Thesis (Ph. D. - Renewable Natural Resources)--University of Arizona, 1986. / Includes bibliographical references (leaves 90-92).

A study of the flora of Leslie Gulch Malheur County, Oregon was undertaken to elucidate the relationships of the flora and of the endemic species in the flora, and to determine if these endemic species are restricted to their present distribution by chemical factors of their substrate. A checklist of native plants and a description of the major communities was made and floristic relationships were studied. Chemical and mineralogical tests such as emission spectrography, x-ray diffraction and cation-exchange capacity as well as physical tests such as particle-size distribution and gravimetric water content were performed. The results of the tests gave no indication of any chemical factor which may restrict the distribution of plants. A zeolite, heulandite, is present in 'the ash-tuff which is the substrate for the endemic species Mentzelia packardiae Glad and Senecio ertterae Barkely. However, this would not restrict plant growth. It was concluded that the distribution of the endemics Senecio ertterae Barkley, Mentzelia packardia Glad, Ivesia rhypara Ertter & Reveal, Eriogonum novonudum Peck, and to some extent Astragalus sterilis Barneby and Trifolium owyheense Gilkey is determined primarily by physical factors of their substrates, and that they are pioneer species which may be competitively excluded from normal sites. Artemisia packardiae Grimes & ertter ined. is a species which is restricted by a diminishing relic habitat. The flora of Leslie Gulch has been complicated by interaction of a northern mesic association and a southern xeric association. The endemic species Mentzelia packardiae and Senecio ertterae are recent species which evolved from a southern Great Basin flora which has moved north with the retreat of the last ice sheets. Ivesisa rhypara and artemisia packardiae are recent species which evolved from a northern flora which followed the retreat of the ice sheets north.

Thesis (M.S. - Renewable Natural Resources)--University of Arizona. / Includes bibliographical references.

Distributed rainfall-runoff models are gaining widespread acceptance; yet, a fundamental issue that must be addressed by all users of these models is definition of an acceptable level of watershed discretization (geometric model complexity). The level of geometric model complexity is a function of basin and climatic scales as well as the availability of input and verification data. Equilibrium discharge storage is employed to develop a quantitative methodology to define a level of geometric model complexity commensurate with a specified level of model performance. Equilibrium storage ratios are used to define the transition from overland to channel-dominated flow response. The methodology is tested on four subcatchments in the USDA-ARS Walnut Gulch Experimental Watershed in southeastern Arizona. The catchments cover a range of basins scales of over three orders of magnitude. This enabled a unique assessment of watershed response behavior as a function of basin scale. High quality, distributed, rainfall-runoff data were used to verify the model (KINEROSR). Excellent calibration and verification results provided confidence in subsequent model interpretations regarding watershed response behavior. An average elementary channel support area of roughly 15% of the total basin area is shown to provide a watershed discretization level that maintains model performance for basins ranging in size from 1.5 to 631 hectares. Detailed examination of infiltration, including the role and impacts of incorporating small-scale infiltration variability in a distribution sense, into KINEROSR, over a range of soils and climatic scales was also addressed. The impacts of infiltration and channel losses on runoff response increase with increasing watershed scale as the relative influence of storms is diminished in a semi-arid environment such as Walnut Gulch. In this semi-arid environment, characterized by ephemeral streams, watershed runoff response does not become more linear with increasing watershed scale but appears to become more nonlinear.

Almost all runoff-producing rainfall on small watersheds (100 square miles and less) in southeastern Arizona results from air-mass thunderstorms. On large watersheds (1,000 square miles and greater) frontal systems which may include thunderstorm activity or snowmelt produce the major flood peaks as well as much of the annual runoff. Air-mass thunderstorms are of short duration and limited areal extent, and generally occur in the late afternoons and early evenings in July, August, and September. Runoff-producing rainfall may occur from frontal-convective systems at any time although they are most common in southeastern Arizona in September. Rainfall and runoff records have been collected from the 58- square-mile Walnut Gulch rangeland watershed near Tombstone in southeastern Arizona by the Agricultural Research Service since 1954. These data represent the best information available on thunderstorm rainfall-runoff relationships in the Southwest. At present there are 95 recording rain gages and 22 permanent runoff-measuring stations on the Walnut Gulch watershed. Runoff-producing thunderstorm rainfall is extremely variable both in time and space, and is therefore difficult to measure accurately and define precisely. Isohyetal mapping for rainfall from individual thunderstorms both for total rainfall and shorter durations within the storm provides good qualitative information, and also provides some quantitative limits on storm movement, intensities and volumes, and areal extent. Runoff records from Walnut Gulch and other Arizona watersheds indicate that peak discharge and runoff volume from individual thunderstorms decrease with increasing watershed size because of the limited areal extent of runoff-producing thunderstorms and because cf the increasing channel abstractions with increasing watershed size. Channel abstractions greatly alter runoff hydrographs as flood surges move through the ephemeral channel system. Five major runoff-producing thunderstorms on Walnut Gulch between 1957 and 1967 were used to develop a model for the maximum expected rainfall in southeastern Arizona. The model was based on maximum 30-minute point rainfalls within the average 60-minute runoff-producing thunderstorm. Over 2.5 inches of rainfall has been recorded in 30 minutes on Walnut Gulch during 3 thunderstorms in 15 years of record (1955-1969). A thorough search of U.S. Weather Bureau and other records indicated that no storms of this combined intensity and magnitude have been recorded in Arizona. Therefore, for design purposes, the expected mean 30-minute rainfall for southeastern Arizona was estimated as 3 inches. Regression analysis was used to estimate peak discharges for major runoff events on Walnut Gulch and to develop a rainfall-runoff model for Walnut Gulch. Peak discharges were correlated with the maximum 30-minute rainfall, which was considered the core of runoff-producing rainfall for major runoff events. Antecedent channel conditions and distance between watershed outlet and runoff-producing rainfall had little effect on the correlation. The coefficients of determination for the regression equation correlating thunderstorm rainfall and peak runoff were 0.92 and o.84 for watershed 5 (8 square miles) and watershed 1 (58 square miles), respectively. With the model for maximum expected rainfall and the rainfall-runoff model for estimating peak discharge from maximum 30-minute rainfall, maximum discharge for the 58-square-mile Walnut Gulch watershed was 23,000 c.f.s. Assuming a normal distribution of errors, within 95 percent confidence limits, the limits were 19,000 and 27,000 c.f.s., and assuming the Chebyshev inequality, the limits were 15,000 and 31,000 c.f.s. Recurrence intervals for 20-, 50-, and 100-year storms and the maximum peak discharges were developed for small watersheds (100 square miles and less) from Walnut Gulch data. The curves were compared to a family of curves for Arizona watersheds up to several hundred thousand square miles. The family of curves based on Walnut Gulch data were much steeper, strongly suggesting that there are 2 families of curves, one steeper family for the small watersheds (100 square miles and less) which is based on runoff peaks from air-mass thunderstorms, and another flatter family of curves for the large watersheds (1,000 square miles and greater) which is based on runoff peaks from frontal-convective systems and snowmelt. The 2 families of curves probably intersect between 100 and 1,000 square miles.

