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.

Trends indicate that wildfires have become larger and more intense over the past few decades. Experts suggest this is due to multiple factors including long-term shifts in land use that disrupt the balance of fuels and fire regimes. Research predicts that climate change will exacerbate this trend but will do so in spatially variable ways across the globe, causing increases in fire activity for some regions and decreases for others. In the United States, increased wildfire activity combined with the rapid expansion of residential development in fire-prone land necessitate billions of dollars in suppression efforts every year to protect human lives and property. The confluence of these issues has catalyzed momentum for communities to actively participate in mitigation at the local level. Yet, the precursor to developing effective solutions is to understand the unique environmental and social components of wildfire hazards at local and regional scales and how these components influence the deleterious impact of fire. This thesis takes a case study approach to understanding and communicating wildfire hazard potential in the Edwards Plateau ecoregion of central Texas. Wildfire simulations were conducted at the regional scale to quantify the magnitude of predicted fire behaviors under various spatial and temporal conditions. Simulations were also conducted within two focal communities to illuminate how patterns of wildfire susceptibility overlap with residential development. Finally, an investigation was made into the emergency response infrastructure and mitigation strategies adopted by each of the focal communities. As a result of simulations under drought conditions, forty-four percent of the study area exhibited flame lengths over eleven feet and ninety-six percent of the tree canopy exhibited crown fire activity. Simulations also revealed an increased potential for crown fire activity and extreme flame lengths along the heavily-populated Balcones Escarpment. Third, physical forms of communities appeared to influence the spatial distribution of burn susceptibility. Finally, the infrastructure and practices of the surrounding region impacted community resilience to wildfire hazards. While these findings are specific to the eastern Edwards Plateau, they showcase how mixed methods can be used to build a comprehensive wildfire hazard assessment for a community. / text

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Thesis (S.T.M.)--Yale Divinity School, 2005. / Abstract. Includes bibliographical references (leaves 62-68).

Thesis (Ph. D.)--University of Washington. / Bibliography: l. 161-176.

Thesis (Th. M.)--Dallas Theological Seminary, 2006. / Includes bibliographical references (leaves [69]-73).

Thesis (Th. M.)--Regent College, Vancouver, BC, 1993. / Abstract and vita. Includes bibliographical references (leaves 207-211).

Thesis (Th. M.)--Dallas Theological Seminary, 1992. / Includes bibliographical references (leaves 41-47).

Thesis (Th. M.)--Dallas Theological Seminary, 2006. / Includes bibliographical references (leaves [69]-73).

Thesis (Th. M.)--Dallas Theological Seminary, 1998. / Includes bibliographical references (leaves [53]-58).