxi River is a tributary of Lvshui River. Originated in Longxi 'ao, Xima Township, Qianyang County, Hunan Province. It flows through Dongkou County and flows into good water at Longtanpu. The total length of the main stream is 100 km, the drainage area is 2,300 square kilometers, and the average annual flow of the estuary is 76 cubic meters per second. The upstream flows through Xuefeng Valley, winding and rushing, and the middle and lower reaches are hilly areas with gentle flow velocity. The main tributaries are Changtang River, Gulou River, Banjiang River and Huangni River. It is possible to sail under the Shijiang River. Pingxi River, known as Xiakou water in ancient times, is also called Dongkou water. Originated in Dawan, Qianyang County, it entered the Jiangkou, Dongkou County, passed through Yuexi, Dongkou Town, Dongkou County and Zhu Shi, and then merged into the water from the left bank in Longtanpu, Shijiang Town. The total length of the main stream is 93 kilometers, the drop is 26 1 m, the riverbed is 70.8 meters wide, the annual average flow of the estuary is 76 cubic meters per second, and the basin area is 2269 square kilometers.

Huangni River, a tributary of Pingxi River, was called Wangni River in ancient times, also known as Shanmen Water. Running through the northeast of our county. The Huangnihe River originates from baimashan, Longhui County, flows through Tongshan Township, Shanmen Town and Shuidong Township in Dongkou County, and flows into Pingxi from the left bank at Chuanshishan. The total length of the main stream is 4 1km, and the drainage area is 436 square kilometers.

Liaoshui River is a tributary of Lvshui River. As an important tributary of Zijiang River, one of the four major rivers in Hunan Province, it is also known as Wuyang Water, Zhuzhu Water (called Zhu Zhu County in Suining in ancient times) and Gaosha Water. Originating from Qipo Mountain in Suining County, it flows through Wuyang, Li Xi Bridge, Hongyan, Dongkou County Park, Xi Zhong and gaosha town, and joins Zhushui (left bank) at Shuangjiangkou, Ma 'an, gaosha town. The total length is 97 kilometers, the drainage area is 1 14 1 km2, and the average river gradient is 2.32‰. In Suining, from the source of Wuyang to the mouth of Hongyan Gorge, the main tributaries are Shuanglong River, White, Tangjiafang River and Huangtu Mine River. Suining Basin governs seven towns, including Wuyang, Tangjiafang, Wawu, Li Xi, White, Huangtu Mine and Hongyan, with an area of about 800 square kilometers, less than one third of the total area of Suining, but its population accounts for 60% of Suining. The main stream of Liaoshui is parallel to the provincial highway S32 1 and tied with Wuyang, Li Xi and hongyan town. It is the most populous and economically developed area in Suining.

Shi Ma Jiang, originating from Shouwang Pavilion in Longhui County, flows into Zijiang from the left bank of Dayu Temple through Gaoping, Wuxing and Liyan Township in Xinshao County. The total length is 76 kilometers, the drainage area is 840 square kilometers, and the average river slope is 2.04‰.

Chenshui River originates from Pinggang at the northern foot of Wangyunshan Mountain in the north of Longhui County, flows through Dashuidong, Yanggu 'ao, Liuduzhai, Hexiang Bridge and Shimen, and joins Zijiang River in Taohong Town. Longhui County has a total length of 88 kilometers and a drainage area of 844 square kilometers. It is the second largest river in Longhui County.

Dayangjiang, the largest tributary of purple water, enters from Jin Shiqiao, Longhui County, flows through Shuiche, Datong and Yunxi Township from west to north, and then turns east, passing through Furnace View, Qingshan, Shixin, Beidu Township and Youjia Town, and injects purple water into Dayangjiang Village. The total length is 9 1 km. Watershed area 1285 km2. The process in this area is 83 kilometers. Along the way, it includes Zhongzhou River, Xishi, Yangxi, Ruxi and other major tributaries. Rich in water resources, the river valley is steep all the year round, with an average flow of 40. 18m3/s for many years. It is the main water source for industrial and agricultural production in towns and villages such as Furnace View, Youjia, Xihe, Yangxi and Liaoyuan, and also the key river for hydropower resources development in Xinhua County. Three hydropower stations, Datong, Shuangjiangkou and Luguan, have been built, with installed capacity of 13570kW.