The Jurassic Twist Gulch Formation of central Utah was deposited in the active Arapien sub-basin of the Western Cordillera foreland trough. We herein demonstrate the utility of integrating facies analysis, terrestrial sequence stratigraphy, and detrital zircon (U-Pb) ages to improve paleogeographic reconstructions as well as identify regional unconformities, locate fluvial depocenters, and infer sediment supply/accommodation space ratios. Strata of the Twist Gulch Formation in Pigeon Creek Canyon (PCC) near Levan, Utah consists primarily of alluvial deposits, while in Salina Canyon (SC) the Twist Gulch Formation is comprised of a mix of alluvial and marginal marine deposits associated with the Jurassic Western Interior Seaway. Within the PCC section, a change from high accommodation system (HAS) mudstones to low accommodation system (LAS) multi-storied channel sandstones and back to HAS deposits exists. This same pattern exists in the SC section but culminates with marine deposits. Terrestrial sequence stratigraphy predicts that the change from HAS to LAS deposits indicate a sequence boundary and thus an unconformity. The J-3 unconformity, a regional unconformity on the Colorado Plateau, separates strata of Callovian age from Oxfordian age in Utah. Using detrital zircons (U-Pb), the first radiometric ages were obtained for the Twist Gulch Formation. The J-3 unconformity is bracketed by detrital zircon (U-Pb) ages and stratigraphic relationships in the study area. These new ages suggest that the Twist Gulch Formation is time-equivalent to the Entrada Sandstone, Curtis, and Summerville formations of the Colorado Plateau. Further, integrating facies analysis, terrestrial sequence stratigraphy, and detrital zircon (U-Pb) ages predicts that the PCC section was an active depocenter during the early Oxfordian in which sedimentation outpaced accommodation space, prograding the Oxfordian shoreline of the Jurassic Western Interior Seaway shoreline eastward. This integration process also predicts that subsurface sandstones positioned above the J-3 unconformity on the west side of the Wasatch Plateau are of a different age, depositional system, and systems tract from subsurface sandstones on the east side of the Wasatch Plateau.

Thesis (M.A.)--University of Wyoming, 2007. / Title from PDF title page (viewed on June 16, 2009). Includes bibliographical references (p. 63-70).

Thesis (Honors)--College of William and Mary, 2008. / Includes bibliographical references (leaves 80-85). Also available via the World Wide Web.

Thesis (M.A.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed July 17, 2007. Includes bibliographical references (p. 93-101).

The purpose of this thesis is to raise awareness about the contribution historic signs make to the experience of a place. Illuminated signage has played a key role in the development of the American landscape. The relationship between illuminated signage and sense of place is complex. Because of the ephemeral nature of signs and the public perception of them as advertising tools, the preservation community frequently overlooks signs. By examining three case studies, this thesis presents three different approaches to the preservation of illuminated signage. The first case study is the 2002 New Mexico Route 66 Neon Sign Restoration Project. This case uses Route 66 to examine the preservation of original material in original location. The second case study is the 2002 Amendment to the New York City Zoning Regulations, which mandates signage saturation in Times Square. This case examines the preservation of the experience of Times Square by protecting the historical use of innovative signage. The third case study is the 1996 installation of restored illuminated signs by the Neon Museum in Las Vegas at the Fremont Street Experience. This case examines the collections approach to preserving original Las Vegas illuminated signs in an outdoor museum setting as public works of art. While these three case studies evaluate iconic locations, the lessons are broadly applicable. The preservation approaches outlined here illustrate that every situation is unique and requires a full analysis of the context of the sign. Preservationists should evaluate signage within their local communities by examining the artistry and materiality of the signs. However, it is equally important to evaluate the overall community context of the signs. In order to preserve the experience of historic illuminated signage, it is imperative that preservationists and the general public understand that there are numerous approaches to safeguarding these works and that the time to take action is now. / text