Analysis About Water Quantity And Quality Of Rainwater Utilized Exemplar Engineering In Centrel Area Of Beijing Olympic Green

Beijing Olympic Central Area is located in northmost of the central axes,whose total area is 84.7 hektare,south is begging at north Fourth ring road,north is end at Kehui raod,west is beside Tianchen east road,east is lean east raod of lake.Central Area includes sight road of central axes,section of tree array,slabstone section of square,subsidence garden,recreational garden,virescence section,the dragon-shape river and non-motor vehicles' road,and so on.Beijing Olympic Green Centrel Area has become the sample of city storm water reclaimation because of its enormous storm water reclaimed system.It has confirmed that the Olympic Centrel Area has characteristics by means of analysis about rain amount and rain water quality in Beijing Olympic Centrel Area from 2005.The Olympic Centrel Area has characteristic of intensively rainfall,rain intensity and rain time,and the middle or small rain is the most important object to collect.It can collect rain water by 13200 cubic meter every year and the reclaimed rate is above 87 percent,which is increased 54 percent than no storm water reclaimed system.The savageness rain quality can satisfy city virescence water,but can't reach standard of third level water.Consistency of contamination is reducing by runoff time extended of non-dankly surface beginning runoff,2 hours later,contamination reduced rate of most contamination can achieve 61 percent to 83 percent,besides that,the contamination is concentrated in runoff of the beginning 30 minutes,and the water qulity can satisfy water quality standard of city virescence after that.The most factor of the dragon-shape river can satisfy the standard of third level water from Sep 2007 to Sep 2009,in particular in 2008,every factor is steady and small.Water quality of pool can water quality standard of city virescence by observation data of 2009.The rainwater collected system in Olympic Centrel Area adopt theoretics of seeping in advance and collecting later,entire engineering is seized of low energy cost,environmental,easy technique,popularize easily,integrated collecting and purifying,which is deserved to be popularized because it avoids the fussy purifying process,therefore,engineering investment and expense management of late stage are also reduced.