abstract
The longest river and the most important waterway in Britain is the mother river of Britain. It originated in the Cotswolds in southwest England, and many streams in England gathered along the way. The river flows into downtown London from the west, and the lower reaches of London widen to form a 29-kilometer-wide estuary, and finally flows into the North Sea through Noel Island. It is 259 kilometers from the source to London Bridge and 77 kilometers from London Bridge to Noel Island, with a total length of 340 kilometers and a navigation mileage of 309 kilometers. In Celtic, Thames means "wide river". In fact, since London Bridge, the riverbed has deepened and the river surface has widened a lot. The river around London Bridge is 229 meters wide, and it is 640 meters wide when it reaches Graveson. Watershed area 1 1.400 square kilometers. The riverbed slope is slightly gentle, the water level is stable, the flow rate is large in winter, and it rarely freezes. The sailing mileage is 280 kilometers, and the intertidal zone is below London, so seagoing ships can reach London by tide (88 kilometers away from the estuary, which is one of the busiest waterways in the world). There are four car tunnels from Tower Bridge to the mouth of the London River. There are many roads and railway bridges along the river above the tower bridge, and there are canals connected with other rivers. The main source of water in London.
Compared with some big rivers on the earth, the Thames is not too long, but the place where it flows is the essence of British culture. Perhaps on the other hand, the Thames gave birth to brilliant British civilization. Most of the main buildings in London are located on both sides of the Thames, especially those with a history of hundreds or even three or four hundred years, such as Nelson statue symbolizing victory, Westminster Abbey where many great men are buried, St. Paul's Cathedral in Renaissance style, the Tower of London, Tower Bridge in London and so on. Every building is a masterpiece of art. Although these buildings have gone through vicissitudes and even experienced the baptism of war like World War II, they still maintain their inherent appearance and are still used by people today. In the upper reaches of London, there are many places of interest along the Thames, such as Eton, Oxford, Henry and Windsor. The mouth of the Thames is full of busy British merchant ships, but the upper Thames is famous for its static beauty.
The Thames, which runs through the center of London, makes London a rare port in the world. Moreover, the mouth of the Thames is far away from the Rhine estuary in continental Europe across the North Sea, opening a direct shipping channel to the most fertile areas in Europe. At the same time, London is located halfway between the Mediterranean Sea and the Baltic Sea, so it has become the most ideal commercial port in the region, which undoubtedly promoted the prosperity of London.
The Thames valley plays an important role in British history. British politician john burns once said: The Thames is the most beautiful river in the world, "because it is a flowing history."
physical geography
The Thames is the largest river in Britain, which rises in the Cotswold Mountains near Sestad, Salem, southern England. It flows from west to east, turns southeast at Oxford, northeast at Reading, east at Windsor, flows through London, and finally flows into the North Sea near Southend. The total length of the river is 338km, the basin area is1.1.40000 km2, the average annual discharge is 60.0m3/s, and the average annual runoff is1.800 million m3. Geographical location of river basin II. 08' ~ 0 east longitude. 43', latitude 5 1. 00'~52。 3'。
The Thames has a complex water network and many tributaries. The main tributaries are Chulun River, Cologne River, Cole River, Vindra River, Avonlod River, Chaver River, Ray River and Oak River.
Hydrological survey
The average annual precipitation in Thames Valley is 704 mm, and the average annual runoff is 65.438+0.89 billion cubic meters. Floods mostly occur in winter, and low water mostly occurs in summer. The maximum discharge recorded by Taidington Dam is 1050m3/s (1894) and the minimum discharge is 0.9 1m3/s (1934). The Thames is stable and generally does not freeze in winter. There are many canals connected with other rivers, and the shipping conditions are very good. The main stream is 99 kilometers long, which is the estuary section under the Tetdington Dam in west London, and seagoing vessels can ride the tide to London. The Thames has many functions, but there are water conservancy problems such as water shortage, water pollution, flood control and moisture prevention.
