Study On The Two Rivers Water Environment Capacity In Chongqing City

After the Three Gorges reservoir, the water area of the reservoir becomes wider,slower, weaken the self-purification ability, is more sensitive to the change of pollutants.The two rivers in Chongqing city is the main water supply source of the city, the waterquality of Chongqing city life, industry, agriculture and water conservancy has a crucialrole, related to the economic development of Chongqing city. Therefore, two river waterenvironmental capacity of the main urban area of Chongqing, has important theoreticaland practical significance.This study first water quality status of Chongqing city conducted acomprehensive survey and assessment of water quality, this study identified CODcr asthe control factor, using the two rivers in Chongqing city water quality mathematicalmodel is established to simulate the MIKE21software, the confluence of the two riversmouth pollution mixing zone of typical sewage outfall, and according to the waterenvironment capacity calculation formula to calculate the total two river waterenvironmental capacity in Chongqing urban area, the relationship between economicstructure and the water environmental capacity, allocation of water environmentalcapacity.The main conclusions are as follows:First, through the investigation and assessment of water quality of Yangtze Riverin Chongqing City, the overall water quality exceed the standard section of the project ismainly COD, Hg, ammonia nitrogen. A section of individual water period, exceed thestandard Pb Oil. Other water project with I, II, III water quality standard.Second, MIKE21is used to establish the two-dimensional water quality model,determining its parameters and boundary conditions, hydrological and water qualitydata were measured through parameter calibration, calculation of the junction of typicalsewage outfall pollution mixing zone area, length and width, the pollution mixing zone’slength is811.3m, the shortest outfall length is132.6m; the most wide sewage outletwidth is333.2m, the most narrow outfall, only56m.Third, by calculation of hydrological frequency of Chongqing city two rivers andthree hydrological stations of the hydrological data, to determine the90%guarantee thedesign flow rate of each hydrological station, according to two rivers in Chongqing city water quality standard, the control section water quality compliance method to calculatethe main city of Chongqing river water environmental capacity,63300t/a.Fourth,simulation of the economic structure and the water environmental capacityof Chongqing urban districts, with output value of water environmental capacity furtherweight distribution, combined with the dynamic economy, adjust the waterenvironmental capacity has been determined, are commensurate with the main citydistrict economic development of the water environmental capacity.