Study On The Effect On Drainage System In The Chongqing City Zone By The Three Gorges Project And Its Renovated Technique

Study on the Effect on Drainage System in the Chongqing City Zone by the Three Gorges Project and its Renovated Technique is a sub-subject of Effected on Water Environment in Chongqing Section of Changjiang River by the Three Gorges Project and its Renovated Countermeasure, commissioned jointly by Chongqing Construct Committee, Chongqing Science Committee and Chongqing Environment Protection Bureau. The Study lasted three years, accomplished jointly by Chongqing Environment Science Research Institute and Chongqing City-establishment Management Bureau.The disadvantage effect on the city drainage systems in the TGR Zone especially in the Chongqing city zone by the Three Gorges Project, and its renovated techniques and construct precept are mainly expatiated in this Study. Basic on surveying and analyzing the distributing of city drainage systems and drainage area estuaries, and the characters of the hydro-indexes change after the Three Gorges Reservoir(TGR) forming, the main content, the range and the grade of the effect are also particularly discussed with listing a large mount of surveying data, there are 117.745km drainage pipeline in length and 123 estuaries in the submerge area of the TGR. Those drainage pipeline long under water will severely effect on the function of the drainage, and it will damage the city drainage systems in result. Basic on forecasting on the discharge size of sewage in Chongqing main city zone, the construct and rebuilding precept on drainpipe net system is put forward to aim at the effect on Chongqing drainage system, and the construct engineering quantity is primarily estimated according to the national require of water quality in the TGR. 35km drainage pipeline, 70.5km drainage sub-pipeline, 18.5km rain water pipeline and 37km rain water sub-pipeline are built in the first period of drainage system renovation, and 37.8km drainage pipeline, 75.6km drainage sub-pipeline, 22km rain water pipeline, 44.1km rain water sub-pipeline, 22km press pipeline and 27 drainage stations are built in the second period of drainage system renovation.To protect the water quality in the TGR, the drainage pipeline building and rebuilding are put forward, the scheme of sewage disposal plant in Chongqing main city zone advanced. Tangjiatuo, Jiguangshi, Lijiatuo, Qiezixi, Dadukou and Jingkou sewage disposal plants are planed to build in the scheme. the investment of the scheme is great but its environmental benefit, social benefit and economic benefit are marked.