Xiaoxi, from Shawan, Jingning County to Xikou, Xishi Township, qingtian county, has a navigable mileage of 14 1 km. The main ports along the line are Biaoxi, Wu Tong, Xinting, Waishe, Admiralty, Bohai, Chencun, Baiyan and Rengong. The reach runs through the valley, pebbles in the river bed and rapids, among which there are 36 large and small beaches 136, 69 main rapids, with an average gradient of 0. 15%, a beach surface gradient of 0.3% ~ 0.467%, a river width of 80 ~ 200m, the lowest navigable water level of 0.4m, and the shallowest depth in dry season of only 0.4m.. The suspension period is from June each year 1 1 to June next year 1. Shawan to Waishe can connect 1.5 ~ 2.5 tons of wooden sailboats, and Waishe to Shixikou can connect 2 ~ 2.5 tons of motorized wooden boats. Navigation is prohibited after Songyin River, Xuanping River and Haoxi River 1985.
The main stream valley of Oujiang River is deeply cut, and the peaks on both sides are steep. Wenxi Street is a mountain stream with lithologic banks and pebble beds. The river is wide and narrow, with deep pools and shoals alternating. Almost the whole river runs through the valley. Along the river, except for some terraces where Aoshan meets tributaries, there are only small plains from Dagang Tou to the middle reaches of Lishui and alluvial plains below Mei Ao. With the completion of Jinshuitan and Shitang power stations, Shitang to Longquan have become the backwater areas of two reservoirs. The Longquan-Lishui section of the Longquan-Lishui navigation section is 1 17km long, passing through Dabaiban, Daotai, Anrenkou, Wuxi, Chishi, Longmen, Shipu, Jucun, Shitang, Dagangtou, Bihu, Shi Niu and Subu. The elevation difference of the whole section is 130m, the average gradient is 0. 134%, and there are more than 20 beach hazards 120, of which 65 are seriously obstructed. Generally, a 2.75-ton stern boat is navigable, and it can go up in 7-8 days and go down in 2-3 days under normal water level. During the flood, the current was swift and the water potential was turbulent, so the ship stopped sailing for a period of time to avoid the flood. In the dry season, due to the lack of water depth, the 2.75-ton stern boat only carries 600 ~ 1000 kg upward and 1000 ~ 1500 kg downward. When the boat reached the shallows, it was difficult to cross the beach in droves. The raft went down the river. Due to the small curvature radius of the channel at low tide and the influence of cross flow, the raft often hits the beach, which leads to the disintegration of the raft and leads to disaster.
Lishui to Wenxi Waterway Lishui (Dashuimen) to Wenxi Xiahuamen is located in the middle reaches of Oujiang River, with a total length of 86.5 kilometers. The main towns along the route are Fan Shi, Lakou, Jinshui, Wu Liting, Zhenbu, Haikou, Shimendong, Gaoshi, Zhixitou, Chuanliao, Xishi, Qingtian, Ren Xu and Wenxi Street. This section of the waterway is turbulent in flood season and shallow in dry season, making navigation difficult. The total drop of this waterway is 42m, with an average gradient of 0.05%. There are 60 dangerous beaches in the whole line, with an average of 1.5km. The water depth at the dangerous beaches is generally 0.6 ~ 0.8m, the velocity is generally 1.0 ~ 2.0m/s, and the gradient is generally 0.65,438+0% ~ 0.2%.
The section from Xiahuamen to Hekou is the lower reaches of Oujiang River, with a total length of 76.2 kilometers. It is completely in the alluvial plain, with silt at the bottom and open river surface. The normal water surface width is about1500m, which is a tidal reach, and 500-ton seagoing ships can reach Wenxi Port.
The waterway of Wenzhou Port in the lower reaches of Wenzhou City is divided into the inner waterway (i.e. the downstream waterway of Oujiang River) and the inlet waterway.
