Changzhou City Rainwater Utilization Planning And Residential Area Rainwater Harvesting And Utilization System Design

With the rapid development of society,China has become increasingly dependent on water.At the same time,water quantity in China is uneven between east and west,north and south,and the shortage of fresh water resources is increasingly prominent.By 2030,China will have a water shortage of 40 billion to 50 billion cubic meters,and more than 100 cities across the country will be severely short of water.The "sponge city" project was conceived and promoted at the right moment.Rainwater collection and utilization is an important means to build a "sponge city",a fundamental way to alleviate urban water environment and water resources,and the only way to solve the water crisis.Changzhou city,jiangsu province,is located in the middle and lower reaches of the Yangtze river,with an average annual precipitation of 1091.4mm,total water resources of 3.554 billion m3,per capita water resources of 754m3.Although it does not belong to the water shortage area,However,in recent years,the supporting engineering facilities such as municipal pipe network can not keep up with the rapid development of the city.With the increase of urban population,the proportion of residential areas in cities is increasing.This paper takes rainwater utilization as an important factor in the construction planning of residential areas,studies the methods and technical measures of rainwater collection and utilization in residential areas,and provides different ideas for the construction of sponge cities and the improvement of residential ecological environment.Thesis combines the domestic and foreign research status quo of water recycle,rainwater collection and utilization of classification and analysis of related factors,combined with the changzhou potential water resources situation of changzhou city rainwater utilization is analyzed,according to the hydrological situation of changzhou,rainfall,water pollution condition investigation,discusses the necessity of changzhou city rainwater utilization.Combined with changzhou water project construction and the progress of sponge city project,this paper puts forward some Suggestions and ideas on the utilization and development of rainwater in changzhou.The author investigated the rainy season precipitation of changzhou,2017,through the analysis of the system,that precipitation early environmental pollution is serious,the rainy season precipitation is bigger,underlying surface under the rain washed the polluted water,environmental pollutants concentration is higher and higher,the precipitation for 15 ? 20 minutes later,environmental pollutant concentration along with the precipitation and reduce unceasingly,finally stays the same.The author monitored the water quality of stormwater runoff and put forward that: within the research scope,chemical oxygen demand(COD),total phosphorus(TP)and total nitrogen(TN)in stormwater runoff were positively correlated,so thechange of TP and TN could be understood by determining the COD value of stormwater runoff.At the same time,according to the sampling monitoring data,the initial abandonment flow of 4mm was calculated.The water quality of rainwater after abandonment only needs to be simply treated by the later rainwater treatment system,so as to reach the quality standard of miscellaneous water in the community.Finally,taking a residential area in changzhou city as an example,the utilization of rainwater in the residential area was systematically planned.according to the rainfall balance analysis,the annual water demand of the residential area and the available annual rainwater runoff were calculated,and the feasibility of using rainwater in the residential area as a water source for greening,road pouring,car washing and landscape was demonstrated.According to the calculation of the effective water volume of the rainwater storage system,and according to the demand of the district's 10 days of miscellaneous water consumption,the clear water pool is optimized.According to the comprehensive utilization planning of rainwater in the residential area,various engineering measures are put forward for rainwater collection and utilization of roof,road and green land.The example residential area in the paper combines the man-made landscape with water ecology to protect water resources,improve water ecological environment and save energy.