The Plan Deliberation Of Nanning Flood-control Works Sand River Dike Section Flood Prevention And Drains Waterlogged Land

Nanning, Guangxi Zhuang Autonomous Region capital, is located onthe downriver Yongjiang section, biggest branch Yu Jiang, which is inthe Pearl River basin West River system. It became the firs nationalkey flood prevention city in 1987. In July 2001, Nanning had the biggestflood (about 1 in 10 years) since 1937. So the government lists the cityflood prevention as the key foundation engineering. The flood preventionkey point is to solve two aspects questions: the resistance of out river(YongJiang river) flood and the city waterlogged land drains. TheShaJiang river dike took the Nanning flood prevention system as anindispensable part, is also to solve these two problems with emphasis.This article has mainly conducted the feasibility study fromthese two aspects: On one hand is the flood-control works——flood-damdike line choice, the dike plan determined as well as other buildingswhich relates with the flood-dam, for example, the embankment wharf,the flood prevention drains waterlogged land the floodgate, the dikeirrigation ditch culvert, sluice the construction and so on. On the otherhand is the drains waterlogged land the project——the sand river pumpingstation plan chooses, the pump house design and so on. And this articlehas also provided the strict discussion and the evidence from the environmental effect appraisal as well as the economic evaluation angleto the project feasibility. Thus it has drawn the conclusion:From the engineering construction necessary angle that, The NanningChiangnan area city scale and its locates the status, the existingembankment flood prevention strength with it disconformity should,raise the existing urban district sand river dike as soon as possiblefor this, enable the Nanning Chiangnan area to have a safe life, theproduction, the construction, the investment environment, is extremelyessential, also is extremely urgent. The sand river dike is the Henandike upstream closed end, the Chiangnan piece 50 years as soon as meetsthe flood the defense by east the sand river dike and Henan the dike,west the Henan branch dike, Henan the dike undertakes together. Itsengineering construction extremely necessity.From the plan comparison result that, 1st, flood prevention plan:The old dike line plan, as a result of the plan time, the dike line toois comparatively early curving, does not have the full considerationurban planning construction development need; the garden union new dikeline plan, fully considered urban planning construction the need todevelop, protected southwest the area to go to sea the big channelNanning sand well railroad south station key position and the industry,the thing flows the garden area, increase protection area 5.84km2, thepopulation 30,000 people (plan), the land rose in value approximately 440 million Yuan, has satisfied the Nanning urban planning constructiondevelopment request, has the huge economic efficiency, the socialefficiency and the environment benefit. Therefore, according to the newdike line plan construction the garden is guaranteed Nanning southwesttook the area goes to sea the channel key position city and theAssociation of Southeast Asian Nations exposition permanent conferencesite city strategic request, also is Nanning consummates the urbaneconomy structure and the industrial layout, promotes the city synthesiscompetitive ability the inevitably request.2nd, drains waterlogged land the plan, the process comparison,because a plan consideration plans to construct the pumping station topull out the row of entire basin flood, invests compared to the plantwo, the plan three all slightly, manages the centralism, the movementdispatcher is simple upstream, does not involve the reservoirtransformation and the movement dispatch, has the unitarycharacteristic, finally recommends the choice investment most to save,the submergence few relocates, the examination and approval proceduresimple plan one: The entire basin pulls out the platoon.Focuses from the above project construction necessity and theengineering design economic indicator and the project social efficiencyaspect, the sand river dike rebuilds the project to be supposed toimplement as soon as possible.