The intraoral waterway (downstream waterway of Oujiang River) starts from the upstream of Oujiang Bridge 1km and ends at Qitou of Oujiang River, with a total length of 47.5km ... According to the water depth, it can be divided into four sections from west to east: the first section is from the starting point to the foot of Guogong Mountain, with a length of 12km, a river width of 300 ~1.300 m. The second section starts from Guogongshan, passes through Grey Bridge Shoal and reaches Yangfushan Port Area. The waterway is 6.5 kilometers long, and there is a transitional shoal at the ash bridge, with a water depth of less than 2.5 meters. Ten thousand-ton ships can pass the tide in shallow water; The third section is from Yangfushan to Longwan, passing through Qidutu Beigou or Nangou in the middle. Since June 1985 and 1 1, due to shallow siltation in the south channel of Qidu, the north channel of Qidu has become the main channel, with a length of 14 km, a river surface width of more than 800 meters and a water depth of 2.9 meters at the shallowest point. The length of the river is stable all the year round, and it has a good river correlation system, so it can take advantage of the tide to pass through shallow water 10,000-ton ships. The river channel from Longwan to Qidu Tuwei is relatively curved, with a turning angle of 1200. Qidunan Waterway is an auxiliary waterway, with a length of 13.5km, a river width of1100 ~ 2,000 m, many beaches and shallow beaches, and the water depth at the shallowest point is about1.4m. The fourth section, from Longwan to Qitou, is long1. The shallowest depth of the river-crossing shoal from Panshi to Longwan is more than 4 meters.
There are two estuaries, one is Shatou Waterway, from Qitou in the port to Xiaowuxing Island in Dongtou County. The channel length is 12km, and the shallowest water depth is 2.5m.1970, which is the main channel for port entry. After that, the channel was shallowly silted year by year, and the tonnage of ships entering the port continued to increase. 1973 is adjusted as an auxiliary passage for ships under 3000 tons to enter and leave the port. The other is Huang 'ao Waterway from Qitou to Dongtou, the quarantine anchorage of Qingyu Island, with a length of 14km. The shallow section of Qinglingyu is less than 6 meters deep, 4.5 kilometers west of Wuxianzui and 4.5 meters at the shallowest point. During the Republic of China, this channel was the main channel for ships to enter the port. In recent ten years, the water depth has deepened year by year. 1 972101month1,this waterway is open to foreign ships, and it can pass through turbines of more than 10,000 tons during the tide.
Wenzhou Port, located at the mouth of the lower reaches of Oujiang River, is gradually widened from 1000 meters to 5000 meters from west to east. Jiang Xinyu, Qidutu and Hannah Quinlivan Island live in Hong Kong in turn. The mountains behind the north bank are undulating, and there are 103 islands in Dongtou Island outside the estuary. The whole territory is wide in water depth and calm, and it is a natural port with both estuary port and bay port. Wenzhou Port is located in the middle of China's coastline, with the north-south radiation in the middle. The main coastal ports are symmetrically distributed: 320 nautical miles from Shanghai Port in the north and 2 19 nautical miles from Ningbo Port; It is 0/92 nautical miles from Fuzhou Port/KLOC-,393 nautical miles from Xiamen Port and 203 nautical miles from Keelung Port in Taiwan Province Province. Many ports in Japan, South Korea, Southeast Asia and Hong Kong are distributed on the north-south fan-shaped sea surface of Wenzhou Port. The Oujiang River is 78 kilometers long from Wenxi to Qitoujiao, which is the estuary section. From Wenxi to Mei 'ao, it is 25 kilometers long, and the riverbed is mainly shaped by runoff, which is relatively stable. From Mei 'ao to Longwan, the total length is 38 kilometers. There is a strong interaction between runoff and tidal current, and the river width is also rapidly enlarged. At the middle tide, Mei 'ao River is 485 meters wide and Longwan reaches 2400 meters. Inside the river, the beaches are staggered and there are many beaches, and tributaries flow into nanxi river, so the riverbed changes greatly. Longwan to Koumen, 15km, is basically controlled by tidal current, with wide river surface and stable riverbed, which is limited by some rocky mountain mouths.