(1) water supply. Thames water supply system provides a stable and reliable water source for 6.5438+0.3 million people, 20 million tourists and industrial enterprises every year. There are 94 waterworks with 2.73 kilometers of water supply pipes and 2.64 million cubic meters of daily water supply. Of the total water supply, 69% is directly supplied by Thames Water Affairs Bureau, and 365,438+0% is supplied by seven statutory water supply companies. 565,438+0.3% of the total water supply comes from Thames, 8.65,438+0% from Lihe and 40.6% from groundwater.
Ensuring water supply is a major problem in the regulation and construction of Thames. In order to improve the water supply capacity, in recent years, reservoirs in hilly areas and reservoirs in plain areas have been continuously built in the basin. At present, the total storage capacity of the reservoir is 900 million m3, of which there are 1 1 reservoir in London, and the total storage capacity can be London water supply 100 day.
(2) Water pollution control. There are 476 sewage treatment plants in Thames Valley, with a daily sewage treatment capacity of 4.38 million m3 (of which about 6.5438+0 million m3 can also treat sewage entering the sewer due to rainstorm). The total length of sewer pipes in the whole basin is 4.5km, and all sewage in the Thames basin must be treated before it can be discharged into the river or injected into the ground. The prevention and control of Thames pollution has achieved remarkable results. Except for the reach affected by tidal water, the water quality of other reaches has reached the drinking water quality standard.
(3) Flood control and moisture prevention. 1875, 1877, 1894, the tide once entered London. 1928 65438+ 10, the Thames reached the highest flood level on record, and most parts of London were flooded. 1953, the extraordinary storm surge once again entered the urban area of London, causing more than 300 deaths, so it was proposed to build a tidal sluice. At the same time, improve the upstream and downstream dikes, strengthen and improve flood control organizations, and establish flood control forecasting systems.
places of historic interest and scenic beauty
Thames is the longest river in Britain. It originated in Cotswolds, England. The river flows into downtown London from the west and finally into the North Sea via Noel Island. The total length is 340 kilometers and the navigation mileage is 309 kilometers. Since London Bridge, the riverbed has deepened and the river surface has been greatly widened. The river around London Bridge is 229 meters wide, reaching 640 meters in Graveson.
Thames means "wide river" in Celtic. As a shortcut to the Atlantic Ocean, there are many places of interest along the river.
From the entrance to the upstream, the first tourist spot is Greenwich. There are lush old trees on the mountain, an ancient observatory on the top of the mountain, and towns close to mountains and rivers. It is the seat of the Royal Naval Academy.
Tower Bridge in London is the first bridge from Greenwich to Thames, and there are many docks, docks and warehouses on both sides of the river. Crossing the tower bridge and entering downtown London to the west, the scenery on both sides of the river changed suddenly, with many tall buildings and palaces. Ancient buildings such as Parliament Building, Royal Concert Hall, Tower of London, Southwark Cathedral and St Paul's Cathedral are faintly visible. The town hall in London's administrative center is near the river. There are 27 bridges along the river, with different structural styles and different scenery. Among them, Waterloo Bridge, Westminster Bridge and Lambeth Bridge are the most spectacular.
On the bank of Hebei, Victoria binjiang road is an ideal place for tourists to take a walk and rest. At night, the street lamps along the river are bright, the small lights set each other off with the water waves, and when they are broken, they get together again, making people feel the rare leisure in London. Egypt's Cleopatra obelisk, the replica of the Sphinx, the statue of camel soldiers and other cultural relics are also located on both sides of the river.
Since 1856, the rowing competitions between Oxford University and Cambridge University and the Royal Henry Cup rowing competition are held on the river every Easter.
The Thames has always been the object of poets' eulogizing and painters' sketching, and it is also the only place for tourists to visit the ancient Range Rover. Along the river from London, Eton, Oxford, Henry, Windsor, Hampton Young, Richmond and other small towns have immortal places of interest and are famous tourist attractions.
