Department of Geography

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Browsing Department of Geography by Author "Bearden, Bennett L."

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    Examining potential impacts of external drivers on environmental instream flows on the Cahaba River, Alabama
    (University of Alabama Libraries, 2018) Luo, Cehong; Praskievicz, Sarah J.; University of Alabama Tuscaloosa
    Water is the key to the lives of all living creatures. Human beings need to ensure there will be safe and abundant water resources in the future. The important issue of water is not only about the water quality, but also about the water quantity. As the most effective indicator of water quantity, instream flow is critical for us to understand the water quantity. It includes the variations of water flows, representing the high and low periods of the river flow. The low flow of rivers is important to preserve the harmony of the environment physically, biologically, and socially. Jowett (1997) pointed out that the minimum flows in rivers and streams provide protection at a certain extent for the aquatic environment. In addition to the creatures that are living within the water, human beings also need water. However, with external drivers, such as climate change, population growth, and riparian policy relaxation, the low period of the water flows in the Cahaba River can be even lower in the future. Hence, this is what this research addresses and why it is critical. This research examines the effects of increasing human activities, such as irrigation and municipal water uses, and climate changes on instream flows in the Cahaba River, Alabama, and indicates what kind of actions might be implemented to prevent negative consequences. The goal of the result of this research is to estimate the possibility that the Cahaba River will be unable to meet the increasing needs of water uses due to the external changes. Based on the results of the scenarios designed in this study, with the external factors, such as climate change, population growth, and riparian policy relaxation, the instream flow of the Cahaba River can be at risk in the future, and we should start to take actions for preventing the trend.
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    Policy implications of aging and manipulated river systems case study: Black Warrior River
    (University of Alabama Libraries, 2012) Wells, Thomas; Bryan, Colgan Hobson; University of Alabama Tuscaloosa
    This dissertation is a policy analysis of lateral connectivity issues on aging and manipulated river systems. The research focuses on associated issues of ecosystem health and human impacts as illustrated in a case study of Alabama's Black Warrior River. The study area on the Black Warrior River, river mile 213 to 292, is representative of other manipulated river systems throughout the United States. The construction of two federally owned locks and dams within the study area created a multi-use inland waterway due to the formation of lentic environments upstream of the regulating structures. The inland waterway's historic management was largely one-dimensional and main channel-oriented. This one-dimensional approach caused a significant deterioration of lateral connectivity. Between 1965 and 2006, the number of open or marginally open entrances to off-channel areas declined from 251 to 119. Open and marginally open off-channel areas decreased 1,125 acres between 1965 and 2006, representing a 26 percent decline. Overall, 643 off-channel acres, regardless of status (i.e., open, marginally open, or closed), were lost during this timeframe, representing a 15 percent decline, and the average and median size of off-channel areas also declined 30 and 53 percent respectively. The decline in lateral connectivity resulted in environmental impacts to the area's fishery and differential effects to a range of stakeholder groups. Policy alternatives were developed and their social impacts assessed to provide decision-makers within the study area and across the United States with options to address lateral connectivity issues.