Seawall construction
According to Jiajing's Wenzhou Fuzhi, during the Zhenyuan period of Tang Dynasty (785 ~ 805), in view of the long-term neglect of river flood control, people were ordered to build dikes at the boundaries of Lecheng (now Yueqing County) and Hengyang (now Pingyang County) to take farmland and eliminate waterlogging. During the Song Dynasty (1174 ~1189), the east-west levee of Yueqing Huanghua was built and later generations built it. From east to west, it is Huanghuatang, Zhiguangtang, Chenjiatang, Zhujiatang, Baihe Tang, Fakongtang, Pujue Tang, Badutang and Eleventh. The Wan Zhi Pond and Tianjiang Pond from Shi Chong to Guantou were built, with a length of 1.227 feet, and the Guantou Pond, Qian Qian Pond and Xiangpu Pond from Guantou to Bailu Island were built with a length of 1.325 feet. On the south bank of Oujiang River, Antang was built in the second year of Hongzhi in Ming Dynasty (1489), with a length of 700 feet. Shachengtang, a long beach, was built in Jiajing period of Ming Dynasty (1522 ~ 1566), starting from Changsha in the south and reaching Shacun in the north. The pond is 26 19 feet long and is made of stone. In the 13th year of Qing Qianlong (1748), Changsha Hall was built, starting from Furong Rock in Yidu in the south and reaching outside Sanduning Village in the north, with a length of 4,706 feet. Shanbeitang, on the other hand, starts from Sanwutianma Road in the south and reaches Sidu Sancuo in the north, with a length of 1050 zhangs.
Most seawalls built in ancient times have low standards and low flood control and tide resistance, especially during the late Qing Dynasty and the Republic of China, seawalls were in disrepair for a long time and were out of control. After the founding of People's Republic of China (PRC), seawalls were completely renovated, heightened and reinforced in 1950s. From 1964 to 1966, Hannah Quinlivan 64 Pond and Tianhe Phase I seawall were built in Wenzhou suburb. In the 1970s, two standard ponds, Longwan and Zhuangyuan, with a total length of 6.9 kilometers, were built successively. By the end of 1990, the total length of seawalls has been11km in coastal areas such as Ouhai, Lucheng, Longwan and Yueqing, with 27 1400 mu of cultivated land and 465,300 people protected. Among them, seawalls protecting 10,000 mu of farmland and population of more than 10,000 people are: Luchengtang, starting from Du Yu and ending in Xiaxin soil, with a length of16.17 km; Longwantang, starting from Xiaxintu and ending at Longwantang, is 14.42km long, Yongqiangtang, starting from Longwantang and ending at Mouse Mountain, with a length of 32.4km Lingkuntang, built around Hannah Quinlivan Island, with a total length of17.6km; Guantoutang, starting from Wuniuzha and ending at Guantou, is1.1km long; Jiang Shen pond, from west to east, is 4. 14km long. Xindoumen pond, starting from Tianwanjiao and ending at the south gate of Panshi, is 2.73 kilometers long. Panshitang starts from the south gate of Panshitang and ends at Hengheba, with a total length of1.92km..
Reclamation of beaches
Reclamation and seawall construction complement each other. With the siltation of beaches and the outward migration of seawalls, the reclamation area is expanding. The early coastline of Oujiangkou started from Wenruitang River in the east, and reached Leyutang River in the north, from Kangxi to Guangxu in the Qing Dynasty. The coastline moved to the east of Yongqiangtang River in Ouhai County in the south, and moved to Huanghuatang, Panshitang and Sanyutang in the north. Longwan in Wenzhou City, Yongqiang and Wudong in Ouhai County, and the east of Liushi in Yueqing City are all the results of beach siltation and long-term human reclamation.
After the founding of the People's Republic of China, the coastline extends outward at the rate of 10 ~ 20 meters per year, and reclamation is carried out every three to five years. In 1950s and 1960s, the main reclamation projects were Gaotan, including Hannah Quinlivan 64 Pond, Tianhe Phase I and Haibin Phase I, all of which were built above 1000 mu. In the 1970s, there were six reclamation projects with an area of more than 1000 mu, including Sanjiang, Tianhe Phase II, Hannah Quinlivan 74 Pond, Hannah Quinlivan 75 Pond, Seaside Phase II and Phase III, which developed from high beach reclamation to low beach reclamation. 1978 to 1979, the first-stage project of blocking the river and promoting siltation at the south exit of Hannah Quinlivan Island was implemented, with a total investment of1030,000 yuan, with a total rockfill of 233,000 cubic meters and a submerged dam length of 278.5 meters. After the implementation of the project, the siltation at the south exit reached 4.36 million cubic meters in 10, and the effect of promoting siltation was good. By the end of 1990, 46,000 mu had been reclaimed on both sides of the estuary.
