Taihu Lake is located inYangtze River deltaThe southern edge of the lake, known as Zhenze and Juqu in ancient times, also known as Five Lakes and Lize, is one of the five largest freshwater lakes in China, ranking third[1-2]Between 30 ° 55'40 "~31 ° 32'58" N and 119 ° 52'32 "~120 ° 36'10" EWuxi, Zhejiang to the southHuzhou, west of JiangsuChangzhouJiangsuYixing, near Jiangsu in the eastSuzhou。[3]Jiangsu Province exercises administrative jurisdiction over the whole territory of Taihu Lake.
Taihu Lake covers an area of 2427.8 square kilometers, with a water area of 2338.1 square kilometers and a total lake shoreline of 393.2 kilometers.Its west and southwest are hilly mountains, and its east is dominated by plains and water networks.[3]
Taihu Lake is located in the subtropical zone, with a mild and humid climate and a monsoon climate.Taihu Lake is crisscrossed with many river mouths, and there are more than 50 main rivers in and out.[3]
The Taihu Lake water system flows from west to east, with an average annual runoff of 7.5 billion cubic meters and a storage capacity of 4.4 billion cubic meters.There are more than 50 islands in Taihu Lake, of which 18 are inhabited.[3]In 2022, six departments including the National Development and Reform Commission and the Ministry of Natural Resources issued a new round《Overall Plan for Comprehensive Treatment of Water Environment in Taihu Lake Basin》。[21]
Chinese name
Taihu
Foreign name
Taihu Lake
geographical position
Southern Jiangsu Province, northern Zhejiang Province, middle and lower reaches of the Yangtze River
The formation of Taihu Lake is due to the siltation of the river.Yangtze River deltaTaihu LakeYangcheng Lake、Dianshan LakeThe group of lakes was originally a big bay connected with the sea, becauseYangtze RiverAndQiantang RiverIt extends eastward and bends back, so that part of the sea surface is surrounded by the inner sea and becomes the inner sea. The water from the mountains on both sides is continuously injected, diluting the water in the inner seaFreshwater lake。[4]
Tectonic theory
The neotectonic movement of the crust in the Taihu Lake area caused the subsidence of the Taihu Lake plain, the diversion of the river, and the diversion of the Jingxi River system to the east. The fault basin became a catchment basin, and gradually became several small marsh lakes, and later gradually formed the Taihu Lake.
Meteorologic theory
The continuous heavy rain for thousands of years in ancient times, and the annual precipitation in some years even reached 6 billion tonslow-lying landA large amount of water accumulated year after year, thus forming the present Taihu Lake.
Storm flow theory
The climate anomaly from 4000 to 6000 years ago, the continuous formation of large storm vortexa furious stormAs a result, the swamp shallow depressions in the Taihu Lake area have accumulated more water, and the water area is expanding day by day, forming the Taihu Lake.
River siltation theory
Spring Scenery of Taihu Lake
During the Yumu Ice Age at the end of the Pleistocene in the Quaternary, 20000 to 15000 years ago, the sea water retreated eastward, and the bay of the ancient Taihu Lake disappeared. The Taihu Lake area was connected to the East China Sea shelf, becoming a vast alluvial plain of the ancient Yangtze River Delta. The plain vegetation was temperate grassland or sparse forest grassland.In the middle Holocene (7500-2500 years ago), as the climate became warmer, the sea level rose to near the current sea level.becauseYangtze RiverAnd the formation of the sand mouth of Qiantang River,Taihu PlainIt becomes a large catchment.Jingxi River and Tiaoxi River flowing into the sea from the northeast into the Yangtze River in the western mountainous area were diverted into this dished depression due to the flooding of the lower reaches of the river, the decrease of gradient, the poor discharge of the river channel into the sea, and the serious siltation of river mud and sand.The back flow of the sea tide and the rise of the groundwater level in the plain caused the ponding in the low-lying land to become swampy, forming scattered small lakes.The area of each small lake gradually expanded to form a large lake.In addition, the river channel leading out of the lake on the east bank gradually silted up, the lake water accumulation increased, and the wind, waves and currents in the lake eroded the lake bank, further expanding the lake area, thus becoming the current Taihu Lake.
Volcanic eruption theory
Through years of sampling and identification and field geological survey of Sanshan Island in Taihu Lake, it is found and confirmed thatvolcanoThe existence of: there are explosive breccia, primary secondary eruption tuff breccia and weakly fused glassy tuff in Sanshan Island.The north and west of Sanshan Island are covered with volcanic breccia and volcanic bombs, which have been silicified intoFlint、Chalcedony、agateA geological section of volcanic eruption was found at Dongpo Xiaoshan, and the eruption time was at the end of Cretaceous 50 million years ago.Volcanic activity is the result of deep magmatic activity.Magmatic volcanic activity has reduced the underground heat pressure and bulk density of Taihu Lake and its surrounding areas, resulting in negative pressure, which has brought about the slow subsidence of the area in the Cenozoic era. Taihu Lake and its surrounding lakes are land subsidence lakes formed by volcanic eruptions of the same origin and cause.
Meteorite attack theory
This theory is divided into "meteorite impact origin theory" and "comet explosion origin theory".
Suzhou Bay Heart shaped Island is located in the Happy Village of Taihu Lake[20]
According to the meteorite impact theory, 50 million years ago, a huge meteorite hit the ground from the northeast, causing a huge impact equivalent to 10 million Hiroshima atomic bombs, leaving more than 2300 square kilometers of meteorite crater, namely Taihu Lake.
According to the comet explosion cause theory, at about 7 ka B.P., a comet crashed into the Taihu Lake area from northeast to southwest and exploded in the sky, forming a shock wave that hit the surface and formed a modern Taihu Lake basin.Shihu Lake is part of Taihu Lake.[5]
The latest research results of the Department of Earth Sciences of Nanjing University: the origin of Taihu Lake may be related to air explosion, forming a large number of iron rich nuclei with unique shapes.These iron rich nodules may be impact fallout, which are mainly distributed in the symbolic mud layer above the hard loess layer at the bottom of Taihu Lake and its surrounding lakes.The modern Taihu Lake basin was formed around 7 ka B.P.[5]
Dongting East Mountain and West Mountain were the two largest mountains in the lakeislandsLater, due to the siltation between Dongshan and Mudu, the beach expanded. By the middle of the Qing Dynasty, the island andSandbarThe connection makes East Taihu Lake a big bay of Taihu Lake.In the past one or two hundred years, due to the increased siltation on the east and northwest banks of East Taihu Lake, and the reclamation of lake beaches, East Taihu Lake has actually become a narrow and shallow dry lake area with serious water blocking.The changes of the modern Taihu Lake are most prominent in the East Taihu Lake area.
In the 1960s and 1970s, Taihu Lake and its surrounding lakes were planted and farmed around the lake,lakeThe area decreased by 13.6%, and 165 lakes disappeared or basically disappeared, with a total area of 161 square kilometers.Among them, Taihu Lake and Gehu Lake are the most prominent. Majishan Island in the northwest of Taihu Lake has been connected to the land due to reclamation of land from the lake.The north, east and south of the lake across the lake have greatly reduced the original lake surface due to the accelerated enclosure of the lake.
Watershed characteristics
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geographical position
The boundary of Taihu Lake is between 30 ° 55'40 "~31 ° 32'58" north latitude and 119 ° 52'32 "~120 ° 36'10" east longitude. It is located in the south of Jiangsu Province, bordering Wuxi in Jiangsu Province in the north, Huzhou in Zhejiang Province in the south, Yixing in Jiangsu Province in the west and Suzhou in Jiangsu Province in the east.[6]
topographic features
To the west and southwest of Taihu Lake are hills and mountains, and to the east areplainAnd water network.[6]
climate
Taihu Lake is located in the subtropical zone, with a mild and humid climatemonsoon climateIn summer, affected by tropical ocean air mass, southeast wind prevails, and it is mild and rainy;Controlled by the northern high-pressure air mass in winter, northerly wind prevails, cold and dry.The annual average temperature is 16.0 ℃ - 18.0 ℃, and the annual precipitation is 1100-1150mm.[6]
Water system composition
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Overview of Lake Area
The water area of Taihu Lake is 2338 km2. The lake surface is shaped like a crescent protruding from the west. The lake shore in the southwest is smooth and circular in shape. The lake shore in the northeast is full of twists and turns with many bays and mountain nails.The lake is 68km long and 56km wide at most.Due to sediment deposition and artificial reclamation, some islands are connected with East and West Tingshan respectively, while those near the shore are connected with the lake shore to form a peninsulaislands48, with Dongting Mountain in the west covering the largest area of 75 km2.[7]
Upstream water system
The catchment area in the upper reaches of Taihu Lake is 19000 square kilometers. In ancient times, there were two major water systems, Tiaoxi River and Jingxi River, flowing into the lake. So far, there has been little change.The Tiaoxi River system originates from Tianmu Mountain in Zhejiang Province, with the east and west Tiaoxi as the largest.Jingxi water system originates from Yili Mountain and the east foot of Maoshan Mountain, and can be divided into Nanxi water system, Taoge Lake water system, Jiangnan Canal water system, flowing eastward into Taihu Lake.There are south-north regulation channels between the water systems.Jiangsu ProvinceHuxi area in the territory intercepts water to the north of Jiangnan Canal, and the drainage area of the water system entering the lake is 6081 km2.