Dayang River: Dayang River is a first-class tributary of Zishui, which originated from Hongyan Mountain in Longhui. After the Dayang River in Xinhua County joins the Sanjiangkou in Beidu Township, it belongs to the general name of Shihexi River, Yangxi River and Ruxi River in this county. The length of water put into Sanjiangkou is about 10.5km, the river surface is about 80-250m, and the total area of rainwater collection in the county is 1098.7km2.

Youxi, a first-class tributary of Zishui, is the intersection of the downstream of Youxi and Zishui. Originated in Gaitou Mountain, Gutang Township, Lianyuan City, the water enters Chetianjiang Reservoir, flows through Chetianjiang, Tian Ping, Wentang, Chaxi, Zuoshi, Chenguang, Qing Ji, Chongshan and Banshan Township in our county from west to north, turns southwest, crosses Dongfu Township and flows into Youxi Township, with a total length of 67 kilometers and a drainage area of 7 19 square kilometers. The average flow for many years is 16.84 m3/s, and the water flow is turbulent. It is the main water source for agricultural production and the main river for hydropower development east of Zishui in Xinhua County. After many surveys and planning by provincial, prefectural and county water conservancy departments, the installed capacity is more than 22,000 kilowatts, and two power stations, Tieshanba and Jianjun, have been built one after another, with an installed capacity of 2,250 kilowatts.

Youxi, the second largest tributary of Zijiang River in Xinhua County, is named after the clear water. Located on the east bank of the Zijiang River in the north of Xinhua County, it originated in Jiaolaoling, Lianyuan City and flows into the Zijiang River in Youxi Village, Youxi Township, with a total length of 67 kilometers, a rainfall collection area of 7 19 square kilometers, a gradient of 4.2‰, a drop of 28 1 m, and an annual average flow of 65,438. Because of the abundant water and large drop, Chetianjiang Reservoir and its supporting projects were built in its upstream, which solved the irrigation problems of farmland water conservancy in six towns in Hedong, Xinhua County. Five cascade power stations will be built in the middle reaches.

Baixi, located in Baixi Township, Xinhua County, originated in Taozidang, Anhua County. Baixi, like a 43-kilometer-long jade belt, is one of the four major rivers in Xinhua County, surrounding the mountains in the north of Xinhua County and injecting water from the west side of Baixi Town.

Qiuxi River, a first-class tributary of Zishui, originates from Heshuchong in Xinshao County, flows through Tian Xin, Cao Shi, Sanjian and Heqing in Lengshuijiang City, and joins Zijiang River between Yangping and Qiuxi, with a total length of 28km and a drainage area of104km2, of which16.15km is within the territory, and 58.59 is within the territory. The average annual flow is 27,600 cubic meters per second and the average annual water production is 87.04 million cubic meters. More than 2000 hectares of farmland are irrigated by water from cascade dams along the river.

Maxi River, a first-class tributary of Zishui, originates from Pingzhen, Xinshao County, flows through Hengxing, Yangyuan, Maxi and Zijiang Village, Jinzhushan Town, Lengshuijiang City, and joins Zijiang River at Maxikou, Zijiang Village, with a total length of 3 1km and a drainage area of 128 km2. Among them, the territory is 3.79 kilometers, the drainage area is 17 square kilometers, the average gradient is 1.7‰, and the annual export flow is 3.84 cubic meters per second.