Port construction
Wenzhou Port at Oujiang Estuary is located between Ningbo and Fuzhou, with superior geographical location and water environment. Tang and Song Dynasties began to flourish, and it was an important port for foreign trade at that time. In the Ming dynasty, the "sea ban" was implemented and the port declined. In the second year of Guangxu reign (1876), it was listed as a foreign trade port, and Wenzhou Customs was established the following year, and the port was restored. After the founding of People's Republic of China (PRC), a comprehensive opening port was built. There are 62 docks and 76 berths, with a total length of 4,266 meters. The original largest berth was the 5,000-ton Yangfushan 1 Wharf. 1989, 10,000-ton general cargo berths 1 each and multi-purpose berths 1 each have been built in Longwan Port Area. 1990, Wenzhou Power Plant has built a 20,000-ton coal berth, and there are also berths in the rocky waters. The total annual throughput of Hong Kong is 4.97 million tons.
Due to frequent beach sports, the waterway of Oujiang Estuary is changeable. Since the opening of Wenzhou in the second year of Guangxu in Qing Dynasty (1876), the water depth from Ximen to Shuomen has reached 5.5 ~ 6.7 meters. After two major typhoons and floods in the first year of the Republic of China (19 12) and 15 (1926), it was originally changed from Jiang Xinyu. After the founding of the People's Republic of China, dredging was carried out twice in 1964 and 1968, but the effect was not great. In order to find out the evolution law and regulation scheme of the tidal estuary of Shanxi, Nanjing Institute of Water Resources made a scale model of Oujiang estuary. After repeated experiments and research and demonstration, it is decided to adopt the regulation scheme of stabilizing river regime and controlling the main flow direction. Since 197 1, the navigation channel has been regulated for many times: 197 1 year, with 500,000 cubic meters of riprap, 2 downstream dams, submerged dams 1, with a total length of 51. At the same time, a deep trench with a length of 4 150m and a width of 60m was excavated in Nanjiang, and the dredging amount was1190,000m3, so that the water depth of the wharf front in Shuomen and Ximen of Nanjiang gradually reached more than 5m. 1972, east and west groins were built at the foot of Guishan, the mouth of nanxi river on the north bank of Oujiang River, and the water flow was brought to the south bank, scouring the riverbeds of An Lan and Zhenhua port areas, and deep grooves with a length of 2525m and a width of120m were dug at the front of each wharf, so that the water depth at the front of An Lan wharf recovered to more than 5m, and the threshold sill gradually disappeared 1976. The renovation project, * * * investment of 7 million yuan. After the founding of New China, water conservancy projects have been vigorously built. At present, 289 large and small reservoirs have been built in Oujiang River Basin, including 22 large and medium-sized reservoirs with a storage capacity of100000 cubic meters. Many small hydropower stations were built in the late 1950s. In 1960s and 1970s, a large number of small backbone hydropower stations were built. Since the 1970s, the policy of "self-construction, self-use and self-management" has been implemented, and the construction of small hydropower has flourished. In the 1980s, a large hydropower station in Jinshuitan and a medium-sized hydropower station in Shitang were built in Longquan reach of the main stream. In 1990s, Yuxi medium-sized hydropower station was built. Tankeng Hydropower Station, the first high dam in East China in the new century, was successfully completed and stored.
