Publication Date

1988

Document Type

Dissertation/Thesis

First Advisor

Spangler, Timothy C.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Geography

LCSH

Air--Pollution--Mathematical models; Air quality--Mathematical models

Abstract

Standard EPA Gaussian models drastically overestimate surface concentrations when applied to a coastal complex terrain situation under stable conditions. An examination of theoretical and experimental work concerning stable flow in complex terrain shows that blockage of flow by terrain occurs if the stratification is sufficiently strong. This stagnation in the flow is associated with increased horizontal plume dispersion and wind direction meander. Twenty-six test periods from two tracer studies conducted in coastal complex terrain during stagnant flow are examined. Three progressive modifications are made to a standard Gaussian EPA model (MPTER) incorporating the theories of flow in a terrain-blockage stagnation zone. The four models are then evaluated using the tracer-study concentration data. Analysis of the results indicate that the performance of the final modification version model (CONCEPT) is better than that of MPTER when both are applied to dispersion in a coastal complex terrain-induced stagnation zone. Modifications contained in the CONCEPT model include a split sigma modification, a virtual point-source correction, a partial reflection modification, and a partial sector-average modification.

Comments

Bibliography: pages [126]-130.

Extent

vi, 130 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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