Liuxi River originates from Dishui Village, Zi Long Township, flows through Zi Long, Maoyi and Shaban in Lengshuijiang City, and flows into Zijiang River at Liuxikou. It has a total length of 2 1.5km, a drainage area of 52.9km2, an average gradient of 16.6‰, and an average annual discharge at its outlet of1.55m3/s.

Qujiang is a first-class tributary of Zijiang River in Hunan Province. Qujiang originates from the remnants of Xuefeng Mountain, and its sources are Fuxi Village in Anhua County and Yangjiaoshan Village in Xupu County. It flows into Anhua County through Yan Jia Village of Qujiang Town. It flows through Yan Jia, Chengping, Shengjia, Cunpihua, Datang, Li Antang, Tao Ping, Lilian, Lighthouse, Daan, Qujiang 13 villages in Qujiang Town, Anhua County, and flows into Zijiang Village in Xupu County, with a total length of about 230 kilometers. The population of the basin is about 500,000, and the irrigated paddy field area along the river is 200,000 mu. Qujiang starts from Xinhua, passes through Xupu and Anhua, and flows into Zijiang. The source of Qujiang River is located in Feng Jia Town, Xinhua County, including Feng Jia, Shuiche, Tianmen, Jinfeng and Gutai Mountain. It is the origin of Qujiang tablets, Fengjiamicha and other tribute teas and China famous tea "Crescent Tea".

Jishui River, originating from Jishui Village, Le 'an Town, flows through towns such as Le 'an, Meicheng, Xianxi, Changtang, Taoxi and Xiaoyan, with a total length of 83.8 kilometers and a drainage area of 1 120 square kilometers. It is a first-class tributary of Zijiang River.

Yixi, the first tributary of Zishui River system, originated from Guiyan Mountain, Dongshan Township, Anhua County, with a total length of 79.3 kilometers. From south to north, it flows through Anhua County and Taojiang County and flows into Zijiang River at Majitang.

Xi Zhi is a first-class tributary of the Zijiang River, with a total length of 68.5 kilometers and a drainage area of 680.5 square kilometers (including 2 square kilometers in Ningxiang County, 225. Taojiang County is 3 square kilometers, and Heshan District is 453.2 square kilometers). It enters Zijiang through township offices such as Nijiangkou, Longguangqiao, Xinshidu, Xielingang and Huilongshan in Heshan District.

Watershed environment Zijiang, also known as Zishui, is located in the middle of Hunan Province, bordering Xuefeng Mountain and Yuanshui River in the southwest, Hengshan Mountain in the east, Xiangshui River in the south and Guishui River Basin in Zishui, Guangxi in the south. The basin shape is long from north to south and narrow from east to west; The terrain is high in the southwest and low in the northeast. The hills and basins in the basin account for about 40%, most of which are distributed in the upper and lower reaches, and the hills account for about 50%, mainly distributed in the middle reaches, and the rest are plain lakes.

Zi Shui Gu is located in the subtropical monsoon region, with an average temperature of about 20℃, distinct seasons and mild climate. The annual rainfall is generally between 1200~ 1800 mm, which is a humid area. Rainfall is mainly concentrated from April to August. The average annual flow is 760 cubic meters per second, and the annual runoff is 24 billion cubic meters. The basin is rich in hydropower resources, with a hydropower reserve of 2.24 million kilowatts (20 1 10,000 kilowatts in Hunan) and an exploitable amount of about14800 kilowatts. Due to different natural conditions, the development focus of Zishui reach is different: the middle reaches are mainly for power generation and flood control, and Zhexi Reservoir is located in this section; Upstream is mainly irrigation and power generation; The downstream can be developed with low head for shipping and power generation. The topographic conditions in the basin are complex, and the spatial and temporal distribution of rainfall is extremely uneven due to the influence of atmospheric circulation. Anhua to Taojiang is the largest rainstorm area in the province, while Shaoyang is a famous arid hilly area, with long-term drought and no rain in the high temperature season in summer.