Nanxiriver systemThe main rivers ofXu River(formerly known as Xuxi River)Nanhe River、Nanxi River。Xuhe River is connected to Gucheng Lake in the west, connecting the Taihu Lake water system and the Shuiyang River water system. Dongba and Xiaba were built in the Ming Dynasty to block it. Xiaba is 30 kilometers long, passing through Dingbu in the east, passing through Wangjia in Hexin Township, and crossing into Liyang County to connect with Nanhe River.The South River, formerly known as Xuxi, was also known as the Yili Canal during the Republic of China. After the founding of the People's Republic of China, it was called the South River. It starts from the junction of Chunli to the junction of Yili and Duji Bridge in the west, with a total length of 45.5 kilometers. Along the line, Meizhu River, Daxi River, Lidai River (commonly known as the Daibu River), etc.Nanxi River flows from the crossing of the Jiqiao Bridge at the junction of Yixing and Lijiang to Xidang via Xushe, passes through Yixing County to Dongdang, and flows into Taihu Lake at Dapu. The total length is 42 kilometers, and it is successively joined by Xixi River, Taoxi River, Zhonghe River, and Lihe River.After the founding of the People's Republic of China, four large and medium-sized reservoirs were built in the upper reaches of Daxi River, Daibu River and Youxi River.The Daxi River is connected to Daxi Reservoir (with a storage capacity of 171 million cubic meters) and Qiansong Reservoir (with a storage capacity of 15.96 million cubic meters).The Daibu River is connected to the Shahe Reservoir (with a storage capacity of 109 million cubic meters).Yongxi River is connected to Hengshan Reservoir (with a storage capacity of 102 million cubic meters).
The Taoge Lake water system is located between the Jiangnan Canal, the Nanhe River and the Nanxi River, connecting the water from the eastern foot of Maoshan Mountain to the westTao LakeAfter the Gehu Lake is regulated, the water is poured into Taihu Lake.Taohu Lake, also known as Changdang Lake, spans Jintan County and Liyang County, with an area of 90 square kilometers and a volume of 100 million cubic meters.Gehu Lake spans Wujin County and Yixing County, with an area of 164 km2 and a volume of 210 million cubic meters.In the west of Taohu Lake, there are mainly Tongji River and Beihe River.Out of Taohu Lake, Huangli River, Beigan River and Zhonggan River flow into Gehu Lake.In addition, Xiaxi River and Biandan River flow into Gehu Lake from the northwest.Out of Gehu Lake, Taige Canal, Caoqiao River, Yincun Port, Zhandu Port, etc. flow into Taihu Lake.
There are south-north flood diversion, river diversion and navigation regulation channels between the river systems. There are Danjin Licao River, Zhaocun River, Mengjin River and Wuyi Caohe River between the Jiangnan Canal and Nanhe River and Nanxi River.Taoge Lake andjiangnan canal Between them are Xinhexi River, Xili Caohe River, etc.[8]
Downstream water system
Taihu Lake is one of the five largest freshwater lakes in China and the largest lake in Jiangsu Province. It was called Zhenze in ancient times, also known as Lize.The southern edge of the lake area is located on the boundary line between Jiangsu and Zhejiang provinces. The lake covers an area of 2338 km2, with a general lake bottom elevation of about 1.10 meters.The annual average water level is about 3m, and the lake volume is 4.87 billion cubic meters.At the water level of 4m, the lake has a volume of 7.3 billion cubic meters.When the water level is 4.5 meters, the lake volume is 8525 million cubic meters.In ancient times, there were more than 260 rivers in and out of Taihu Lake, including Jingxi Baidu in the northwest and seventy-four Tiaoxi in the southwest;In the southeast, there is Zhenze Port 72;In the east, there are eighteen ports of Wujiang, which are the port of exit from the lake.Due to years of siltation and artificial diversion, there are less than 200 lakeside river ports.Ditang was built along the lake in the Eastern Jin Dynasty, and Wujiangtang Road and other river lake separation projects were built in the Tang and Song Dynasties.In 1958, part of the Taihu Lake levee was built, and in 1977, the Taihu Lake levee (also known as the Taihu Lake control line) was continued.The total length of the coastline around Taihu Lake is 410 kilometers, of which the coastline in Jiangsu is 350 kilometersmountains and hillsIn the region, the causeway around the lake is 243km long, which is divided into the east causeway and the west causeway.Huxi Causeway, 58 kilometers long, stretches westward from Zhihu Port, Wuxi County, to the east and west Tiaoxi River, Wuxing County, Zhejiang Province;The Hudong Causeway is 185 kilometers long from Liangxi, Wuxi County, eastward, southward along the lake, through Xuzhou, across the Taipu River, across the Jiangsu Zhejiang provincial boundary to Wuxing.
The channel from the lower reaches of Taihu Lake to the river and seaWusong River、Dongjiang、Loujiang, collectively referred to as the three rivers of Taihu Lake, discharge water to the east, south and north respectively.Around the 8th century, Dongjiang River and Loujiang River were annihilated one after another.Since the 11th century, Wusong River has also been silted up and narrowed quickly.After the water from the upstream flows into Taihu Lake, it flows into the Yangtze River through the eastern depression of the lake.In the first year of Yongle in the Ming Dynasty (1403), Fanjiabang was opened in the east of Shanghai County, connecting the Huangpu River on the top and the Yangtze River on the bottom.In less than half a century, the Huangpu River has become a deep and wide river, which has become the main outlet for drainage in the lower reaches of Taihu Lake. The Wusong River has silted up as a tributary of the Huangpu River.In 1958, the Taipu River was excavated, connecting Taihu Lake on the top and Huangpu River on the bottom.There are three branches of Huangpu River above Mishidu, with Xietang, Maohe River and Road Blocking Port in the north, which are connected with Dianshan Lake;In the middle is the Yuanxiejing, and in the upper is the Yu Huitang;To the south is Maogang, which is connected with the water from Hangzhou and Jiahu.It is 113 kilometers from Mishidu to Wusong.
The Hudong depression in Jiangsu Province flows into the Huangpu River. The north of the Taipu River is called the Dianmao River System, and the south of the Taipu River is called the Punan River System.The area from Jiangnan Canal to the north of Liuhe River can be divided into Yangcheng River System, Chengxiyu River System and Huxi River System according to the terrain.
Taihu
The Dianmao River system covers an area of 1500 square kilometers, including the east of Taihu Lake, the south of Loujiang Huning Railway and the north of Taipu River.There are many lakes and water networks in the area, which communicate with each other.Dianmao Lake Group mainly includes Dianshan Lake, Chenghu Lake and its surroundingYuan dang、White clam lake, ChangbaidangBailian Lake, Jinji Lake, Dushu Lake, etc. The main rivers are Wusong River, Jishuigang, Niuchangjingtang, Badang River, etc.Wusong River meanders across the north, starts from Songling Town, Wujiang County in the west and connects with Taihu Lake, flows through Wuxian County and Kunshan Mountain in the northeast, enters Shanghai and is called Suzhou River, and enters Huangpu River at Waibaidu Bridge, with a total length of 125 kilometers (81.9 kilometers in Jiangsu Province).Many river ports on the north bank, Dushu Lake, Jinji Lake, Loujiang RiverLiuheConnected, many river ports on the south bank are connected to Chenghu Lake and Dianshan Lake.Chenghu Lake covers an area of 45 square kilometers, with a volume of 80 million cubic meters. It carries water from the west and north to the southeast and discharges into Dianshan Lake.Dianshan Lake covers an area of 67 km2, with a volume of 130 million cubic metersChenghu LakeIn addition to the incoming water, there is a rapid water port in the west, and most of the main rivers out of the lake are blocked except the road blocking port.There are Mingjingdang, Changbaidang and Bailian Lake between Chenghu Lake and Dianshan Lake.
Punan water system, bounded by Taipu River in the north and connected with Hangjiahu Plain in the south, covers an area of 553 km2.In addition to the Taipu River, there are Jiangnan Canal, Pond and Lanxi Pond.The Taipu River starts from Shijiagang in Wujiang County in the west and connects with Taihu Lake, and flows into Huangpu River, with a length of 57.5 kilometers.Since 1958, after several excavations, 40.5km of water has been flowing in Jiangsu Province, and the next 17km has not been excavated.Along the line, there are many lakes, such as Ant Yang, Peach Blossom Yang, Fen Lake, Maxie Lake, Qian Shengdang, etc., and they cross the Jiangnan Canal at the level of Pingwang. They are the main rivers discharging Taihu Lake flood into the Huangpu River.
