Doctoral Dissertation Research: Exurban Land-Use Change, Watershed Management, and Surface-Water Quality

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Rapid urban expansion is a form of urbanization common in the United States, yet its environmental impacts have received limited attention. From a spatial perspective, expansion begins in the exurban fringe, often by replacing agricultural land, yet differences in surface-water quality between exurban and agricultural environments are poorly understood. Numerous social institutions influence expansion's environmental impacts, one being watershed management. Significant resources are devoted to local watershed management, yet uncertainty remains concerning its effectiveness. This Doctoral Dissertation Research Improvement project therefore aims to clarify surface-water quality differences between exurban and agricultural environments and the degree to which participatory and decentered watershed management, as opposed to state-centered management, influences exurban and agricultural surface water quality. The study will employ both quantitative biophysical and qualitative social data and methods. An ordinary least-squares regression analysis for 82 small watersheds in the Cleveland, Ohio, metropolitan area will be based on satellite imagery, aquatic bioassessments, and other spatial data, thereby forming a basis for quantifying relationships between aquatic biodiversity and land use. An intensive, historically based comparative case study of four watersheds will analyze the role watershed management plays in water quality. Data to be used in the project include the regression findings, additional high-resolution spatial data, a survey of Ohio watersheds groups, semi-structured interviews with key watershed stakeholders, and rankings and factor analyses evaluating stakeholder subjectivity. Working hypotheses are that (1) agricultural land use generally fosters relatively greater aquatic biodiversity than exurban land use, although notable variation results from particular local biophysical and social factors, and (2) participatory and decentered watershed management fosters greater aquatic biodiversity than more centralized management.Many Americans want the best possible environmental quality, but they also desire continued economic, population, and urban growth. Urban expansion, an issue of national economic and environmental importance, exemplifies this conundrum. Research findings are expected to help clarify the impacts of urban expansion on surface-water quality, offering additional scientific evidence to the ongoing debate concerning continued urban growth and environmental quality. This study also will shed light on which particular factors affecting water quality are most amenable to watershed management practices or other policy initiatives, thereby helping to determine where best to allocate limited watershed management resources. As a Doctoral Dissertation Research Improvement grant, this award will also provide support to enable a promising student to establish a strong independent research career.