Home Articles A GIS interface for ISCST3 air dispersion model

A GIS interface for ISCST3 air dispersion model

Mujtaba M Shareef


Mujtaba M Shareef
Engineer, Research Institute
King Fahd University of Petroleum and Minerals
Dhahran, Saudi Arabia
[email protected]

A N Khondaker


A N Khondaker
Research Engineer, Research Institute
King Fahd University of Petroleum & Minerals,
Dhahran, Saudi Arabia
[email protected]
Incorporation of complete GIS functionalities with the graphical user interfaces (GUI) for air dispersion models promises better presentation, interpretation and utilization of modeling results, particularly for the end users and decision makers

Due to the continuous increase in world population, the need for energy requirement is unabated. Increased energy demand requires rapid industrialization. Burning fuel is the common process to energy generation. A significant part of this energy is generated by burning fossil fuel such as coal, oil, gas and other products. Combustion of fossil fuel for energy is the major cause of air pollution in most part of the world. As a result, considerable amount of different pollutants are being discharged in the air from both the stationary and the mobile sources. Air emissions from the industries are emitted in the atmosphere through the stacks. Concentration of pollutants emitted from the stacks of different industries however, depend on a number of factors including the type of fuel used, nature of the industry, and combustion process. The fate and movement of emitted pollutants in the atmosphere are influenced by the stack height and geometry, meteorological conditions and the physical and chemical properties of the pollutants.

In order to simulate the dispersion pattern of pollutant emitted from different sources, a number of mathematical simulation models has been developed and supported by USEPA. One of the widely used and accepted models is the Industrial Source Complex (ISC) model that employs Gaussian plume equation. It can be used for short or long term predictions. Usually the short term model, Industrial Source Complex Short Term (ISCST3) is the well accepted and widely used one. The mathematical equation and other assumptions in this model are well documented on the USEPA web site.

Geographical Information System (GIS), which is a general-purpose technology for handling geographic data in digital form is being emphasized currently in air dispersion modeling. Its abilities include (i) preprocessing data into a form suitable for easy analysis, (ii) supporting spatial analysis, and (iii) modeling directly, and post-processing results (Goodchild, 1993). GIS offer a spatial representation of air dispersion pattern adding the spatial dimensions to the traditional air quality database, and it has the ability to present an integrated global view of air pollution. In particular, the visual display capacity of GIS compliments the user interface of air dispersion models, allowing the user to take more complete control of data input and manipulation. Advanced graphical user interfaces can provide user-defined triggers, which allow user to configure different features with respect to environmental changes, and to define appropriate rules to control simulation process (Crosbie, 1996).

Several researchers reported their works related to incorporation of GIS technology in air quality modeling. Moragues and Alcaide (1996) used the GIS to assess and locate traffic effects before and after a new traffic infrastructure enters into services. The results suggested GIS as an effective tool for environmental impact assessment. Gualtieri and Tartaglia (1998) developed a comprehensive model for the evaluation of air pollution caused by road traffic in urban areas to help the decision making of local administrators. Jenson (1998) developed a model which combined GIS and the Danish Operational Street Pollution Model, for population exposure to traffic air pollution in order to improve assessment of health impacts and in support of risk management. Min Der Lin and Yung-Chang Lin (2002) presented a preliminary study for the evaluation of transport-related air pollution situations in an urban area. Sub models used in this study are integrated in a GIS, which is able to utilize spatial information and describe the urban road network and the distribution of the pollutants in the atmosphere.

Different GUIs have also been developed for the ISCST3 model to enhance its user friendliness and easy application. The complete GIS functionalities have not been incorporated in most of these GUI. A standalone GIS interface has been developed for ISCST3 that is one of the most widely used US-EPA regulatory model using ESRI’s ArcObjects library. This paper presents some of the salient features of the developed application with particular emphasis on the challenges involved in applying GIS functionalities to the GUI of ISCST3.