Hydrological characteristics Zishui River Basin is characterized by low mountains in the south, hills in the east, rolling hills in the middle and plains in the northeast. The southwest is high and the northeast is low. Mountains account for 55%, hills account for 35% and plains account for 10%. The average annual precipitation in Zishui Basin is1483.3mm. The high-value areas are from Dongkou to Longhui and Anhua to Taojiang in the west of the basin. The area from Xinning to Shaoyang in the southeast is a low-value area. The extreme maximum value is 2605.3mm (Robbie Station in Taojiang County 1969). The extreme minimum value is 7 18.8mm (Zhujiating Station, Shaoyang County, 1960). The distribution of precipitation in a year is uneven. The maximum monthly precipitation generally occurs in May or June, and the minimum monthly precipitation generally occurs in 65438+February or 65438+1October. The precipitation in flood season (April-September) accounts for 67.3% of the whole year. The average evaporation of water surface for many years is about 700 mm, and there are frequent rainstorms in Zishui basin during flood season, mainly from Anhua to Taojiang, Ziyuan and the north of Longhui. The number of heavy rains is the most in May-June, but the extreme value mostly appears in July-August. 1991August 26 -27, the 24-hour maximum length of Menggongtang Station in Taojiang is 47 1.5mm ... which is the largest rainstorm actually measured in Hunan Province. Heavy rain causes floods, and the maximum peak discharge mostly occurs in June, July and August. The measured maximum flood peak discharge at Taojiang Station15300m3 per second (1955, August 27th). The average annual runoff in Zishui River Basin is 25.2 billion cubic meters, and the annual distribution corresponds to the seasonal variation of rainfall. The annual average maximum runoff for four consecutive months generally occurs from April to July, accounting for 54% of the total annual runoff. The annual runoff changes greatly, with the maximum annual runoff of 37.48 billion cubic meters (1994) and the minimum annual runoff of14 billion cubic meters (1963).

Natural disasters Natural disasters often occur in water resources basins. Hilly areas are prone to drought, and there is a drought of flower arrangement every year, which lasts for about 6 years.

According to historical records, in the year of 1900, Wugang began to work continuously in mid-April 100, and the pond opened, the seedlings withered, and 86 people starved to death in Zhu Jing township. 1 17 families fled. 192 1 There have been continuous droughts in spring and summer, especially in Baoqing and Wugang, where Dingkou has been greatly reduced. 1925 Baoqing, Wugang, Xinning, Chengbu and other places have a drought period of more than 80 days from May to July. 1963 The total disaster area of the main counties in Zishui River Basin is about 2.5 million mu, and the disaster area is1300,000 mu, and the grain output is reduced by about 500 million Jin. It is difficult for people to store drinking water in some dry dead corners. Local floods and flower arranging floods in hilly areas have occurred almost every year in history. Great floods occur every three to five years. According to the chronology of natural disasters in Hunan Province: 1482 to 1949, a total of 129 times occurred, and the flood year was 18 years. 16 17 was a very serious flood year, which was recorded from Wugang to Yiyang. For example, "Shaoyang County Records" contains: "Ding drifted away from Qinglong Bridge in the flood and entered the city from battlements to destroy houses." "Xinhua County Records" contains: "In May, floods entered the city, with no east, west and north gates". The flood discharges of Shaoyang and Xinhua are 13600 m3/s and 14600 m3/s respectively. 1924 "Jiazi Dashui" is the second largest flood year in the upper reaches of Zishui River. From 1950 to 2000, there were seven years of basin floods, of which 1996 was the most important, and the upper reaches of Zishui River were second only to 16 17 and 1924. The measured peak flow at Lengshuijiang Station reaches 1 1000 cubic meters per second. The measured peak flow at Taojiang Station is 1 1600 cubic meters per second. The flooded area of Shaoyang city is half, the main street is more than 2 meters deep, and Taojiang county is flooded for 8 days and nights.

