Development of a decision support tool for assessing impacts of land-use change on groundwater quantity

Land-use change related to human activity affects the quantity and quality of both surface and groundwater. Groundwater is a crucial long-term resource for humans as well as other components of the ecosystem. However, land use impacts on groundwater have received less attention than surface water. With growing population and urbanization across the globe, the demand for potable water is increasing and, as supplies decrease, groundwater is being relied upon more heavily as a freshwater source. Thus, protecting the quantity and quality of groundwater reserves is becoming increasingly important for many communities. In order to protect and manage groundwater resources, policy makers and water managers need science-based decision support tools that use readily available data and that are appropriate for their knowledge and expertise level. However, there is a shortage of such decision support tools. In this dissertation I have attempted to address shortcomings in the current state of land use change science as applied to groundwater resources by examining the reality of how land use change has affected stream baseflow, and by developing a user-driven decision support tool that can be used by planners and decision makers to evaluate the impacts of land-use on groundwater quantity. This decision support tool, known as the ‘Groundwater Supply Tool’, uses readily available data and a simple modeling approach to aid decision making related to long-term groundwater management (availability of groundwater) and sustainable groundwater development in relation to land-use change. It calculates the expected change in water demand with development and relates it to expected availability of groundwater. A simple design, automated flow of data, quick execution, web-based platform, and free availability are some of the virtues of the Groundwater Supply Tool. The results produced from the tool can be used to generate community awareness of potential long-term impacts of land use on groundwater resources