Research About The Town Drainage Special Planning In The Catchment Areas Of The Middle Line Of South-to-north Water Transfer Project

Middle line of south-to-north water transfer project is to divert water from the Danjiang kou Reservoir, the catchment areas includes the entire Hanzhong, Ankang,Shangluo of southern Shaanxi and parts of Nanyang, Henan, Hubei shiyan. Because theeastern route project water pollution is serious, the middle water will become the maincomplement of Beijing-Tianjin-Hebei drinking water sources. The Han River, DanRiver of the southern Shaanxi Province region is the middle of south-to-north watertransfer project water protected areas and conservation area, it shoulders the importanttask of ecological and environmental protection of water sources. In order to give fullplay to the role of middle line of south-to-north water transfer project and protect thewater quality of water sources, it is necessary to do specialized planning and design fortown drainage systems in the area.According to the basic requirements of the special drainage planning design, thevarious factors affecting the drainage system were analyzed and different drainagesystems were compared, combined rainfall characteristics and town construction and thebasic requirements of the receiving waters in the catchment areas, the regional drainagesystem selection principle was discussed; Combined the natural environment,topography, water features of southern Shaanxi and so on， the regional design returnperiod rainstorm, runoff coefficient, ground catchment time parameter selection werestudied; Combined social economic and environmental conditions, the town water law,living habits, water function zoning, status of urban water supply and drainage, sewage indicators and sewage treatment discharge standards and the coefficient of variationwere analyzed, the drainage slope control and depth control methods wereresearched.The paper also analyzed several issues need to be addressed of special plansfor urban drainage. The proposed method and the conclusions were applied to Lueyangdrainage special plans and solved some of the problems special plans to drain.The methods and conclusions suggested in the paper can be provided designreference for the drainage system construction in the region, making town drainageengineering design is more in line with basic situation of water source area, makingdrainage system in the region to better serve residents and town services and service forthe protection of water quality.