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The Edwards aquifer lies in the structurally complex Balcones fault zone and supplies water to the growing city of San Antonio. To ensure that future demands for water are met, the hydrological and geophysical properties of the aquifer must be well-understood. Fractures often occur in a power-law distribution. Fracture distribution plays an important role in determining electrical and hydraulic current flowpaths. The thesis research presents an evaluation of the controlled-source electromagnetic (CSEM) response for layered models with a fractured layer at depth described by the roughness parameter, BV, such that 0</=BV, associated with the power-law length-scale dependence of electrical conductivity. A value of BV=0 represents homogeneous, continuous media, while a value of 0<BV shows that roughness exists. 1-D synthetic modeling shows that the existence of a fractured layer at depth is apparent in the CSEM time-domain response for models representing aquifers. The research also provides an analysis of the Seco Creek frequency-domain helicopter electromagnetic survey data set by introducing the similarly defined roughness parameter BH to detect lateral roughness along survey lines. Fourier transforming the apparent resistivity as a function of position along flight line into wavenumber domain using a 256-point sliding window gives the power spectral density (PSD) plot for each line. The value of ?H is the slope of the least squares regression for the PSD in each 256-point window. Changes in BH with distance along the flight line are plotted. Large values of BH are found near well-known large fractures and maps of BH produced by interpolating values of BH along survey lines suggest unmapped structure at depth.

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No description available.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 37-39). Also available on the World Wide Web.

Due to increased adoption of irrigation and advancements in technology, producers in the Mississippi Delta have been unsustainably depleting the water stocks in the Mississippi River Valley Alluvial Aquifer (MRVAA). This research investigates the impacts of various regulatory threats uniformly applied to heterogeneously located producers to avert further overexploitation of the MRVAA. If a regulatory threat successfully incentivizes reduction of producers’ extraction rates, costly implementation of a binding limited-use regulation could be avoided. Laboratory experiments incorporating the major characteristics of the MRVAA were conducted to test two threatened uniform policies, limited-use and moratorium. The main finding of the research is that even with the threat of a moratorium, the regulatory trigger point was too lax to result in significantly slowing over exploitation of the water resource.

This study was conducted to provide Grenada, Mississippi an assessment of the current groundwater resources available for use from the Meridian-upper Wilcox Aquifer (MUWX), which is the primary source of groundwater for the city, by creating an accurate groundwater model. Public, private, industrial, and agricultural wells; springs; streams; and surface water bodies all exist within the study area. Groundwater data were collected from local, state, and federal agencies. Well locations, groundwater levels, and well pumping rates were all used in determining the aquifer's characteristics, such as, hydraulic conductivity, discharge, and recharge. Location of the recharge area in relation to a large reservoir was essential in determining the capabilities of recharge to the aquifer, which in turn allowed for a more accurate prediction of groundwater infiltration. Location of wells down-dip of the recharge area was essential in determining the discharge capabilities of the aquifer. This study proved that there is a direct relationship between the current use of the MUWX aquifer in the study area and the ability of the aquifer to recharge sufficiently in order to support its current use. In addition this study also proved that the aquifer would support a large industrial development in the study area and a substantial amount of new public development.

For thousands of years freshwater springs provided the foundations of human settlement in Texas, from Native Americans to Spanish missionaries to German immigrants. However, over the last generation in Texas – and across much of the United States and the rest of the world – water has become just another convenience of modern life, available at the turn of a handle or push of a button. But times are changing. In Texas a perfect storm is brewing as the population booms and water resources deplete, and many people believe water will soon overtake oil as the next big play in the state. Already there is a sustained effort by companies and investors to secure major water assets and rights. At the same time, almost paradoxically, Texans continue to overuse water for lush lawns, poorly suited agriculture, and overtaxed infrastructure without considering the long-term impacts of these habits. As recently as a generation ago, during the previous drought of record in Texas in the 1950s, most Texans either relied on rain for survival – for livestock or agriculture – or knew a family member that did. That connection to water has been all but lost over the last 50 years as reservoirs have brought reliable water supply to an increasingly urbanized population. Now flushing the toilet is as familiar as most people get with the water cycle. Sharlene Leurig, a young woman who is extremely passionate about water in both her professional and personal life, is both a throwback to a different Texas and a promising indicator of how Texans might come to grips with the new water future coming down the pipe. I follow Leurig on her quest to document springs across Texas while also meeting with veteran water experts who’ve spent their lives submerged in the issue. / text

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Thesis (M.S.)--West Virginia University, 1998. / Title from document title page. "December 15, 1998." Document formatted into pages; contains ix, 119 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 109-115).