Yangcheng River system is located to the east of Wangyu River and north of Loujiang River to Liuhe River, with an area of 2537 km2.Loujiang River, Liuhe River, Yanglintang, Qiputang, Baimao Pond, Changhu River and other rivers in the area drain into the river from west to east, and Yantie Pond runs through the rivers from northwest to southeast.Salt iron pondTo the east, it is an alluvial plain along the river, with high terrain;To the west of Yantietang is Yangcheng Lake Group, which is low-lying and has dense river network.Yangcheng Lake covers an area of 113 square kilometers, with a volume of 320 million cubic meters, surrounded by Kuncheng Lake, Shengzedang, Bacheng Lake, Puppet Lake, Eel Lake and other lakes.Loujiang River, one of the three drainage rivers of the ancient Taihu Lake, flows into the sea from Loumen, Suzhou City, to the east via Kunshan Mountain, and was abandoned around the 8th century.In the second year of the Northern Song Dynasty (1055), Zhihetang was built. After many times of dredging and embankment construction, it sailed from Liujiagang.It was renamed Loujiang during the reign of Emperor Hongzhi of the Ming Dynasty.After the founding of the People's Republic of China, Caolu Village in Kunshan was taken as the dividing point between Loujiang River and Liuhe River when the Liuhe River was expanded in 1958.The Loujiang River starts from Loumen, Suzhou, and flows eastward to Caolu Village, Kunshan County, with a length of 53.1 kilometers and a drainage area of 230 square kilometers.Liuhe River runs from Caolu Village to Liuhe Town in the northeast, with a length of 24 kilometers and a drainage area of 1000 km2.Yang LintangStarting from Yangcheng Lake in the west and flowing into the river in the east, it is 47 kilometers long.Qiputang starts from Yangcheng Lake in the west and goes out of Qiya to the river in the east, with a length of 48 kilometers.The Baimao Pond is 41.3 kilometers long, starting from the small east gate of Changshu in the west, connecting Kuncheng Lake and going out of Baimao to the river in the east.The Changhu River starts from Changshu's Great East Gate in the west and goes out of the wild cats into the river in the east, with a length of 21.8 kilometers.The regulation rivers in the area include Yantietang, Zhangjiagang South Section, Yuanhetang.Yantietang is 95km long from Yangshe, Zhangjiagang to Taicang, crossing into Wusong River at Huangdu, Jiading (10.5km in Changshu in the west section has been silted up, only 84.5km at present).The southern section of Zhangjiagang connects Wangyu River at Yushan of Changshu, crosses Kuncheng Lake to the southeast, passes Hengjing Pond, passes Bacheng Lake, enters Changshu Pond, crosses Lou River, and connects Qingyang Port. It is a regulating channel for water diversion and drainage in the middle of Yangcheng River System and an important channel in southern Jiangsu.Yuanhetang starts from Qimen of Suzhou in the south and ends at Changshu South Gate in the north, with a length of 45 kilometers. It is the western diversion and drainage regulating channel of Yangcheng River System.
The Chengxiyu River system, which extends to Changcheng Highway in the west and Wangyu River in the east, covers an area of 3588 square kilometers.The main rivers in the area are expected to be Yu River, Xicheng Canal, Xingou River, Zhangjiagang, Shiyiwei Port, etc.The Xicheng Canal is 39 kilometers long.The Xingou River is 27 kilometers long.Zhangjiagang is the main drainage channel in the northern highlands from the north of Jiangyin to the west, passing through Zhangjiagang City and entering the river;From north to southeast, it crosses Wangyu River and enters Wusong River. After two times of renovation, it is 121 kilometers long.Shiyiwei Port starts from Jiangyin in the south and flows into the river in the north, with a length of 27 kilometers.The rest are Xigong River, Nanhengtao River, Dongheng River, Taiziwei Port, Qingzhu River, Xibei Canal, Jiuli River, Bodu Port, etc.The south of Wangyu River starts from Shadun near Taihu Lake, passes through Jiangnan Canal and Huning Railway, passes through Caohu Lake in the northeast, and reaches Gengjing River, with a length of 60.2km.
The water system along the river in the west of the lake takes the Changzhen section of the Jiangnan Canal as the main river, which drains northward into the river, with an area of 1900 km2.The main rivers areJiuqu River、Xinmeng River、Desheng River, Zaigang River, Taohua Port, Ligang, etc.The Jiangnan Canal was originally Zhenjiangjing, facing the Guazhouli Canal across the Yangtze River. In 1958, it was diverted from Jianbi to the river, facing the Liuweili Canal across the river.From Jianbi to the west, it connects Lingtang River (the upper part of Lingtang Reservoir), Nantong Xiangcao River, Danjin Licao River, Biandan River and Wuyi Canal, and goes around the eastern edge of Taihu Lake to Zhejiang Province through Pingwang.Also known in JiangsuBeijing Hangzhou CanalThe southern Jiangsu section is 218km long.From Zhenjiang to Changzhou, part of the water from the west of the lake flows northward into the river, or the water from the Yangtze River is diverted to supplement the water source of the west of the lake.Jianbi pumping station was built in 1978 when the canal entered the river, with a drainage and irrigation capacity of 120 cubic meters per second.[8]
hydrographic features
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flow
Average annual output of Taihu LakeRunoffIt is 7.5 billion cubic meters, and the storage capacity is 4.4 billion cubic meters.[6]
water level
averageWater depth1. 9m, with a storage capacity of 4.43 billion cubic meters.The spring rain increases in April every year, and the water level rises to the highest level in July and August. After September, the water level begins to decline. In November and December, it enters the dry season, and the water level is the lowest in January and February of the next year.The highest water level over the years is 4.62m (August 25, 1954), and the lowest water level over the years is 217 meters (February 29, 1956).[7]
water temperature
Annual average of Taihu Lakewater temperature17.1 ℃, the average water temperature in January is 4 ℃, and the average water temperature in July is 25 ℃.Throughout the year, thin ice 1-2 cm thick can only be seen in the lake bay or leeward bank. Only in extremely cold years can the whole lake freeze. In the past 65 years, the whole lake has been frozen only 10 times.[7]
ecological environment
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Pollution
In 1987, 1% of the water quality of Taihu Lake was slightly affectedcontaminated, mainly distributed on the surface of Wuli Lake and at the entrance of Xiaomei Lake;10% of the water surface quality reaches Grade 3, mainly distributed in the coastal waters of Taihu Lake from Sanshan, Maji Mountain, Dapu Port to Wuxi Port and Weigang to Guangfu;89% of the water surface maintains the secondary water quality, which is mainly distributed in the water area in the center of the lake.
becauseWater QualityThe eutrophication of Taihu Lake is aggravated due to degradation, and green "water blooms" often occur.From within the lakenitrogen、phosphorusAccording to the nutrient composition analysis, the indicators are in the middle level of eutrophication and eutrophication.The total nitrogen value was only 0.23mg/l in 1960, 0.85mg/l in 1980, and 1.43mg/l in 1987, 1.6 times of 1980 and 6.23 times of 1960;The total phosphorus value was 0.02 mg/L in 1981, 0.046 mg/L in 1987, and 2.3 times of that in 1981.According to the evaluation of nitrogen and phosphorus indicators, the middle eutrophication and eutrophication area of Taihu Lake has accounted for more than 90% of the total area of Taihu Lake.Due to the high degree of eutrophication along the Taihu Lake in Wuxi, cyanobacteria often breed in summer in recent years, seriously affecting the water quality.[9]
pollution prevention
according toRegulations of Jiangsu Province on the Prevention and Control of Water Pollution in Taihu LakeThe Taihu Lake basin is protected at different levels, and is divided into three protection zones: the Taihu Lake body, the five kilometer area along the lake bank, the ten kilometer upstream river channel into the lake, and the one kilometer area on both sides of the coast are classified as Grade I protection zones;The main rivers entering the lake are 10-50km upstream and within 1km on both sides of the coast;Other areas are Class III protected areas.The specific scope of the first, second and third level protection zones in the Taihu Lake basin is determined byJiangsu Provincial People's GovernmentDelineate and publish.[10]
At the end of May 2007, Taihu Lakeblue-green algaeThe outbreak in a large area caused serious water pollution in the water source area, leading to a water supply crisis for nearly 2 million residents in Wuxi.Subsequently, the State Council made an important instruction to strengthen the control of water pollution in Taihu Lake.Jiangsu Province has also accelerated the progress of water pollution control in Taihu Lake.
By 2011, Jiangsu Province had completed 1050 Taihu Lake control projects.According to the overall national plan for the prevention and control of Taihu Lake and the implementation plan formulated by Jiangsu Province, by 2020, Jiangsu will implement nearly 1800 Taihu Lake prevention and control projects.Jiangsu Province has completed 65.6% of the total by 2011.After comprehensive treatment, the main pollution indicators of Taihu Lake have dropped significantly, but the total nitrogen indicator is 2.74 mg/L, which is not far from the national requirement of 2 mg/L.There is still a risk of sudden water pollution in Taihu Lake.[11]
On February 27, 2024, it was learned from the press conference on the new round of comprehensive treatment effect of Taihu Lake held by the People's Government of Jiangsu Province that in 2023, the water quality of Taihu Lake will reach the best level since 2007, and the safety of summer will be achieved for 16 consecutive years, and the lake center area will reach Class III for the first time.[24]
water conservancy project
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Irrigation project
The Taihu Lake area in southern Jiangsu has 12.9 million mu of arable land, including 1.6 million mu in Huxi and lakeside hilly areas, 6.44 million mu in Taoge, Chengxiyu and riverside plains, and 4.86 million mu in Yangcheng, Dianmao, Xicheng Canal and Huxi polder areas.The whole area is adjacent to the Yangtze River in the north and Taihu Lake in the south. There are many lakes, dense river networks, superior water diversion and storage conditions, and abundant irrigation water sources in general years.Except that there are reservoirs and dams in the hilly area of the west lake to store water and recharge from the rivers and lakes,Plain areaRiver water is mainly used, and lake water is mainly used in polder area.