Before the founding of New China, there was not a reservoir with a storage capacity exceeding 654.38+10,000 cubic meters in the basin. After the founding of New China, the management and development of Oujiang River changed from single prevention to comprehensive development and utilization of irrigation, water supply, shipping and tourism. By the end of 2008, 33 large and medium-sized reservoirs had been built, including 2 large reservoirs, namely Jinshuitan Reservoir and Tankeng Reservoir, with a total storage capacity of 6.24 billion cubic meters. 436 hydropower stations have been built, with a total installed capacity of 7 1.53 million kilowatts, including 1 hydropower station, with an installed capacity of 1 10,000 kilowatts and an installed capacity of 520,000 kilowatts. The situation of large and medium-sized reservoirs in Oujiang River Basin The total storage capacity of the river where the project name category is located 10000 cubic meters. Main functions of rainwater collection area (square kilometers) Power generation in Dalongquanxi 139300 of Jinshuitan Reservoir, flood control, shipping and fishery 276 1 Dalongquanxi 4 15000 of Tankeng Reservoir. Flood control and irrigation 3330 minutes ago, the reservoir medium-sized Baishixi 2340 irrigation, flood control, water supply and power generation 38.7 Baishi Reservoir medium-sized Baishixi 1300 irrigation, flood control, water supply and power generation 48.5 Jinkeng Reservoir medium-sized Chuanliao Port 2040 mainly generates electricity. Irrigation and aquaculture 97.3 Dayikeng Reservoir Medium-sized Dayikeng Source 2840 mainly generates electricity 6 1.8 1 Beixi Reservoir Medium-sized Dayuanxi 3820 mainly generates electricity, taking into account flood control and aquaculture 132 Wuxi Reservoir Medium-sized Yun Yun Creek1/70 Irrigation and flood control mainly 29.7 Gao Xi Reservoir. Flood control and power generation 26 medium-sized Panxi 1688 power generation and flood control in Dayang Reservoir 36.94 medium-sized Jinxi 1973 power generation and flood control18 medium-sized Quxi 1350 water supply, irrigation and flood control in Yeung Yi Reservoir1Kloc. .5 Yuxi Reservoir Medium-sized Water Supply and Shipping 3407 Medium-sized Longquanxi 1485 Power Generation 86.2 Zhang Yan Primary Medium-sized Longquanxi143 Power Generation 109 Dayankeng Reservoir, Medium-sized Nanyang Stream 125 Power Generation, Breeding and Water Supply Downstream125. Flood control and irrigation 23.65 Zeya Reservoir medium-sized Pushuhe 57 13 flood control, water supply 102, main power generation secondary medium-sized Songyinxi 1346, irrigation and flood control 2 15, main power generation primary medium-sized Songyinxi 5230, Irrigation and flood control 185 Wu Dong reservoir medium-sized Songyinxi 1460 water supply combined power generation 53.2 Yaxi reservoir medium-sized small Anxi 3000 power generation 184 standard reservoir medium-sized stream 2 159 power generation 30. 1 Yingchuan reservoir medium-sized stream 373 1. 99 medium-sized streams in Shuangkengkou Reservoir 1470 for power generation 38 medium-sized streams in Zuoxi I Reservoir 138 5438+0473 for irrigation, combined with power generation 47.2 Huangcun Reservoir medium-sized Yan Xi 1845 for urban water supply and power generation 150.7.
Tongji Weir, located near Yantou Village, Bihu Town, Liandu, Lishui City, Zhejiang Province, was built in Xiaoliangtian Prison in the Southern Dynasties for four years (AD 505), with a history of 1500 years. It is the oldest large-scale water conservancy project in Zhejiang Province, and 1962 was listed as a provincial cultural protection unit. On June 25th, 20001year, Tongji weir, as an ancient building from Southern Dynasties to Qing Dynasty, was approved by the State Council to be included in the fifth batch of national key cultural relics protection units. 20 14, Tongji weir was successfully selected as the world irrigation project heritage. The whole water conservancy project, together with the inscription, is valuable information for studying ancient water conservancy projects in China. Since the Song, Yuan and Qing Dynasties, it has been rebuilt and renovated many times. The arch dam is 275 meters long, 25 meters wide and 2.5 meters high. At first, it was a wooden fence structure, and it was changed to a stone dam in the Southern Song Dynasty. It is a water conservancy project with both water storage and drainage functions. The rainwater harvesting area in the upper reaches of Tongji Weir is 2 150 square kilometers, which can intercept more than 200,000 cubic meters of weir and canal every day and irrigate more than 40,000 mu of grain fields in the south-central part of Bihu Plain. The ancients took advantage of the situation and built a dam here to prevent water from entering the canal, which could make the canal water flow from high to low and irrigate the whole plain. The dam is 500 meters west of Dagang Head at the confluence of Daxi and SongSilverstream. The southern end of arch dam arch foot is at the foot of Yanshan Mountain, and the northern end is on the levee on the east bank of the diversion canal. Thousands of thousand-year-old camphor trees were planted on the levee, which made the foothold at both ends of the dam more stable. At the same time, the Daxi water flow coming down from Longquan Port will certainly rotate at the confluence, and part of the water flow will rush to the dam to the west, which can offset the impact of the SongSilverstream flood on the dam. This is one of the reasons why the Tongji Weir Dam has been enduring for thousands of years.
