Air pollution simulation has several components, including data preparation, atmospheric circulation and air pollution dispersion modelling and computation, visualization of the model computation results, analysis and model evaluation. Of these components, only atmospheric circulation and air pollution dispersion modelling and computation are mature, while the other components are weak to a greater or lesser extent. To address these weaknesses, this thesis proposes to integrate the data, modelling and analysis into a multi-dimension, virtual geographically referenced environment. In addition, collaboration is used to solve the problem of multi-disciplinary knowledge requirements for conducting air pollution simulation. Based on this model, a concept of collaborative virtual geographic environments (CVGE) is proposed. / The air pollution that is associated with global economic growth is a global problem. Scientists, governmental officials and the public are focusing on improving understanding, accurately predicting and efficiently controlling levels of air pollution. Air pollution simulation is one method used to achieve these goals. This research will consider a computer supported simulation. / The contributions can be drawn from two aspects---CVGE and practice of air pollution simulation. Regarding CVGE, thesis 1 develops the conceptual framework of CVGE; 2 designs the architecture of a CVGE prototype in order to facilitate air pollution simulation; 3 proposes the concept of a "fuzzy boundary volume object", and designs a solution composed of a particle system wrapped in pollution boxes; and 4 examines the levels of geo-collaboration for air pollution simulation. For air pollution simulation, thesis 1 integrates air pollution sources, geo-data, an atmospheric circulation model, an air pollution dispersion model, geo-visualization and analysis into a collaborative virtual geographic environment, which is able to supply a new research methodology and platform for air pollution simulation; in 2, the new platform is scalable and able to free the restrictions of operations on visualization, which paves the way for further extension; 3 couples air pollution dispersion models with geo-information, opening up opportunities for cross studies between air pollution and other research areas, such as the economy, public health and urban planning. / The focus of this thesis is two-fold: one is on the development of a conceptual framework and prototype of CVGE from practice of air pollution simulation; the other is on applying this framework to facilitate air pollution simulation. The work of this thesis can be summarized as follows. (1) Defining the concept of CVGE, developing a conceptual framework for CVGE and discussing primary theories of CVGE. (2) Designing the architecture of a CVGE prototype to facilitate air pollution simulation. (3) Integration and computation of a complex atmospheric circulation model and an air pollution dispersion model based on high performance computation. (4) Geo-visualization of air pollution distribution and dispersion based on calculations using air pollution dispersion models. (5) Geo-collaboration for air pollution simulation. And finally (6) CVGE prototype based air pollution simulation. / The motivation for future research has two main aspects again---CVGE and practice of air pollution simulation. For the aspect of CVGE, possibilities for future research include: 1 more detailed research on the CVGE concept, primary theories and methodologies; 2 the efficient integration and management of heterogeneous geo-models with CVGE in standardization; and 3 the efficient rendering of a complex structured object in CVGE. Regarding practice, future research can be conducted into: 1 extending air pollution dispersion models; and 2 improving the efficiency of air pollutant rendering with a particle system wrapped in pollution boxes. / Xu, Bingli / Adviser: Hui Lin. / Source: Dissertation Abstracts International, Volume: 72-11, Section: A, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 251-264). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

A dynamic air quality modeling system is presented for use in regions of complex terrain. It consists of two pre-processors and the air quality model. TERRAIN is the terrain analysis preprocessor. It accepts as input digitized terrain elevation data and analyses it in terms of the orientation and steepness of slopes. WIND is the second reprocessor, and based on the results of TERRAIN, determines the area in the region where the wind would be channeled or diverted. It produces a pair of wind matrices for the region of interest which give the horizontal and vertical shifts in direction respectively, at each point in the region at several vertical elevations. Each of the preprocessors are executed once for any particular region. The output from WIND is then read into DAMCT. DAMCT is a dynamic air quality model for regions of complex terrain. It accepts as input the matrics from WIND, a source emissions inventory for the region, and a sequence of meteorological conditions. It produces estimates of pollution concentrations at each point in the region at several vertical elevations over time. This data can then be processed by a general contour plotting program to give graphical displays of the concentration levels. This system is designed to be used for a mesoscale region, but can be applied to any size region be simply adjusting the grid size parameter. DAMCT can be run any number of times desired for a particular region after TERRAIN and WIND have been executed. The user can therefore modify the source inventory to reflect potential changes in the region and get an estimate of the effects. Any set up to 25 different meteorological conditions can be used, representing either typical conditions, or worst case conditions, as desired. The system is intended to provide estimates of pollution concentration for the region of interest while still being relatively simple to execute from the user’s point of view. A user’s guide for each program is also given. / Ph. D.