With the development of ancient agriculture, irrigation continued to develop.Qin and Han DynastiesThe low-lying fields along the lake began to build dikes and dikes, the highlands along the river gradually introduced river water, and the Taoge Plain gradually built ponds.Southern and Northern DynastiesAt that time, large ponds such as Dantang, Wutang and Nanbei Xietang were built to the east of Jintan in the west.Changshu in the east "Gaoxiang has twenty-four riverside lakes, which are accessible to the tide, irrigation and drought free".Sui and Tang DynastiesIn, irrigation and drainage projects were built in Runzhou (Zhenjiang), Changzhou and Suzhou.In the eighth year of Yuanhe in the Tang Dynasty (813), "Mengdu was opened in the west of Changzhou, connecting the Yangtze River in the north and the canal in the south, with a length of 41 miles. The river water was diverted to irrigate 4000 hectares of farmland, and the canal was connected".During the Taihe period (827-835), salt iron ponds were dredged, ponds and ponds were excavated on both banks, weirs, gates and buckets were built widely, and water was blocked in the east of the hillock to irrigate the high fields.At the end of the Tang Dynasty, there were a large number of polder fields in the north of Wusong River, and the keel waterwheel was gradually popularized, so the drought and flood were less than that.During the period of Wu and Yue, we consolidated and improved the polder fields in Tangpu, continued to dredge the twenty-four lakes in Haiyu, and built weirs and sluices in every river and every pond. The scene of "low fields are always free of water, high fields are always free of drought" and "years old and fertile" appeared.In the early years of the Northern Song Dynasty, the drought and flood that once destroyed the gate and abandoned the weir intensified.In the second year of Song Jingxuan (1035), Fan Zhongyan supervised Baimao, Fushan, Hupu, Qiya and other Dapu to facilitate drainage.In the second year of Qingli (1042), Changzhou was opened to all ports along the river and irrigated thousands of hectares of farmland.During the Xining period, the farmland water conservancy law was implemented, and irrigation and drainage projects were restored.Entering the Southern Song Dynasty, the wind of reclamation was growing, and in some areas, there was a situation where Potang Loudu was regarded as a domain of land, where there was no land to store water, and where there was drought, there was no water to bail out.During the Ming and Qing Dynasties, Tongjiang Port and Pu continued to be expanded and dredged, and gates were continuously built to benefit the tide.Due to the limitation of technical conditions, the ancient river gates were built repeatedly, and the opening and closing were ineffective. When the diversion and drainage were lost, the neap tide could not enter, and the spring tide was insufficient.At the end of the Qing Dynasty, dams were built on tributaries to retain the climax.
Taihu
Republic of ChinaDuring the period, in addition to continuing to expand and dredge the river port, Jiangxing built a sluice (Baimao five hole reinforced concrete sluice was built in 1936), and built dams and culverts on tributaries, electromechanical power water lifting irrigation was started.As early as the 34th year of the reign of Emperor Guangxu in the Qing Dynasty (1908), there was a kerosene engine driven keel waterwheel to carry water for irrigation in Xixiang, Wuxi.In the 4th year of the Republic of China (1915), domestic diesel engines were used to drive the keel waterwheel to lift water.After the 9th year of the Republic of China, diesel engine belt was adoptedWater pumpWater lifting, and the emergence of owners operating mobile boats to bag fields and bucket water.In 2013, Zhenhua Power Plant set up an electric irrigation station in Wujin, benefiting 2000 mu.In the 14th year of the Republic of China, Suzhou Power Plant supplied power and began to irrigate 20000 mu of farmland in Wuxian County with mobile electric irrigation boats.In the 20th year of the Republic of China, the National Government's Construction Committee established a model irrigation administration, under which the Wuxi District Office was set up to engage in the electric irrigation construction in Wujin and Wuxi, and Pangshan Experimental Field was set up in Pangshan Lake, Wujiang. In the 23rd to 25th year of the Republic of China, three fixed irrigation and drainage stations were built, with 10 sets of installed machines, a design flow of 2.67 cubic meters per second, and 8600 mu of irrigation fields.In 1949, the electromechanical irrigation and drainage power developed to 45600 kilowatts (including 42300 kilowatts of diesel engines), and the irrigation and drainage area was 2.27 million mu (including 2.11 million mu of mechanical irrigation and drainage area).Around Taihu Lake, Yangcheng Lake and Dianshan Lake, 400000 mu of land is irrigated by electricity and windmills, and the rest is irrigated by human and animal powered water tankers.
Although Taihu Lake Basin has abundant water resourcesrainfallFew, the tide can not be drawn in, the lake water can not be stored, the water shortage is very serious, and there are many records of serious drought in ancient times.In the 10th year of Xining in the Song Dynasty (1074), the Taihu Lake dried up and the ancient tomb market was seen in the center of the lake.In the 16th year of Wanli (1588) of the Ming Dynasty, Taihu Lake was the land, Maohu Lake, Gehu Lake and the canal were all dried up, and the river was cut off.During the 11th to 17th years of Chongzhen's reign (1638-1644), there was a continuous severe drought. The locusts ate grain, and many people died of disease. People ate each other.In the 23rd year of the Republic of China (1934), the water level of Wujiang River was only 1.87 meters, and that of Yixing was only 1.46 meters.The drought in Wujin, Jiangyin, Changshu, Taicang, Kunshan, Songjiang and other 11 counties has resulted in shallow dry water, serious pollution, unclean drinking water and inedibility.Malaria, dysentery, cholera and other epidemics occurred everywhere.
In the early days of the founding of the People's Republic of China, dredged small harbors and internal rivers, built tidal storage dams, built additional wooden culverts, improved the capacity of tidal water generation and tidal water storage, merged vehicles in succession, expanded irrigation by machinery and ships, and started to set up fixed electromechanical irrigation stations.In 1952, the Danyang Erling electric power irrigation project was started, and eight electric irrigation stations were built. The project was completed in 1953, with 115000 mu of irrigated fields.In 1955, Jintan Huangli Mechanical Irrigation Station was built, which irrigated 66000 mu of farmland, Changshu Jinjia Dawu Mechanical Irrigation and Drainage Project benefited 19000 mu, Wujiang Pingbei Station 13000 mu, Kunshan Zhoushu Station 11000 mu.Later, Hudong electric irrigation area was built in Wuxian County and Wujiang, benefiting 108000 mu.By 1956, the electromechanical irrigation power in Taihu Lake area had reached 80000 kilowatts.
While piloting the electromechanical water lifting irrigation project, gradually expand the river diversion capacityIrrigation water source。In 1952, Qipu Sluice was built in Qipu Pond.In 1953, a moderate drought hit the Taihu Lake area, 3.2 million mu. Since then, Jiuqu River, Desheng Port, Baiqu Port and other riverside diversion channels have been dredged.In 1956, the Xicheng Canal was expanded and dredged along the whole line, and the lower section of Qiputang was excavated.In 1958, Wangyu River, Zhangjiagang, Liuhe, Yanglintang, Changhu River and Xinmeng River were excavated.The next year, the Changzhen section of the Jiangnan Canal and the Jiuqu River were expanded.Zhangjiagang Gate, Liuhe Gate, Jianbi Gate, Wangyu Gate, Yanglin Gate, Hupu Gate and Jiuqu River Gate have been successively built.The preliminary completion of the backbone water diversion project along the river not only improves the irrigation conditions in the areas along the river, but also can replenish water to Taihu Lake in dry years.Due to the severe drought from 1958 to 1959, the rivers along the river brought into play the benefit of water diversion. The Liuhe River, Wangyu River and Zhangjiagang River alone diverted nearly 500 million cubic meters of water in August 1959.Through all efforts to organize the drought relief, the drought in the east of the lake has been alleviated, but the drought in the west of the lake is serious, and the water level in the lower dam of the Xuxi River has dropped to 2.5 meters.In June 1958, the provincial drought relief conference agreed to open Xuxi River Dongba to divert water from Gucheng Lake to fight drought.In July, Zhenjiang mobilized 8000 people to break the dam. In August, it began to divert water of 12 cubic meters per second.After the opening of Dongba, the original standard of lowering the dam is low, which cannot prevent flood in flood season.In April 1959, it was decided to build a dam 3.6 km below the Dongba to block the flood, and at the same time, to build a Maodong intake gate to divert water for irrigation of 200000 mu of high sounding farmland in Gaochun and Liyang.In the 1960s, the river channels along the river continued to be combined with ports to build sluice gates. In Suzhou, 34 sluice gates were combined with 52 river channels, with a total width of 429.4 meters and an average daily water diversion capacity of 40 cubic meters per second.
In the irrigation season of 1971, the rainfall in 90 days was only 172mm. On July 8, the flow of the Yangtze River Datong was only 22000 cubic meters per second. On August 3, the tide level of Zhenjiang was only 3.15 meters.The drought was alleviated in the eastern part of the lake due to great efforts in water diversion.The water diversion capacity of Huxi area is insufficient,drought severitySerious. Although 1.05 billion cubic meters of river water was introduced into the riverway along the river, and temporary stations were set up in Dantu and other places to draw river water, the water level of Taoge Lake still dropped to 2.5 meters, the water level of Nanhe River in the south fell to 1.88 meters, and the farmland was affected by drought, resulting in 540000 mu.After 1971, Huxi region continued to expand irrigation water sources, and Hudong region turned to improve internal irrigation conditions.
