Sudden rainstorm, once again sparked concern on the issue of urban drainage systems. The Beijing urban drainage system design criteria 1-3 years only drain the rainfall of 1/5. Urban drainage system failed to play a role, has led to Beijing 25 people drowned. Such a tragedy occurs, people heart question: urban construction do not attach importance to the underground drainage system and other facilities, and accused of "face, not in the child".

Beijing hit by torrential rain, the Forbidden City did not occur in the stagnant water. Why this 600-year-drainage system construction can not currently rainstorm in 61 years not once stagnant water? Its urban drainage system and what are the characteristics of it?

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Stocks rise of urban drainage systems

21, 2009 ushered in 61 years of the maximum intensity of rainfall, triggering concerns about the municipal drainage system the affected water conservancy construction plate adverse economic gains across the board, the sector as a whole rose more than 2%.

Individual stocks, Leo shares daily limit, Dragon Pipe, New Territories Pump up more than 4%, the National Unification shares rose more than 3 percent, Yu water rose more than 1.59%.

Beijing urban drainage system standard is 1-3 years

Beijing's urban drainage system mainly consists of two major categories of stormwater drainage system, sewage drainage system. Which, rainwater drainage system consists of residential drain lines, road drainage branch trunk system, drainage channels and support the main stream system.

Wang Yi, director of the Beijing Municipal Flood Control Office has said that Beijing's drainage system design is 1-3 years, able to adapt to a 36-45 mm of rainfall per hour, only Tiananmen Square and Olympic Park near the drain line can reach five years once standard . Relative Beijing, New York, 10-15 years, Tokyo 5-10 years, Paris is the 5-year return.

In fact, this year from July 21 to 22 days before the torrential rain, the 90 sunken overpass in Beijing has been established in the drainage plan, but the city average of up to 225 millimeters of rainfall, many waterlogging is not surprising.

In addition to the design standards are not high, there is the problem of an aging drainage system in Beijing. Currently, Beijing drain line still contains the old brick built liberation ditch. In addition, some of the pumping station electrical equipment, components, general aging, greatly reduce the damage, factor of safety and reliability, sensitivity, part of the pumping station automation, explosion-proof ventilation system monitoring and control facilities have been unable to adapt to today's industry, management need.

In the prevention and treatment of urban waterlogging, has no legal basis. The experts called for the country should learn from foreign anti-urban waterlogging legal experience in legislation, as soon as possible to develop the "Urban Flood Control, around of urban waterlogging prevention, planning, and government responsibility, with a wide range of legislation.

Yesterday, the Chinese Academy of Sciences, China IWHR, director of water resources, said Wang Hao, the rapid development of urban underground space occupied continuously, it is difficult to meet the water supply and drainage system upgrade is not to say, also belong in the municipal, drainage, environmental protection, power, communications and other different departments, do not have a unified and coordinated institutions unified planning, construction, imperative that clear lines of responsibility, integration of forces, alteration of drainage network.

Beijing Water Authority has responded by saying, drainage network updates in Beijing, faces many problems. Such as the tube online have new buildings of the old town, unable to demolition, only patch, found a complementary one. At the same time, facing urban construction project approval, construction of the project can not keep up, leading to the delayed construction of the drainage system.

Drainage network event of default "Every floods must paralysis" to be changed

According to Xinhua reports, Wang Yi, chief engineer of the Beijing Municipal Flood Control and Drought Relief Headquarters Office has introduced the 2000 Beijing built area of ??just 700 square kilometers, and has reached nearly 1,400 square kilometers in 2010. Currently, only Tiananmen Square and Olympic Park near the drain line can reach 5 years of drainage standards, most of the Beijing municipal storm sewer construction in accordance with the standard 1-3 year return, which is able to adapt to the 36 millimeters per hour to 45 mm of rainfall. However, if blindly to improve construction standards, built after many pipes may be of no use, is a waste of resources.

Chinese Academy of Sciences, China IWHR, director of water resources, said Wang Hao, the rapid urban development of the underground space is occupied continuously, it is difficult to meet the water supply and drainage system upgrade does not say, also belong in the municipal, drainage, environmental protection, power, communications departments, not yet a unified and coordinated organization of unified planning, construction is imperative that clear lines of responsibility, integration of forces, alteration of drainage network.