Harnessing and developing Chetianjiang Reservoir: Chetianjiang Reservoir is located in the upper reaches of Youxi River, a first-class tributary of Zishui, in Wentang Town, Xinhua County. The rainwater harvesting area is controlled at 85km2, the total storage capacity is 65438+275 m3, the dam crest elevation is 496.75m, and the maximum dam height is 68.85m The water source conditions in Chetianjiang reservoir area are good and the water quality is excellent. The main utilization functions of reservoirs are irrigation and water supply.

Liaoshui Irrigation District is located in the south of our county, west to the eastern foot of Xuefeng Mountain, north to Pingxi River, south to Liaoshui River and east to the intersection of Liaoshui River and Pingxi River. It is a long and narrow triangle, irrigating eight towns and a state-owned farm in Dongkou County, with a designed irrigation area of 186970 mu. The total length of the main stream is 92km, and the drainage area is 1 14 1 km2.

1995 the planning report of zishui river basin and the review results of hydraulic resources are drawn up. the main objectives of zishui river development above zhexi river are comprehensive utilization of irrigation, power generation, flood control and shipping. The main objectives of the development below Zhexi River are flood control, power generation, shipping, irrigation and other comprehensive utilization of shallow hills and arid areas on both sides of Zishui River. There are 22 planned cascade developments in the main stream of Zishui River, of which 13 is below Shuangjiang Estuary, namely Peacock Beach (222.0m, the elevation of the Yellow Sea, the same below), Shentan Ferry (265438+55.7m), Sungu Beach (208.0m), Xiaoxi (198.0m) respectively. Xiushan (42.7m) and Shijiazhou (34.0m), when planning, Zhexi and Majitang were hydropower stations. After several years of construction, except for Shentandu, Jintangchong, Shijiazhou and Peacock Beach, all the other steps have been completed and put into operation. Fuyishui, a tributary, is planned to have 65,438+00 cascade development. Quanmutang is planned to be a large reservoir, involving Hunan and Guangxi provinces (regions), mainly to solve the drought problem in hilly areas of Shao Heng, Hunan Province, and improve the downstream flood control standards. Pingxi, a tributary, is planned to be a five-level development, and two tributaries have been built by the beginning of 2 1 century.

Dongkoutang is planned as a large reservoir, and its development goal is mainly to generate electricity, taking into account the comprehensive benefits such as irrigation and water supply.

Xiaoxi hydropower station Xiaoxi Hydropower Station is located in Xiaoxi Village, Pingzhen Town, Xinshao County, Shaoyang City, Hunan Province. Construction started in 2004 and was completed and put into operation in 2008. Its dam line is located at the exit section of Longkouxi Canyon, 0.7 km upstream of the entrance of Xiaoxi River. Under the dam site, it is 6 km away from Lengshuijiang City1,45km away from Xinhua County, 44km away from Xinshao County and 58km away from Shaoyang City. The dam site of this project controls the drainage area of 15843 km2, accounting for 56.5% of the total drainage area, and the average flow of the dam site for many years is 409m3/s. This project is the fourth stage of the upstream of Zhexi River, the main stream of Chinese water in Zishui River Basin Planning Report (1995), and the lower part is connected with the tail water of Langshitan Power Station Reservoir and the upper part with the tail water of Shaigutan Power Station. It is a hydropower project with comprehensive utilization of power generation and shipping. The normal water level of the hydropower station is1.98m, the installed capacity is1.35kW, and the annual power generation is 504 million kWh. It was completed and put into operation in 2008. The operation mode is as follows: when the normal water level of Xiaoxi Reservoir is 198m, the corresponding storage capacity is 98.6m 3, the dead water level is 196m 3, and the corresponding storage capacity is 83.26m 3, and the storage capacity is adjusted15.34m3; With daily adjustment performance; The project mainly focuses on power generation, with comprehensive utilization such as shipping; The maximum head is 22.2m, the minimum head 10m, the weighted average head is 20.7m, and the rated head 19m. The power station in the power grid can be located at the waist peak load position in dry season or dry day; In flood season, the power station can operate at the waist-base load position depending on the incoming water situation and the needs of the power grid; When the inflow is less than 89.8 m3/s, the storage capacity is adjusted and the small unit generates electricity. The water level of the reservoir is maintained between the dead water level 196 m and the normal water level 198 m, the gate is closed, and the water is discharged through the small turbine to maintain the downstream shipping and ecological needs. When the inflow is greater than 89.8 m3/s and less than or equal to the unit excess flow of 8 12.6 m3/s, the water level of the reservoir is maintained at the normal level 198m, the gate is closed, and the inflow is discharged through the hydraulic turbine; When the water inflow is greater than 8 12.6 m3/s, the water inflow is greater than 812.6m3/s.