Taihu
In the late 1960s, Suzhou developed the "double three system" (double cropping rice triple cropping system), which brought about a new situation of concentrated peak irrigation and increased water consumptionirrigated areaLarge area, long channel and untimely water delivery can not meet the irrigation needs.In 1973, Suzhou Water Conservancy Bureau conducted a pilot project in Kunshan County and summarized the scale of the double three system rice irrigation area. Generally, it is appropriate to irrigate about 1000 mu of farmland, one brigade (village), a channel about 1000 meters long, and the field within one hour.Since then, the irrigation areas with large area, improper station location and untimely water use have been adjusted throughout the region.By 1979, the electromechanical irrigation areas in Suzhou had been adjusted to 3455 with an area of 5.24 million mu, of which the irrigation areas with an area of more than 2000 mu had decreased from 39.1% to 3.4%, the irrigation areas with an area of 500-2000 mu had increased from 57.4% to 65.7%, and the irrigation areas with an area of less than 500 mu had increased from 3.5% to 31.9%.
After 1972, the Huxi area was expandedJiuqu River、Desheng RiverAnd Zhenwu Section of Jiangnan Canal, expand Jiuqu River Gate, and rebuild Xicheng Canal Dingbo Gate (industrial and agricultural gate). The water diversion capacity can be expanded to 1.74 billion cubic meters in case of 1971 tide level.In 1973, the water conservancy planning of the Huxi area was started. The irrigation area is divided into 360000 mu reservoir Tangba irrigation area, 200000 mu Dongba diversion irrigation area, 280000 mu riverside irrigation area, 510000 mu lakeside irrigation area, and 5.4 million mu internal river diversion irrigation area.It is planned to control the irrigation water level of the river diversion irrigation area at 2.8-3.3 meters, expand the water diversion capacity of the riverside rivers, and use the pumping station to lift water at low tide by 300 cubic meters per second.In 1975, Jianbi Pumping Station was started. Six sets of axial flow pumps with a diameter of 2.8 meters were installed, and the design flow was 100 cubic meters per second, including 120 cubic meters per second for standby machines, which could supply 2.8 million mu of farmland irrigation water.
In 1978, the Taihu Lake Basin became extremely largedroughtFrom May to September, the rainfall was 314 mm, 32 mm less than the drought in 1934. The summer drought followed the autumn drought for 70 days. The water level of rivers and lakes generally declined, and the reservoirs and dams in mountain areas dried up. All regions gave full play to the role of rivers and channels to divert water from the river to fight drought.Nine key sluices (including industrial and agricultural sluices and Shiyiwei sluices) along the Yangtze River in the eastern region of the lake introduced 3.2 billion cubic meters of river water from May to September, and other culverts along the river introduced 2.4 billion cubic meters, a total of 5.6 billion cubic meters, which not only basically meets the regional agricultural water, but also supplies 640 million cubic meters of water to Taihu Lake.The tide level of Jianbi Hydrological Station in Huxi area once dropped to 2.99 meters, and the river water could not be diverted. The Jianbi Pumping Station, which had just been put into operation, operated for three months from July 1 to September 28, and pumped 640 million cubic meters of river water.However, the Huxi area is still short of 1.3 billion cubic meters of water and 1.03 million mu of drought.
In the 1970s, electromechanical power irrigation developed rapidly. By 1980, there were 19000 fixed irrigation and drainage stations, 505000 kilowatts, and 9.66 million mu of irrigation and drainage area.With the implementation of the rural contract responsibility system, the situation of farmland irrigation water has changed.Suzhou has further adjusted the irrigation areas with an area of more than 1500 mu. The irrigation areas with relatively flat land are still controlled at about 1000 mu. The rice cotton rotation and semi high field areas with complex terrain are generally controlled at about 500 mu. By 1982, the number of fixed irrigation areas had increased to 5369, including 94 areas with an area of more than 2000 mu, 967 areas with an area of 1000~2000 mu, 1566 areas with an area of 500~1000 mu, and 2742 areas with an area of less than 500 mu.In 1983, the electromechanical power of Taihu irrigation area increased to 794000 kilowatts, and the irrigated area was 9.39 million mu.
In 1980, the Ministry of Water and ElectricityYangtze River Basin Planning OfficeThe Comprehensive Planning Report of Taihu Lake Basin was put forward, and it was believed that 10.53 million mu of cultivated land in the whole basin was lack of irrigation water, including 5.17 million mu of farmland (4.14 million mu of paddy fields) in five irrigation areas in Jiangsu, including Huxi River Diversion, Chengxi Canal, Wangyu River, Huxi Lake, and Dianmao Lake, except for the lakeside areas in western Zhejiang and Hangjia Lake areas.The water supply project takes 1971 as the typical design year (guarantee rate of 94%) and needs 3.47 billion cubic meters of water;Taking 1978 as the typical year for verification (the guarantee rate is about 98.3%), 80% water supply is required, and 5.9 billion cubic meters of water needs to be supplemented.From the Huxi River Diversion System, the Xicheng Canal River Diversion System, and the Wangyu River River Diversion System, the water from the Yangtze River will be diverted to irrigate and enter the Taihu Lake to supply water to other irrigation areas;330m3/s pumping station is required in Huxi area (except Jianbi station, 60m3/s pumping station is required in Jiuqu River, Xiaohe River and Desheng River respectively), 100m3/s pumping station is required in Wangyu River, and shad harbor gate is required in Chengxi Canal.In 1987, the Provincial Water Resources Survey and Design Institute put forward the "Opinions on Regional Flood Control and Waterlogging Irrigation Planning in the Changjiang River Basin of Jiangsu Province (First Draft)", which believed that the current situation of water shortage in 1978 was 2.9 billion cubic meters. Huxi District needs to draw 330 cubic meters of river water per second (half of Xingou River, shad Port or Baiqu Port) in combination with the drainage stations along the river, and build control lines to use Taoge Lake for water storage.Hudong District makes full use of the river channel along the river to draw water from the outside, and needs to draw 120 cubic meters of river water per second in combination with the proposed drainage station in Yangcheng District.[12]
Water storage project
Qingshan Reservoir: Located 33 kilometers west of Hangzhou and upstream of Dongtiaoxi, it has a catchment area of 603 km2. It was started in 1958 and completed in April 1964.The hydroproject includes: expanding the clay core sand shell dam, with the maximum dam height of 24.1 m, dam crest elevation of 38.1 m, main dam length of 579 m, one auxiliary dam, with the height of 8.8 m and length of 71.6 m, one spillway structure, with the bottom elevation of 25 m, a total of five holes, each with a net width of 7.7 m, five radial steel gates of 5-7.7 × 5.8 m, and a maximum discharge of 2230 seconds cubic meters;The bottom elevation of the water conveyance and flood discharge tunnel is 16.5m, the diameter is 4m, and the installed capacity of the hydropower station is 4 × 500kW.The reservoir is mainly used for flood control and combined with irrigation for power generation.It was originally designed as a flood with a return period of 100 years.
Duihe Reservoir: Duihe Reservoir is located on Yuying River in Deqing County, with a catchment area of 164.7 km2.Construction started in July 1958.It was completed in August 1965.The original design dam height is 42.1m, and the total storage capacity is 190 million cubic meters. In 1961, the dam height was reduced to 33m, and the total storage capacity was 116 million cubic meters.
Wuxi Yuantouzhu
Laoshikan Reservoir: Laoshikan Reservoir is located in Xitiaoxi, Anji County, with a catchment area of 272km2.It was started in August 1958 and completed in March 1970.
Fushi Reservoir: It is located in Xitiaoxi, Anji County, with a catchment area of 328 km2.It was started in October 1972 and completed in March 1977.
Shahe Reservoir: It is located in the hilly and mountainous area in the south of Liyang County, with a catchment area of 148.5 km2.It was started in 1958 and completed in 1961.
Daxi Reservoir: It is located in the upper reaches of Daxi River in the south of Liyang County, with a catchment area of 90 km2.The construction began in November 1958, and the water conveyance culverts of the main and auxiliary dams were completed in June 1960. The dam is a homogeneous earth dam with an elevation of 17.0m.
Hengshan Reservoir: It is located in Taihua Mountain Area of Yixing County, upstream of Wuxi River, with a catchment area of 154.8 km2.The construction of the reservoir is divided into two phases: the first phase, from 1958 to 1960, the foundation clearing, anti-seepage cutoff wall and water conveyance tunnel were initially completed, and a small amount of earth was made for the dam, which was not closed.The second phase was continued in 1966 and completed as planned in 1969.The hydroproject includes: one main dam, 840m long dam crest, two auxiliary dams, 3250m long dam crest, and homogeneous earth dam;One spillway gate with a design maximum flow of 448 m3/s;The west bank has an extraordinary spillway with a width of 460m, two water conveyance culverts, and a total design flow of 10.2 m3/s;Two hydropower stations will be built out of the culvert, with 5 installed units and a capacity of 500 kW.
Hexi Reservoir: The project was approved by the National Development and Reform Commission in June 2005.The dam site is located on Hexi Stream in Changxing County, downstream of Zhudaogang Hydrological Station, 12km away from Changxing County, with a rainwater collection area of 235km2. Its main functions include flood control, water supply, tourism development and water environment improvement, with a total storage capacity of 111 million cubic meters.The reservoir complex is composed of barrage, spillway, water supply structure and emptying tunnel.The total investment of the project is 903.61 million yuan.[13]
River regulation
Wangyu River Project: including river dredging with a total length of 60.8km, building embankments and revetments on both banks, Wangting Water Conservancy Complex and Changshu Water Conservancy Complex, supporting buildings on both banks, affecting project treatment and project management facilities, with a total investment of 1.292 billion yuan.