Gufangtang has a history of 1700 years, and it is the earliest recorded water conservancy project in Oujiang River Basin. Gufangtang is located in Shangdang Village, Huyuan Township, Jinyun County, Zhejiang Province, at the top of Gufangtang near Shang Ping Village, with an altitude of nearly1.200m.. It is the birthplace of Panxi, the main tributary of the upper reaches of Oujiang River. Gufangchi was founded in the second year of Wu Chiwu in the Three Kingdoms (239) and rebuilt on August 15th in the eighth year of Yongle in the Ming Dynasty (14 10). According to records, an ancient stone tablet stands beside the pond. The old ancient dam is about 18 meters high and 26 meters long, with a storage capacity of 65438+ 10,000 cubic meters. After the dam was rebuilt in 1970, it is now 38 meters high, 0/30 meters long and 0/280,000 cubic meters in storage capacity. It mainly irrigates more than half of Huyuan Township such as Shangdang Village, Shang Ping Village, Jiaokeng Village and Hucun Village. Now there is an impact hydropower station at the foot of Gufang Mountain, which gives full play to the comprehensive role of power generation and irrigation.
Tankeng Hydropower Station is located in the middle reaches of Oujiang tributary in Lishui City, Zhejiang Province. Most of the reservoir area is in Jingning She Autonomous County, and the power station is in qingtian county. Tankeng Hydropower Station started the main project on June 3, 20041day, and officially stopped to store water on April 29, 2008. On August 15, 2008, Tankeng Power Station 1 Unit was connected to the grid for power generation; on October/0/2, 2009, Tankeng Power Station Unit 2 was connected to the grid for power generation; on July/0/0, 2009, Tankeng Power Station Unit 3 was connected to the grid for power generation. Tankeng Hydropower Station has a total storage capacity of 410.50 billion cubic meters, an installed capacity of 600,000 kilowatts, and an annual power generation of 65.438+0.35 billion kWh. The crest elevation of He Lan Dam is 17 1m, the crest length is 506m, and the maximum dam height is 162m, which is the highest dam in East China.
Jinshuitan Reservoir is located in the upper reaches of the Oujiang River in the north of Yunhe County, with a drainage area of 276 1 km2. It is the first project to develop the hydraulic resources of the main stream of the Oujiang River. It is a water conservancy project that mainly focuses on power generation and has comprehensive benefits such as flood control, irrigation, shipping and the development of freshwater fisheries. Commencement in June 198 1, dam completion in June 1986. The dam reservoir has a total storage capacity of 65.438+39.3 million cubic meters and an installed capacity of 300,000 kilowatts. All six units were put into operation at 1988, providing East China Power Grid with 250,000 kilowatts of peak-shaving capacity and 50,000 kilowatts of load reserve and accident reserve capacity, and the average power generation for many years can reach 490 million kWh. The reservoir covers an area of 34.2 square kilometers, which can increase the fish culture area by 40,000 mu. After the reservoir is impounded, the downstream river flow can be adjusted, and the flood peak flow once every 20 years can be reduced by 57%, which plays an important role in improving the flood control capacity of Lishui City and Bihu Town and protecting 70,000 mu of farmland in Lishui and Bihu River basins.
Shitang Hydropower Station is the largest medium-sized riverbed hydropower station in Oujiang River Basin. It is the secondary power station of Jinshuitan Hydropower Station, and the distance between the two stations is 22 kilometers. Shitang Power Station is located in Yunhe County, with a drainage area of 3,234 square kilometers above the dam site and a catchment area of 473 square kilometers in Jinshuitan. The reservoir is a river type with a total storage capacity of 83 million cubic meters and daily regulation. The total installed capacity of the power station is 78,000 kilowatts, and the average annual power generation for many years is 6.5438+89 million kWh. The power station hub consists of river dam, power station, switching station, booster station and navigation raft facilities. The dam is a concrete gravity dam, with crest elevation 104.9m, maximum dam height of 38.9m, and total crest length of 255m.