Governance situation
Thames is a famous "mother river" in Britain. Originated in Cotswolds Hills in the southwest of England, it is 402km long and crosses the British capital London and 10 cities along the river, with a drainage area of13000km2. It widens in the lower reaches of London, forming a 29-kilometer-wide estuary that flows into the North Sea. In the upper reaches of London, there are many places of interest along the Thames, such as Eton, Oxford, Henry and Windsor. The mouth of the Thames is full of busy British merchant ships, but the upper Thames is famous for its static beauty. The Thames valley plays an important role in British history. British politician john burns once said: The Thames is the most beautiful river in the world, "because it is a flowing history." After the industrial revolution, the population was concentrated, and a large number of urban domestic sewage and industrial wastewater were directly discharged into Hanoi without treatment. In addition, a lot of rubbish and dirt piled up along the coast, making this river an open sewer in London. Summer stinks, causing foreign buildings along the river and the London bell tower to close their doors and windows. Due to the pollution of drinking water in London and the fog in the early morning, it is often mixed with toxic gases such as sulfur dioxide, sulfur monoxide and nitrogen oxides emitted by industry. Finally, the cholera epidemic broke out many times, and the London fog and haze incident shocked the world. Among them, only 33,460 people died of cholera. In addition, rivers are also affected by tides, which force sewage and wastewater to flow back sharply at high tide, resulting in sewage and smelly water flowing all over the street.
The British government began to govern the river in the 1960s. First of all, it has made strict regulations on the direct discharge of industrial wastewater and domestic sewage into the Thames by legislation. The relevant authorities have also rebuilt and expanded London's sewers, built more than 450 sewage treatment plants, and formed a complete urban sewage treatment system, handling nearly 430,000 cubic meters of sewage every day. At present, the domestic sewage along the Thames must be concentrated in the sewage treatment plant before it can be discharged into the Thames after precipitation and disinfection. The sewage treatment fee is included in the residents' tap water fee. According to relevant laws, industrial wastewater must be treated by enterprises themselves, and can only be discharged into rivers after reaching a certain standard. Enterprises that are unable to treat wastewater can discharge the wastewater to the sewage department of the River Administration Bureau, but they have to pay sewage charges. Inspectors will also inspect the factory regularly and irregularly. Those factories that fail to meet wastewater discharge standards and disobey supervision will be prosecuted, fined or even closed. After nearly 20 years of hard renovation, it cost 2 billion pounds. Now, the Thames flowing through London has changed from a dead river and a stinking river to one of the cleanest urban waterways in the world, and the Thames has finally been revived. Now you can see the clear sea water in the famous Tower Bridge section in the city center, and anglers can also catch precious salmon and squat fish. According to the investigation, the number of fish in this river has recovered to 100. At the same time, due to the good water quality of the river, the Chinese soft-shelled turtle crab, which was originally abundant in China, survived and multiplied in the river, forming a dominant population. At present, a large number of aquatic products operators in London's mediocre street have purchased and listed, and their purchase price is 45% lower than that of China's air defense transportation.
The key to the success of Thames management is not to adopt the most advanced technology and technology, but to carry out bold system reform and scientific management, which is called "a major revolution in aquaculture management system" in Europe. They unified management of the river reach, divided the whole river into 10 areas, merged more than 200 water management units, and established a new water management bureau-Thames Water Management Bureau. Then, according to the nature of the business, a clear division of labor was made and strictly implemented. In water treatment technology, conventional measures are adopted, such as intercepting sewage discharge, biological oxidation, aeration and oxygenation and microbial activated sludge. The treated wastewater is used for fish farming and aquaculture. , thus bringing vitality to the water industry. Its advantages are mainly as follows:
(1) Centralized and unified management enables water resources to be reasonably and effectively protected, developed and utilized according to the laws of natural development, so as to prevent waste and destruction of water resources and improve the coefficient of water reuse. (2) It has changed the situation of mutual restraint and repeated work among all links of water management in the past, and built a unified whole of mutual cooperation. (3) A complete water conservancy system has been established, which reasonably coordinated the comprehensive utilization of water plants, sewage treatment, fish farming, irrigation, flood control and water ecological protection, and fully mobilized the enthusiasm of all departments.