Taipu River Project: starts from Shijia Port near Taihu Lake in Jiangsu Province in the west, ends at Nandagang in Shanghai City in the east, connects Ximao River and flows into Huangpu River, runs through Jiangsu, Zhejiang and Shanghai provinces and one city, with a total length of 57.6km.The project mainly includes: river dredging, embankment and revetment works;Taipu sluice reinforcement project (29 holes in total, each with a net width of 4m);Taipu River Pump Station Project (installed capacity of 300 cubic meters per second) and supporting building project.The total investment is 1.597 billion yuan.The project was commenced in November 1991 and completed in December 2005.In April 2006, the Ministry of Water Resources, Jiangsu Province, Zhejiang Province andShanghai Municipal People's GovernmentPreside over the completion acceptance.
Follow up project of Hangzhou Jiaxing Hunan Drainage: it is the backbone river channel for drainage from Hangzhou Jiaxing Lake area of Taihu Basin to Hangzhou Bay.Expand and dredge four longitudinal backbone rivers connecting Hangzhou Jiaxing Lake area and Hangzhou Bay, build supporting export hub projects, improve drainage conditions in Hangzhou Jiaxing Lake area, and make flood passage for Taipu River to carry Taihu Lake flood.
Great levee project around the lake: including heightening and strengthening the Great levee of Taihu Lake 255km, including 190km in Jiangsu and 65km in Zhejiang;The side protection of Taihu Lake on the causeway is 205km, including 139km of Jiangsu section and 65km of Zhejiang section;141 new and reinforced door control buildings, including 100 in Jiangsu and 41 in Zhejiang;138 km of flood prevention road pavement was paved on the top of the embankment, including 90 km of Jiangsu section and 48 km of Zhejiang section.
East and west Tiaoxi flood control project: it is the backbone river channel of mountain area in western Zhejiang that drains water to Taihu Lake, and the western flood control barrier of Hangjiahu Plain in the east.Through projects such as dredging the east and west Tiaoxi river channels, strengthening and building the west dangerous pond, the flood in the mountainous area of western Zhejiang will be guided into Taihu Lake to protectHangjiahuFlood control safety in the eastern plain.
Hangjia Hubei Drainage Channel Project: it starts from Baimi Pond in the west, ends at Wangjiangjing Luxu line in the east, borders Taihu Lake and Taipu River in the north, and ends at Lanxi Pond and Maxi in the south, covering an area of about 700 square kilometers.The administrative jurisdiction is respectively under Suzhou City, Jiangsu Province and Huzhou, Zhejiang ProvinceJiaxing City。The area is densely covered with lakes, and the ground elevation is only 3.0-3.5m, which is lower than the water level of the outer river in the flood season.
Flood control works for Minhang Sanjiandu section of the main stream of Huangpu River: improve the flood control capacity of this section and protect the flood control safety along the line by building flood control walls on both banks and control structures for branch river gates.
Hongqitang Project: Jiabei District andShanghaiQingpu, Songjiang andJinshan DistrictThe total investment in China is 975 million yuan.The Hongqitang project is classified as Grade II, the main river embankment and revetment are designed as Grade 3, and the branch river embankment and sluice are designed as Grade 4.The highway bridge is designed as a Class III highway bridge, the tractor bridge is designed as a Class IV highway bridge, the navigation of the bridge across the main river is designed as a Class IV waterway standard, and the other bridges are designed as a substandard waterway standard.
Expansion of road blocking port, dredging of Maohe River and inclined pond project: located in Qingpu District, where Suzhou and Shanghai meet, with a total investment of 723 million yuan.The project is a Grade II project, the Yuandang diversion sluice is a Grade 2 building, the main river embankment, revetment and Qingshuigang pump gate are Grade 3 buildings, and the buildings of each branch river are Grade 4 buildings;Yuandang Highway Bridge is designed as Class I highway bridge, and the bridge crossing the road block and the flood prevention road is designed as Class IV highway bridge;Flood control roads are substandard roads (refer to the standards above Class IV roads);The waterway of the road block is classified as Grade IV.[13]
flood control works
Taihu Lake Water NetworkpolderIt is a low-lying area in the Yangtze River basin of Jiangsu Province, with a total area of 11307 square kilometers (including 5183 square kilometers of polder area), 5.61 million mu of cultivated land (including 4.65 million mu of polder area), and 2.2 million mu of waterlogging prone area.According to the characteristics and drainage outlet of this area, the polder area is divided into two parts, namely, the east lake water network polder area and the west lake polder area.
Hudong water network polder area
Located in Yangcheng and Dianmao areas at the lower reaches of Taihu Lake, Hudong Water Network Dock Area is the lowest place in Taihu Water Network Dock Area, extending west to Wangyu River, north to Yantie Pond, and east and south to Shanghai and Zhejiang.The polder area is 3483 km2, and the cultivated land is 3.45 million mu.The area is densely covered with lakes, rivers and harbors, and is a famous water network area.
Taihu
In the lower reaches of Taihu Lake, the Songjiang River (Wusong River), Dongjiang River and Loujiang River drained into the river and sea.In the Spring and Autumn Period, the State of Wu once promoted Lidu, Xupu and Huangpu.During the Qin and Han Dynasties, reclamation began, and the Three Kingdoms continued to cultivate farmland. During the Northern and Southern Dynasties, polder fields developed rapidly. In some areas, polders were built in low rural areas, which were enough to resist floods and waterlogging.After the Sui and Tang dynasties, the Dongjiang River and the Loujiang River were successively blocked, gradually forming 36 ports in the southeast and northeast respectively into the sea and into the river,flood and water-loggingThe discharge path begins to change.In the second year of Yuanhe in the Tang Dynasty (807), Yuanhetang was opened, 90 miles from Suzhou to Changshu, leading the high water to the west of the pond;In the fifth year of Yuanhe, Wujiangtang Road was built to connect with the ancient pond bank, which is conducive to land access and low field development;From the first year to the ninth year of Taihe (827-835 years), the salt dredged iron pond intercepted the high water in the northeast.After the mid Tang Dynasty, scattered reclamation fields began to develop into a large number of polder fields in Tangpu. A longitudinal pool was opened five miles and seven miles north of the Wusong River, and a transverse pool was opened seven miles and ten miles north of the Wusong River. The soil of Tangpu was built as embankment, and there were weirs and gates in every river and pond.During the Wuyue period, the system of polder fields in Tangpu was consolidated and improved, and Qingyang Port and the port of entering the river were dredged in the north of Wusong River, and the rapid water port and Xiaoguanpu were dredged in the south of the Yangtze River.In the early Northern Song Dynasty, the Wusong River began to be silted up, and the drainage in the southeast was gradually blocked. The Taihu Lake flood overflowed through the farmland in Yangcheng and Dianmao, and then flowed into the sea;In addition, a large area of wasteland reclamation and reclamation blocked the waterway, and the large dikes in Tangpu gradually divided into small dikes in the creek and the river, resulting in increasingly frequent floods.Since then, although the Wusong River has been ruled for many times, and the ports and lakes along the river have been dredged, the way out for flooding has been getting worse and worse.Northern Song DynastyIn the second year of Zhihe (1055), the water was excavated to Hetang and diverted from Yangcheng Lake to Wusong River.In the first year of Yongle in the Ming Dynasty (1403), "controlling Songsong into Liuzhou" was implemented, and Fanjiabang was opened, and Liuhe River once became a main drainage river;In less than half a century, Fan Jiabang has deepened and expanded into the Huangpu River, which has eased the flood.During the Ming and Qing dynasties, Baimao, Hupu, Qipu, Liuhe and other places were dredged into the river for many times, 36 Pu, consolidating the small polder system and excavating the river network within the polder.During the Republic of China, continue dredgingWhite root, Qipu, Liuhe and other drainage channels, Baimao sluice was built, and electromechanical drainage was introduced, but the situation of flood confluence and easy flooding in Hudong water network has not changed much.
In the early days of the founding of the People's Republic of China, efforts were concentrated on repairing and strengthening dikes.In 1949, the flood season was successively hit by the Meiyu typhoon, and the dike burst.All counties set up low field rehabilitation engineering offices to organize rush repairs.By 1951, 3115 polders had been reinforced.In 1952, the embankment tops of Kunshan, Wuxian and Changshu were increased by 0.2m respectively.The rainstorm and flood in 1954 caused a large area of broken dikes and sunken dikes, and the area without broken dikes was also seriously flooded. The area of waterlogged lakes alone was flooded by 900000 mu, exposing the weakness of small fish scale dikes in low flood control and drainage standards.After the flood season, in the process of comprehensively strengthening the dikes, we have successively carried out the pilot projects of bar dike in Shipai Township, Kunshan, Xiwan dike in Wuqiu Township, Changshu, mechanical drainage and irrigation in Jinjia Grand dike, Changshu, and electric irrigation and drainage in Tongxin dike, Wujiang Hudong and Kunshan, which have achieved good results and been popularized throughout the region.At the same time, Qipu Gate was built in 1952, and the middle and lower sections of Qipu Pond were extended for 21 kilometers in 1956.
