Assessing the impact of long -term land use changes on water quality in eastern Massachusetts.
Item
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Title
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Assessing the impact of long -term land use changes on water quality in eastern Massachusetts.
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Identifier
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AAI3325454
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identifier
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3325454
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Creator
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Tu, Jun.
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Contributor
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Adviser: Zong-Guo Xia
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Date
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2008
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Language
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English
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Publisher
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City University of New York.
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Subject
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Geography | Environmental Sciences | Urban and Regional Planning
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Abstract
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Over decades, land uses in the United States have been changing rapidly, causing a sharp decline of agriculture area and forest and a significant increase of urban land. Such changes alter the surface characteristics of watersheds that can have considerable influence on water quality and quantity. The goal of this dissertation is to assess the impact of long-term land use changes on water quality since 1970 in eastern Massachusetts by integrating GIS (Geographic Information System), statistical and spatial analyses, and hydrologic modeling. GIS and statistical analyses are applied to analyze the spatial and temporal relationships between water quality and land use, to determine the appropriate spatial scale for such investigations, and to uncover the predictors of water quality change. A recently developed spatial statistical technique, Geographically Weighted Regression (GWR), is adopted to explore the spatially varying relationships. A hydrologic modeling system, AVGWLF, is used to simulate the continuous historical streamflow and nitrogen load, and to project the future conditions under different climate and land use change scenarios.;The main findings are: (1) significant spatial relationships exist between land use and water quality; (2) long-term water quality change is affected by land use changes but does not have consistent response to the rate of land use change; (3) relationships between land use and water quality are affected by spatial scales and also change over space; (4) impact of land use changes caused by urban sprawl is more significant in less-urbanized watersheds in suburbs than in highly-urbanized watersheds in central cities; (5) future climate and land use changes will have significant impact on streamflow and water quality; and (6) the future impact will be more on changing the seasonal distributions than on altering the average annual amounts of the streamflow and water pollutant load.;The dissertation develops a set of fresh approaches to tie land use changes to water quality, which can be easily applied in other areas. It improves the understanding of the mechanism of water quality in response to land use changes. It also provides useful information to government and policy makers for practical applications in land use planning and water resource management and conservation.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
