城市空气质量GIS数据模型及分析系统的集成与应用

城市空气质量模拟是目前环境与健康研究的一个重要领域。本文基于GIS技术,采用准稳态高斯扩散模型建立了城市空气质量模拟系统,着重研究了三维空间城市空气质量模型系统的集成方法,并以福州市为例,采用该模型系统对城市建城区的NO₂与SO₂年平均浓度场分布进行了模拟。

Integration and Application Method to Urban Air Quality Simulation System Based on GIS

At present,the air quality simulation has become a main concern in environmental research.The article mainly presents method to the structure simulation system for urban air quality based on spatial analysis model of GIS,especially discussing the integration and application of air quality model in detail by taking Fuzhou City as an example. Air quality simulation integration system comprises three sub-systems of air-pollution spatial data base,air-quality model system,and analysis and mapping system,primarily simulating mean concentration distribution of air pollutants on urban local scale.Of the three sub-systems,air quality model system is the core of the whole simulation system integrating emission,dispersion and photochemical transformation models of three kinds of air pollution sources of point,line and area.Area-source model and photochemical transformation model of air pollutants are two important breakthroughs.Area-source model which is built based on spatially finite difference method can efficiently simulate emission and dispersion from various agricultural land uses including grassland and woodland besides urban low-point sources and resident lives.Photochemical transformation model structured on the basis of O3-NOX system is integrated into dispersion model of point source,line source and area source,which significantly improve the simulation precision of NO2 and indirectly solve concentration field simulation of a second pollutant of O3. Because dispersion process of pollution sources is simulated on the basis of Quasi-stability Gauss Pattern,the application of urban air-quality modeling system must meet three premises: 1) air sources emit continuously;2) pollution dispersion is independent of circumfluence from street canyon;and 3) only three time series of two traffic summits and one non-summit are simulated within a single day.