In 1957, the planning of Taihu Lake basin was started, and the "two rivers and one line" project of building Taipu River, Wangyu River and Taihu Lake control line was proposed, and the flood and waterlogging were separately controlled and the high and low levels were separated.With the consent of the Shanghai Bureau of the Communist Party of China and the Ministry of Water and Electricity, the Wangyu River and Taipu River projects were successively started in the winter of 1958.After the Wangyu River was opened in early July 1960, it played a role in regional drainage.The Taipu River was stopped midway, and only the upper section of the Taipu River in Jiangsu was formed, dividing the Dianmao area into two parts.Yangcheng and Dianmao areas form a three way drainage pattern: to the north of Loujiang Huning Railway is Yangcheng area, and waterlogged water is directly discharged into the Yangtze River;Between the Shanghai Nanjing Railway and the Taipu River, there is a lake, which flows from many river ports to the Huangpu River;The south of Taipu is in the south of Punan. The water from Hangzhou Jiaxing Lake flows into the Huangpu River. Part of the water also flows through the Taipu River, which is not fully connected, and then flows north to the Dianmao area, where it flows into the Huangpu River.Yangcheng District covers an area of 1430 km2, 1.5 million mu of arable land, 1500 km2 of paddy land and 1.32 million mu of arable land, and Punan District covers an area of 553 km2, 460000 mu of arable land. The ground elevation is mostly 3 to 4 meters. The low-lying polder area is below 3.5 meters, and the semi high farmland polder area is above 3.5 meters.
In the project of "high standard river network" started in the winter of 1958, the whole region joined the polders and developed electromechanical drainage, and renovated Yangcheng Pianliu River, Yanglintang River, Changhu River and other main drainage rivers.According to the flood level in 1954, the typhoon in 1956 was not determined, and the rain pattern in 1957 was three daysrainfallThe standard of no waterlogging can be discharged one day after 200 mm rain, the dyke shall be combined, the dyke shall be heightened, and the electromechanical irrigation and drainage station shall be built.By 1962, 281 joint dikes with an area of more than 1000 mu had been initially built, including 56 large dikes with an area of more than 10000 mu, 83 large dikes with an area of more than 5000 mu to 10000 mu, 142 large dikes with an area of more than 1000 mu to 5000 mu, and 1.76 million mu of cultivated land within the dikes, with an average of 6263 mu of cultivated land per dike.In 1958, the electromechanical drainage and irrigation project in the polder area focused on Kunshan Kunbei, Wuxian Weitang, Changshu Renyang and Xinzhuang, Taicang Baliqiao, Wujiang Bage and Zhenze, adding 9700 kilowatts and benefiting 94000 mu.In 1959, Changshu Mocheng and Ouqu, Kunshan and Kunzhong, Wuxian Baoan and Wangting, Wujiang Punan, etc., were the focus, with an additional 8100 kilowatts and 48000 mu of benefits.In 1960, with Kunshan Kunnan, Wujiang Tongluo and Qingyun, Taicang Shuangfeng and Xinmao as the focus, 3600 kilowatts were added, benefiting 330000 mu.By 1962, the area of electric power irrigation and drainage had reached 1.17 million mu, accounting for 66% of the farmland in the dikes. The drainage in the dikes had developed from "three vehicles" to electromechanical drainage, greatly enhancing the drainage capacity.
Due to the rapid development of the dyke, the complex terrain and the large area of the dyke, new internal and external drainage contradictions have emerged.In 1961, through consultation between Jiangsu and Zhejiang provinces, 9 polders in the south of Punan were adjusted to 22 polders, and 13 inland rivers were given up for drainage of external rivers. In 1965, another 5 polders were divided.Since then, Changshu County has split five major dikes, Kunshan County has adjusted five major dikes to give up nine drainage channels, and Wu County has adjusted six drainage channels in combination with the adjustment of the dikes to improve the external drainage conditions.By 1972, there were 404 associated polders with an area of more than 1000 mu, including 30 large polders with an area of more than 10000 mu, 104 large polders with an area of more than 5000 mu to 10000 mu, 270 large polders with an area of more than 1000 mu to 5000 mu, and 1.84 million mu of cultivated land within the polders, with an average of each polderCultivated land4554 mu.
After 1970, we continued to build the Taihu Lake levee, continue to renovate the drainage trunk river, build semi high field dikes, and adjust and improve electromechanical irrigation and drainage.After the implementation of the Qingsong encircling project in Shanghai, 23 of the 43 river channels flowing eastward into the Huangpu River were blocked, and the downstream conditions of Dianshan Lake worsened.In 1977, Jiangsu and Shanghai agreed to expand road blocking ports, but failed to implement them.During this period, Zeng mechanically dredged 9 kilometers of Jishui Port to improve the ability of waterlogged water in the middle of Dianmao area to drain to Dianshan Lake;The Xinta section of Badang River was excavated, so that the waterlogged water in the south of Dianmao section drained directly eastward to the Dianshan Lake in Yuandang;Comprehensively expand the Loujiang River and Liuhe River Phase II Project, dredge the middle and lower sections of Baimao Pond, excavate the west section of Yanglin Pond and two narrow sections of Shipai Town in Kunshan and Renyang Town in Changshu upstream of Qipu Pond, and improve the drainage capacity of Yangcheng District into the river.In 1979, Kunshan put forward the plan of building Qiandong and Qianxi Great Docks.In 1983, the Qiandong Great Docking Project was started, which combined the 24 half high field small docks south of Wusong River and east of Qiandengpu and part of the farmland outside the docks into a large one that can be divided and combined, and enhanced the ability of grading pre lowering and zoning waterlogging drainage.In the winter of 1986, the Qianxi Union Dock Project was started again.By 1987, the Hudong water network polder area had undergone comprehensive treatment, with 610 polders and 2.29 million mu of arable land, including 326 low-lying field polders and 1.27 million mu, and 284 semi high field polders and 1.02 million mu. Electromechanical irrigation and drainage have been widely popularized.The drainage capacity of Yangcheng Tablet has been greatly improved, but it has not yet reached the design standard for rainfall pattern in 1962.Dianmao and Punan have not yet got rid of the situation of indiscriminate flood and waterlogging, and drainage is difficult.
Huxi polder area
The Huxi polder area is located between the hilly area and the plain area in the Huxi area at the upstream of Taihu Lake, with an area of 1700km2, 1.2 million mu of arable land, and a ground elevation of about 4.0 meters.The distribution of polder areas is on the west bank of Tongji River and the south section of Danjin Licao River in the west, on the Nanhe River and Zhonghe River in the south, and around Taihu Lake in the east.The drainage outlets in polder areas were historically limited by plain areas and drained eastward into Taihu Lake.The main drainage channels in the polder area are Tongji River and Danjin Licao River in the west;The south is Nanhe River and Zhonghe River;In the east are Caoqiao River, Yincun Port, Wujin Port, Shun River, etc.During the Song and Ming Dynasties, the Danjin Li Caohe River, Wujin Port, Caoqiao River and Shun River were partially dredged.During the Republic of China, Nanhe River, Danjin Licao River, Caoqiao River and Tongji River were partially dredged.In the 29th year of the Republic of China (1940), Jiangyin, Wujin and Wuxi Border Region Anti enemy Committees mobilized people along the river to dredge the Shun River.These rivers discharge both waterlogged water and flood water, with a low standard, less than once every three years.
Taihu
After the founding of the People's Republic of China, Huxi polder area renovated dikes, joined dikes and merged dikes, developed electromechanical irrigation and drainage, built irrigation and water conservancy, dredged drainage trunk rivers, built gates along rivers, and constantly improved the ability of drainage.In 1975, after the completion of the Water Conservancy Planning for the West Area of Taihu Lake in Jiangsu Province, the drainage trunk river was further dredged according to the planning requirements, and in 1978, Jianbi was built near the river with a pumping capacity of 120 cubic meters per secondPumping station, reducing the pressure of drainage from the northern plain to the polder area.