Langshitan hydropower station. Langshitan Hydropower Station is located in Dawanli, the main urban area of Lengshuijiang City, Loudi City in the middle reaches of Zishui River. It was completed and put into operation in 2008. It is 18.02km away from Xiaoxi hydropower station dam site and 160km away from Zhexi hydropower station. The dam site of this project controls the drainage area of 16250km2, accounting for 58% of the total drainage area, and the average flow of the dam site for many years is 409m3/s. The lower part of this project is connected to the reservoir tail of Zhexi Hydropower Station, and the upper part is connected to the tail water of Xiaoxi Hydropower Station. It is a third-class medium-sized water conservancy project focusing on power generation, taking into account the comprehensive benefits of shipping and beautifying the city. The normal water level of this project is1.75m, and the corresponding storage capacity is 22.6m3.. The daily regulating capacity of the reservoir is 4.44m m3, the installed capacity of the power station is 3 units /36MW, the guaranteed output is 5.5MW, and the average power generation for many years is1.46 MW h. The basic principle of reservoir operation is to properly handle the relationship between power generation and comprehensive utilization of shipping under the premise of ensuring the safety of hydropower dams, and make full use of hydraulic resources to maximize the benefits of the whole project. The shipping base load flow of this power station is equal to the guaranteed flow of 96m3/s. In dry season or dry season, when the flow is less than or equal to 96m3/s, it will not undertake the peak shaving task. When the flow rate is greater than 96m3/s, the difference between the flow rate and the shipping base load can be located at the waist peak load position, and it can be operated at the waist base load position in flood season. When the inflow is less than or equal to the unit's excess flow of 73 1.7m3/s, the reservoir water level is maintained at the normal level 175.0m, and the gate is closed; When the inflow is greater than 73 1.7m3/s, the reservoir water level will be maintained at 175.0m when the inflow is greater than 73 1.7m3/s and the frequency is P=50%.

Zhexi Hydropower Station Zhexi Hydropower Station is located in Tang Rong Grand Canyon of Zishui River, Anhua County, Yiyang City. It is 0/60km away from Langshitan Hydropower Station/kloc-0, and the control basin area above the dam site is 22,640km2, accounting for 80.7% of Zishui River basin area. The project started on 1958, and the first unit was put into production on 1962. Zhexi hydropower station mainly generates electricity, and has comprehensive benefits such as flood control, shipping and irrigation. The normal water level of the reservoir 167.3m, the flood control limited water level 160.3 ~ 163.3m, the flood control high water level 168.3m, the dead water level 150.3m, the total storage capacity of the reservoir is 3.57 billion m3, and the flood control storage capacity is 7. The original designed installed capacity of the power station is 447.5MW, the guaranteed output is 127.2MW, the annual average power generation is 265,438+46 million KW·h, the installed utilization hours are 4,800 h, and the water utilization rate is 80%. Through the measures of controlling water level by stages and grading and flood forecasting and dispatching, the downstream flood control standard has been raised from once every six years to once every 20 years, and the effect of reservoir flood regulation and peak shaving is obvious.