Publication Date

2-1-2003

Degree Type

Master of Science

Abstract

The development of Geographic Information System (GIS) technology has provided techniques for a holistic approach to the study of karst groundwater contamination. While karst groundwaters supply water to a large percentage of the earth's population, its complex environments often have lacked the scientific examination and conservation measures typical of non-karst regions. In this study, GIS methodologies were explored to examine the relationships between land-use and water quality in karst watersheds. Eight watersheds throughout southern and western Kentucky were examined. The study areas included the Mammoth Cave Karst Aquifer, which is the watershed that drains the Mammoth Cave System, and seven watersheds that serve as sources of drinking water. Most of these watersheds exhibit karst geology and, therefore, are highly sensitive to groundwater contamination. Using GIS and remote sensing interpretation, land-uses within these watersheds were classified manually and coded according to the USGS Anderson system (Anderson et al., 1976). The majority of land-uses classified within these basins were agricultural. With the results of land-use analysis, statistical methods were employed in the development of a multivariate, predictive regression model to relate land-uses and contaminants thafhave agricultural land-uses as common sources (fecal coliform, nitrate, phosphorus, alachlor, atrazine, and simazine). Although the regression models resulted in relatively low r2 values (ranging from 0.076 to 0.169), future revisions of the models may increase these values. Potential revisions to the statistical models could include examining other statistical methods and exploring additional independent variables. Using the capabilities of GIS, including buffer analyses, database queries, and digital elevation analyses, areas of potential water quality degradation were located within the study watersheds. Land areas identified through GIS analyses can indicate target areas for implementation of Best Management Practices, information campaigns, incentive programs, and outreach by resource managers, scientists, or agricultural extension offices. High-risk land-uses, including feedlots and row crops, were found to be located in or near locations that may be key to karst groundwater quality (sinkholes, swallets, streams that sink into the subsurface). Such GIS analysis can provide tools to protect ecosystems and be a step toward providing a clean and sustainable drinking water source for Kentucky residents.

Disciplines

Geography | Geology | Hydrology

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