The regulation of the main drainage rivers in this area is as follows: Nanhe Nanxi River, 87.5km long, starts at the junction of Chunli, crosses Liyang, and enters Taihu Lake at Dapu, Yixing City.In the winter of 1951, the Yixing moat was dredged; in 1965 and 1966, the east section of the Nanhe River (the section from Nanduqiao to the junction of Yili) was dredged; in 1969, the west section of the Nanhe River (the section from the river to Nandu) was dredged; in 1973, the section from Xiaba to the river was dredged; in 1974, the section from Dongdang to Taihu was dredged.Zhonghe Beixi River starts from the water diversion of Laowuzui South River, Qingfeng Township, Liyang County, in the west, and ends at Xipeng in Yixing in the east, with a total length of 45.5km. In 1976, it expanded the territory of Liyang (from Laowuzui to Yangxiang Bridge) for 29km.The Licao River in Danjin starts from the Qili Bridge on the Jiangnan Canal in the north, passes through Danyang and Jintan, and reaches the urban area of Liyang City in the south, connecting with the South River, with a total length of 66.9 kilometers.The reach from Danyang to Jintan was dredged five times in 1954, 1958, 1959, 1969 and 1971, and the reach from Jintan to Liyang was dredged three times in 1966, 1977 and 1981. In 1970, a Danjin River sluice was built at the junction of Danyang and Jintan counties.Tongji River,upper reachesFrom Lunshan Reservoir in Jurong County to Baonian SectionXihe River, 33 km long;The downstream enters the polder area and reaches the Danjin Licao River from Baonian through Zhixi Town, with a length of 36 kilometers. After the founding of the People's Republic of China, dredging will be carried out by stages.Danyang and Dantu County expanded Baonian Sancha River in 1964, 1969 and 1971.In 1958, 1966, 1972, 1973 and 1976, Jintan County expanded the Sancha River to Licao River in Danjin in five stages.Wujin Port (formerly known as Qishu Port), located in the southeast of Wujin, is 29 kilometers long, starting from the Jiangnan Canal in the north and entering Taihu Lake from Butterfly Bang in the south.In 1974, 1977 and 1978, the whole line was dredged three times.Caoqiao River, located between Taihu Lake and Gehu Lake, starts from Baidu of Taihu Lake in the east and passes through Caoqiao, Mazhuang and Jiantou to Gehu Lake, with a length of 22.3km. The whole line was dredged in 1966.Yincun Port (also known as Taige South Canal) starts from Gehu Shadu Port in the west and passes throughHeqiao TownAfter Chenqiao, it enters Taihu Lake, with a length of 23 kilometers. In 1975, the whole line was expanded and dredged.The drainage capacity of the above drainage trunk rivers has been greatly improved after several treatments, but the Huxi polder area is still unable to fully resist the 10-year flood.[14]
socioeconomic
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Resources
Taihu
According to《Ichthyology of Taihu Lake》It is recorded that there are 107 species of fish, belonging to 14 orders, 25 families and 74 genera. Their ecological types mainly include three types: the first is the sedentary fish in Taihu Lake, such as carp, crucian carp, bream, bream, albacorn, coilia andWhitebaitEtc;The second is river sea migratory fish, such asEel、a shadandFugu orientalisEtc;The third is the migratory fish in the Jianghu, such as grass, green, silver carp and bighead carp.Due to the change of the natural environment and the interference of human economic activities, especially the construction of a large number of gates and dams along the river and lake in the 1950s and 1960s, the "reclamation of land from lakes" in the 1960s and 1970s, and the use of destructive fishing gear and fishing methods, the number of migratory and semi migratory fish and the resident fish resources along the coastal zone for spawning decreased,However, the number of open water young fish species in the lake has gradually increased under the artificial breeding protection measures, forming a pattern of Taihu Lake fish resources with coilia, whitebait, etc. as the main body and a large annual variation.At present, there are more than 20 kinds of economic fish resources in Taihu Lake, including Coilia mystus, whitebait, albacorn, carp, crucian carp, bream bream, grass carp, black carp, silver carp, bighead carp, eel, flower fish bone, catfish, mandarin fish, snakehead fish, river fish and bream like fish.[6]
Taihu whitebait: tender meat, rich nutrition, no scales, no thorns, no fishy smell, can cook various dishes.The Japanese often associate whitebait withHerring seed、Sea urchin sauceTogether, seasonings are added to make precious dishes.Dry the whitebait, and its color, fragrance, taste and shape will remain unchanged for a long time.Before cooking, soak it in water. It is as soft as boneless and can be made into various kinds of famous dishes.[15]
Taihu white fish: also known as "minnows", it is one of the carnivorous economic fishes, with a long, narrow and flat body, thin bones and scales, and silvery light.It has not been farmed yet and mainly relies on natural fishing.The white fish is tender and has much fat under the scales, which is similar to shad.[16]
Taihu white shrimp: White shrimp has thin shell, tender meat and delicious taste.The meat yield of white shrimp shelled is high. It can also be processed into dried shrimp. After peeling, it is called "Hukai".Shrimp can also be used as medicine.For internal useToriThe function of detoxification.[17]
Taihu Pearl
TaihuPearl, also known as Taihu Lake Pearl.It is classified into nine categories by originPearlOne of the varieties.
Taihu Crab
Taihu pearls are both precious decorations and precious medicinal materials.Pearl is heat clearing and detoxification, cold in nature, sweet in taste, and yang concealing. It can calm the mind, relieve cough and phlegm, improve eyesight and pain, astringe muscles, treat hypertension, elderly bronchitis, and gastric ulcer. It is Pearl Powder, Liushen PillChildren Rejuvenation PillIt is one of the important ingredients of more than 20 kinds of Chinese patent medicines.Pearl products are still improvingPhysical functionPromote metabolism, strengthen physique, delay aging and other functions.[18]
Taihu Crab
Taihu Lake Crab, also known as Taihu Lake Crab, grows in Taihu Lake watersCrabIts back shell is firm and concave like a tiger. Its belly is blue and white. There is an umbilical cord under its belly. The male is sharp and the female is clustered. There is hard hair inside.Crabs are migratory creatures. Every autumn and winter, when the gonads of the second instar crabs are mature, they flock to the eastRivers and seasIn the shallow sea at the intersection, it breeds and then lives.In the early summer of the next year, the hatching crabs went upstream and returned to Taihu Lake. After many times of molting, they gradually grew up and became big crabs the next year.[18]
Cultural legends
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It is said that more than 4000 years ago, the founder of water control in ChinaXia YuFengshun EmperorYao ChonghuaHe ordered us to control the flood in Taihu Lake and dug three main waterways,Dongjiang、Loujiang、Wusong River, connecting Taihu Lake and the sea, and channeling the flood into the sea.This is Sima Qian《Redords of the Grand History of China》According to the record in, "Yu controlled the flood in Wu and connected the canals to three rivers and five lakes." Taihu Lake is vast, 200 miles from east to west, 120 miles from north to south, covering an area of 36000 hectares.
Evening at Taihu Lake
It is said that one day a long time ago, the Queen Mother was going to celebrate her birthday,Jade EmperorAsk the four King Kong to carry a generous gift.The Queen Mother was so happy that she couldn't even close her mouth when she saw it.It turned out that what the Jade Emperor sent was a large silver basin, with 72 extra large jades in it, as well as birds and animals carved with various colorful jades, which was a treasure basin;Seen from afar, it still looks like a large exquisite bonsai. All the immortals praise it.As we all know from Journey to the West, the Queen Mother held a peach partyBi MawenAs a result, Monkey King, the Great Sage of Heaven, lost his temper and caused havoc in Heaven.When he saw the big silver basin sent by the Jade Emperor, he hit it with a stick. The silver basin fell from the sky, fell to the ground and hit a big hole. The silver turned into white water and formed a lake of 36000 hectares. Therefore, the lake fell from the sky. The horizontal line above the word "heaven" fell below is a point, that is, "too"So this lake is called "Taihu Lake".72 jadeite jades become 72 peaks, which are distributed in the middle of Taihu Lake.The fish carved with jade is the silverfish with white flesh, tender meat and delicious taste in Taihu Lake.jadeThe carved birds become pairs of mandarin ducks.Only animals did not survive.
According to scientific research, the real appearance of Taihu Lake isHaiji Lake, geographically called“lagoon”。It used to be a big bay. Due to the sedimentation of the Yangtze River and the Qiantang River, the Yangtze River Delta continued to extend eastward. The bay was closed by sand bars formed by sediment deposition, forming Taihu Lakeriver waterWith the effect of rainwater, seawater is desalinated year by year, so it becomes a freshwater lake.Therefore, some people say that he is the "son of the sea".
There is also a historical story.According to historical records, at the end of the Spring and Autumn Period, King Fuchai of Wu defeated King Goujian of Yue. King Yue was trapped in Kuaiji by the King of Wu, and was captured to Gusu to serve Fuchai.Later, Fan Li offered a plan to dedicate Xi Shi, a folk beauty, to Fu Chai, the king of Wu, so that he could sing and dance in the morning, indulge in wine and sex, and lose his fighting spirit. Finally, he made the king of Yue revenge and defeated the State of Wu at one stroke.Fan Li was awarded the title of the Supreme General for his contribution to "pacifying Wu and conquering the country".However, Fan Li knew that it was a historical rule in feudal society that all birds had to hide their bows, and all rabbits had to die and dogs had to cook.Gou Jian is a man who can share weal and woe with him, but can't share happiness with him. He has a high reputation and won great achievements. If he doesn't retreat bravely, he may not die well.After returning from the Central Plains,Fan LiThen he said to Gou Jian, "The king should work hard! Please allow me to resign and never enter the country of Yue again." Gou Jian was surprised, "Why are you leaving me now?" Fan Li said, "I heard that as a minister, you worry about your servants' work and insult them to death. In the past, the king was humiliated in Kuaiji, but I didn't die to help the king achieve hegemony. NowkingMy career has been accomplished, and I should accept the punishment of being humiliated in Kuaiji. "[23]So Fan Li quietly left Yue.It was seen that Fan Li took Xi Shi with him and drove a boat out of the three rivers and across the five lakes, without knowing where he was going.Later, he ran an industry and became a millionaire with a huge amount of money. He was known as Duke Tao Zhu and died.Politicians and writers of all dynasties expressed deep feelings about Fan Li's successful retirement and good results. Wang Zun, a poet of the late Tang Dynasty, wrote the poem "Five Lakes" and praised Fan Li's foresight: "We have established the power to conquer Wu, and set sail to promote the wind of the five lakes. I don't know who is honored as an official in the Warring States Period, but who is like Tao Zhu?"
comprehensive control
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In 2022, six departments, including the National Development and Reform Commission and the Ministry of Natural Resources, issued a new round of Overall Plan for Comprehensive Treatment of Water Environment in the Taihu Lake Basin[22]。
Related events
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The heart shaped island in Suzhou Bay of Taihu Lake is located in the happy village of Taihu Lake. In May 2022, Gaofen satellite found this paradise like love island.[19]