Rainstorm brought With the storm is not gradually fade out of vision. Experts pointed out that the city is a huge system, the the disasters arrival of a test of the wisdom of the city manager. At present, China's urban public safety warning information needs for emergency response to comprehensive disaster reduction change there without specifically more without condition, to pay attention to the intrinsic quality of the city.

Experts advocate a reservoir in a row, "to solve the problem

It is reported that Hong Kong, "Wen Wei Po" 23 Nikkan said, a storm has exposed the shortcomings of the Beijing municipal construction, experts have called for the transformation of urban drainage systems has become imperative. LIU Shu-kun, water expert, pointed out that the face of the current situation of the Beijing municipal construction, a reservoir in a row "to solve problems.

LIU Shu-kun pointed out that the face of the current situation of the Beijing municipal construction, a reservoir in a row "to solve problems, that savings stagnant water and re-use as a resource, in addition to surface water storage, but also to build underground reservoirs and underground river to reserve As for drainage, unnecessary water; since last year after a storm, the relevant departments to begin preparations for the planning of the drainage system, and to improve the city roads and river drainage capacity. In fact, Beijing is a city of more "dry". LIU Shu-kun stressed that the Government needs to do most is truly relevant measures put in place.

Extended reading
Forbidden City why not water?

Legal Evening News reported on July 21, Beijing heavy rain, the National Palace does not appear stagnant water. Why this 600-year system building can not now rainstorm in 61 years not once stagnant water? Its drainage system and what are the characteristics?

According to an ancient city of Shenyang Architectural experts, the Forbidden City drainage shading two systems. The tomorrow drainage through the flooring to make a pan of water, spit out the faucets discharged to the surrounding river through various outfalls, dark rows of water discharged into the river through an underground drainage channel, and this river is inside and outside Jinshuihe. According to its introduction, the Chengde Mountain Resort is the construction of the drainage system. To sum up, in a word, the entire system by means of light and shade, to reach a purpose: summary row out.

According to experts from the terrain point of view, of Beijing Yanshan North, east Bohai Sea, northwest to southeast, water eastward Nanliu. The view from the Forbidden City, the north gate Shenwu Men horizon elevation of 46.05 meters, the south gate of the Meridian Gate horizon elevation of 44.28 m, a difference of about 2 meters. Drainage facilities to take full advantage of the terrain characteristics built.

The experts say, the total set drainage system characteristics, the east-west direction rainwater sinks into the north-south dry ditch, then into within Jinshuihe.

Dredge each palace courtyard drainage system trunk, Extension, ditches, underground drain, culverts, water ditch eye, carefully measuring, planning, design and construction, annual fixed time scouring dug conservation. It is worth mentioning that the arrangements for a complete drainage system to alleviate the burden of the city outside the city.

Outside the Forbidden City, there are at least three lines of defense: Ming's inner city moat and Tai Ming Ho, Taiping Lake; is the Xiyuan too liquid pool and the sea after; Third outer Jinshuihe and cheese River (moat, the Forbidden City). These canals on the one hand can be used for urban water supply, on the other hand the flood drainage can also be used under the first guarantee will not a lot of rain and flash floods into the Forbidden City at the periphery.

The within Jinshuihe inland of the Forbidden City. A stone coupons hole in the Forbidden City in the northwest corner of the floor easterly Nanhe help is within Jinshuihe inflow intrauterine intakes has control sluice, you can control the water level in case of flood can be turned off.

According to experts, within Jinshuihe cited as a western suburbs Yuquan landscape, the element of gold because the West, "GEM MASTER, the named Jinshuihe," cited by Shenwu Men West trench the moat water inflow intrauterine along the West the vicinity after Wu Yingdian before, to Taihe in front of the Golden Water Bridge under complex through WenYuanGe before to three door, from Luang drive library southeast out of the Forbidden City. "

Within Jinshuihe a total length of over 2000 meters, the river help, the Hedi generic white stone. River winding, or hidden or pass stream the whole Forbidden City. More than for landscaping appreciate hornworts, in the construction of the construction, it is the construction of water sources, and usually also as the city well water, the source of the fire with water outside.

