Author: Frederick Ayivi

Publisher:

Published: 2017

Total Pages: 208

ISBN-13:

"The quality of rivers and streams are affected by the land-use-land-cover (LULC) compositions that are present within their watersheds and riparian buffers. Hence, understanding how these LULC compositions, present within watersheds, influences water quality of these water bodies is very important for river management and restoration. This dissertation research was undertaken with the goal of examining the effects changing LULC on stream system. The research was conducted in the Reedy Fork Buffalo Creek watershed in Guilford County, North Carolina to provide a study area of streams within a nested watershed assemblage with a variety of sub-watersheds and varying LULC proportions for comparison. Toward this end, LULC spatial fragmentation of the Reedy Fork Buffalo Creek watershed was quantified for the 2002 through 2013 study period based on remote sensing data. This watershed is located at the headwaters of the Cape Fear River basin, the largest river basin in North Carolina. Analysis of how river flow and several water quality variables were related to landscape attributes at three scales: 100 m, 150 m, and watershed was then performed. The Soil and Water Assessment Tool (SWAT) was used to examine the contribution of LULC to water yield and nitrate loadings in the year 2030 relative to future LULC change scenarios. Results show that the water quality of the Reedy Fork Buffalo Creek changed significantly during the recent decades. These changes in space and time indicate a trend of accelerating deterioration in water quality. Also, LULC pattern had major impacts on the flow and water quality of the Reedy Fork Creek at multiple spatial scales. In particular, impervious LULC, although small in percent cover, exerted a disproportionately large influence both locally and over distance. Results also show that most water quality variables (Conductivity, hardness, nitrate, TKN, and Turbidity) were correlated with landscape pattern on all three spatial scales although the correlation was stronger at the watershed scale than at the buffer scales. Additionally, results from the scenario analysis shows that, compared to the current situation (2010), a 13.5% increase in surface runoff, 9.26% increase in water yield, and 31.85% in increase in nitrate yield was recorded for 2030. These increases were due to the conversion of forest and grass into impervious surfaces. The research highlighted the probable role of the interactions between LULC spatial distribution and water quality. This scale multiplicity suggests that, while water-monitoring and river restoration need to adopt a multi-scale perspective, particular attention should be paid to the watershed scale. In the context of population growth and increasing urban development continuing into the 21st century, preservation and restoration of vegetative LULC and the elimination of impervious surfaces within the watershed should be a primary concern for the general public, the scientific community, and public policy decision makers."--Abstract from author supplied metadata.