Kunming Urban Atmospheric Environmental Capacity Approved

With the rapid development of industry and economy, emission sources and air pollutant amount are increasing quickly, emission concentration control can not improve urban air quality availably, the key measures is pollutant amount control based on the environmental capacity, which will control air pollution and realize the control aim of air quality.According to the objective of "Implementation Plan for SO₂ pollution prevention in Yunnan acid rain control region 2001-2005", SO₂ emission for 2005 will be cut down by 6.8 percent compared with 2000, SO₂ annual concentration reaches level II stably, and acid rain pollution keeps decreasing. Kunming as one of the seven cities in Yunnan which are listed in the national" acid rain control region" , the air quality has been not optimistic recently. In face of its serious pollution trend, objective for "PLAN", as well as the series problem from urban construction and economy rapid developing, it is very important and necessary to study the atmospheric environmental capacity.Based on the basic factors surveyed which include natural environment, social environment, emission and air quality of Kunming, it analyses the pollution characteristic, variation tendency and sources by means of mathematic statistic and GIS. After analysis of air quality aim, the atmospheric environmental capacity is predicted by model of A-P value method firstly, and aiming at meeting air quality standard. Based on cutting down repeatedly and linking with the pollutant concentration contribution and air quality control target, the atmospheric environmental capacity is secondly predicted by the models simulation of environmental program and ISCLT3.The research range includes municipal territory and urban area of Kunming which is about 20813.3 km² and 398.3 km² respectively. The capacity of municipal territory is 71945 tons for SO₂, 268961 tons for NO_X and 168115 tons for dust. The urban area capacity is 19244 tons for SO₂, 51444 tons for NO_X and 9516 tons for dust. Compared with the emission of the year 2002, SO₂ will be reduced 1413 tons per year, dust and NO_X will get surplus 17900 tons and 493 tons respectively.Models of ISCLT3 and program are found on Gaussian plume model with the character of continuing and steady-state, which is adapted to the urban-scale. ISCLT3(Industrial Source Complex Long-Term Model) is recommended by US EPA, it includes the simulation of point, area and volume sources. Program model is urban multi-emission model, which includes the sources of industry point, industry area, house-hold area and line, traffic line. Based on the regional the emission classes, dispersion parameter and metrological data, a multi-emission model with regional character has been established, and been applied in the study of the atmospheric environmental capacity successfully.GIS as a main technical method has been applied in the analysis of area and data statistic, based on the electronic map with backdrop of road, water system and district, by means of the spatial analysis function of MAPINFO, the location of point, line, area sources are fixed on, classified and gathered.As a result, firstly, according to the analysis of control target, model prediction, pollution cutting down and contribution, a reliable SO₂ capacity has been determined, due to the complicity of original sources and reaction mechanism of dust and NO_X, their capacity will be verified in the future; secondly, the model system from macro-capacity to practical capacity includes the whole process of capacity research, which can be successfully applied in SO₂ capacity research.; thirdly, model of ISCLT3 and program model can simulate well the relationship between emission and air quality, the result from which is coherent very well, and it is suggested to applied in the SO₂ capacity research in medium city; fourthly, the application of GIS and multi-emission pollutant amount control in urban area is innovative in China, the atmospheric environmental capacity model with character of altiplano is new in Yunnan.