After the rainstorm, see the world city sewer secret (Figure)

In foreign countries, in order to prevent the city waterlogging, drainage standards are generally higher than the domestic city,New York"Ten to fifteen years" (Note: once in a year is 36 mm of rainfall per hour) standard,Tokyo"Five to ten years", Paris is the "five years" standard.

For exampleLondonThe sewer system and Paris, has 150 years of history, but still maintained a strong drainage function. Tokyo underground drainage system and built in 2006, is a strong, more advanced, guarding Tokyo from waterlogging.

London sewer workers

London: to prevent cholera of drainage system

If the drainage system of a city is out of the question, then not only the water immersion street, flooded car problems, may also lead to the epidemic, this is the warning that the London sewerage system caused by backward.

London now use the sewer system was built in 150 years ago. 1856.BritainDesigners start underground waterway system research and design in London, while the Anglo-French allied forces in China launched the second Opium war.

Who would not think of, 150 years ago London was a garbage everywhere, smelly, a cholera epidemic in the city. In 1848 -1849 years, the number of cholera deaths in London more than 14000 people. The people most probably it did not actually happen that, like other epidemics like cholera during that period of time as one falls, also because of air pollution, and did not realize the real causes of water pollution.

In 1849, the cholera outbreak ended, the British capital of sewage management committee appointed Joseph Pasaje as the measurement engineer, to determine how the future improvement of city drainage system.

In 1856, Bazalgette suggestions will be all of the sewage directly into the Thames estuary, all into the sea, but his design for the 5 time by the veto. The summer of 1858, the most serious since the city of London smell reached the level of history, London municipal authorities are under pressure to reform plan Bazalgette's.

The London underground drainage system renovation project officially started in 1859, completed in 1865, the actual length to 2000 kilometers. Project completed that year, all the sewage is discharged into the sea in london.

Many people worry about the hollowing out of the London underground will not collapse, in order to solve this problem, the engineering department has developed a new high strength cement, 380000000 pieces of concrete brick manufacturing with this cement, to form a solid sewer.

Because the separated sewage and groundwater, London sewer reconstruction unexpectedly solves the problem of cholera in water. Since then, the London never happened cholera.