Size over 90 courtyards in the Forbidden City, the drainage ditch through the hospital, the use of the low-lying north to south into the ground near underground drain last convergence in Jinshuihe to, and then to the Donghuamen South corner sluice outflow and outside Jinshuihe confluence.

Forbidden City covers an area of ??72 hectares, the courtyard is in the high-side low north to south, the rain into four weeks the foundations first stone sink, which is open ditch. Obstacles like stairs or buildings are open vouchers hole ie trench eye, and convenient surface water through the obstacles. Ground or open ditch water and then through the inlet into the underground. Inlet square slate Carved into the Ming and Qing coins (big money) shaped, that the cylindrical China engrave into five empty can water, called Qian Yan.

The first three Hall of Hall of Supreme Harmony in the Forbidden City, and the temple, and Paul and the temple, for example, the first three temple built on a 8.13-meter-high three-story platform, LMH railings around the bottom of the discharge storm water holes; each look column under a crafted fine stone leading Dubbed the "dragons" hole through a round hole in its mouth, is also a secondary drainage ducts. Whenever the rain, the rain was ejected from the 1142 drainage holes, showing the the "Qianlong sprinkler landscape, layer by layer whereabouts flow to the hospital, making the countertop no water. The LMH surrounded shicao drains.

First three temple after Sannomiya has a north and south to Imperial Road. Things Palaces such as courtyard also has a north-south corridor. Royal Road corridor are low form high in the middle on both sides, along its terrain, rainwater can be directly from the middle to both sides of the drainage.

Royal Road of the Hall of Supreme Harmony determine for the drainage fluency, in front of the paved ground but also to determine the direction of flow and find a good slope, rainwater catchment to the east and west sides of drainage ditches, also known as the lotus leaf trench, the introduction of hospital the southeast corner of the ditch door berthing under the underground drain inflow within Jinshuihe.

The basic things Palaces Zhu courtyard before and after the two intake and the courtyard between changjie interval. Corridor to the courtyard is divided into two drainage areas, the backyard forward hospital drainage need to determine in advance, for the smooth drainage, water drop slope around the hospital, commonly known as pan of water. The rain since forecourt things on both sides of the ditch door open ditch inflow of Long Street Ditch, and then imported by the Spur Route Center within Jinshuihe.

Because the temples pavilions, rockeries and pavilions, the presence of the fish pond flowers, the Imperial Garden Forbidden City drainage most complex. The specific approach is first divided into two things drains Royal Road to Imperial Garden, during which a number of small drains subdivided. The inlet to the lowest point of each small area as culverts. The underground drain through interconnected with park outside gangou, to form underground drainage network.

North wall in the Forbidden City, the Red Palace wall, before things Lian-fang, one thing to Dagangou, a depth of about 1.5 meters, a width of sixty to seventy centimeters. Rectangular slate above intervals over 20 slabs have four slabs, both sides carved four the Huokou 16 holes together, so that rainwater leaking into. Ditch the western end of the Town God's Temple within the Jinshuihe of interlinked, rain leaked into the premises. The eastern end extends south along the walls of the palace, a north-south vertical dry ditch the rainwater inflow Qing Historica Jinshuihe segment.

In addition, there are three north-south aspect directly enter the within Jinshuihe ditches. A narrow lane of the East Palaces hibernation and Qianlong period, within the latitude of the north, Shenwu Men ditch south bypass the Imperial the tea Shanfang east, and then south to the east within Jinshuihe injected Wenhua. Which by the bifurcation, the West wear Fengxian Temple Nanqun room. Wear clothing from the southwest corner. The injection within Jinshuihe Wenhua West wall to the east of the south, from Arrow Pavilion.

Fourth north-south ditches from the southwest corner of the courtyard of dry clean door piercing, crossing within the right door penetrate the Hall of Mental Cultivation South library, and then by the South Gallery piercing Long were outside, south fold, to Wu Yingdian east of the off Hongqiao at the injection within Jinshuihe.

In addition, East, East, West, inside West Second changjie and other alleys north and south have a short distance to the vertical grooves, respectively, after dry clear door and Qianqinggong is turned eastward West sluicing weft ditch The palace courtyard weft ditch, use of the central high surrounded by low and high northern lower in the south and in the middle of some of the minor groove, both ends of the low natural drop, quick summary of the stormwater discharged into inland outflow extrauterine.