Thesis (Ph. D. - Geology)--University of Arizona. / Part of illustrative material fold. in pocket. Bibliography: leaves 243-249.

abstract: ABSTRACT The Phoenix Four Rivers Flora is an inventory of all the vascular plants growing along the Salt, Gila, New and Agua Fria Rivers, and their tributaries in the Phoenix Metropolitan Area during the years of the study (2009-2011). This floristic inventory documents the plant species and habitats that exist currently in the project area, which has changed dramatically from previous times. The data gathered by the flora project thus not only documents how the current flora has been altered by urbanization, but also will provide a baseline for future ecological studies. The Phoenix Metropolitan Area is a large urbanized region in the Sonoran Desert of Central Arizona, and its rivers are important for the region for many uses including flood control, waste water management, recreation, and gravel mining. The flora of the rivers and tributaries within the project area is extremely diverse; the heterogeneity of the systems being caused by urbanization, stream modification for flood control, gravel mining, and escaped exotic species. Hydrological changes include increased runoff in some areas because of impermeable surfaces (e.g. paved streets) and decreased runoff in other areas due to flood retention basins. The landscaping trade has introduced exotic plant species that have escaped into urban washes and riparian areas. Many of these have established with native species to form novel plant associations. / Dissertation/Thesis / M.S. Plant Biology 2011

abstract: ABSTRACT The Sentinel-Arlington Volcanic Field (SAVF) is the Sentinel Plains lava field and associated volcanic edifices of late Cenozoic alkali olivine basaltic lava flows and minor tephra deposits near the Gila Bend and Painted Rock Mountains, 65 km-100km southwest of Phoenix, Arizona. The SAVF covers ~600 km2 and consists of 21+ volcanic centers, primarily low shield volcanoes ranging from 4-6 km in diameter and 30-200 m in height. The SAVF represents plains-style volcanism, an emplacement style and effusion rate intermediate between flood volcanism and large shield-building volcanism. Because of these characteristics, SAVF is a good analogue to small-volume effusive volcanic centers on Mars, such as those seen the southern flank of Pavonis Mons and in the Tempe Terra region of Mars. The eruptive history of the volcanic field is established through detailed geologic map supplemented by geochemical, paleomagnetic, and geochronological analysis. Paleomagnetic analyses were completed on 473 oriented core samples from 58 sites. Mean inclination and declination directions were calculated from 8-12 samples at each site. Fifty sites revealed well-grouped natural remanent magnetization vectors after applying alternating field demagnetization. Thirty-nine sites had reversed polarity, eleven had normal polarity. Fifteen unique paleosecular variation inclination and declination directions were identified, six were represented by more than one site with resultant vectors that correlated within a 95% confidence interval. Four reversed sites were radiometrically dated to the Matuyama Chron with ages ranging from 1.08 ± 0.15 Ma to 2.37 ± 0.02 Ma; and one normal polarity site was dated to the Olduvai normal excursion at 1.91 ± 0.59 Ma. Paleomagnetic correlations within a 95% confidence interval were used to extrapolate radiogenic dates. Results reveal 3-5 eruptive stages over ~1.5 Ma in the early Pleistocene and that the SAVF dammed and possibly diverted the lower Gila River multiple times. Preliminary modeling of the median clast size of the terrace deposits suggests a maximum discharge of ~11300 cms (~400,000 cfs) was necessary to transport observed sediment load, which is larger than the historically recorded discharge of the modern Gila River. / Dissertation/Thesis / Doctoral Dissertation Geological Sciences 2015

The Wellton-Mohawk Irrigation and Drainage District occupies a valley and adjoining mesa along the lower Gila River, in the southwestern part of the State of Arizona. The area has been irrigated for centuries, and now shows problems which reflect past and present water management. First, the water supplies came from the Gila River; later, the groundwater reservoir was used and within about 30 years, groundwater levels declined and salt accumulation, as a consequence of water recirculation, put a limit on attempts to maintain irrigated agriculture. Recently, Colorado River water was brought into the area as the solution to assure permanent large-scale irrigation development. The application of water for crops and leaching of salts caused serious drainage problems. Salinity also caused a problem out of the District as drainage water from the aquifer with high salt content reached the Colorado River and became a source of friction between the United States and Mexico. The water conveyance system in the District is unique in that irrigation water is pumped up the valley into the distribution system. During flood flows along the lower Gila River, this leads to the situation where water is going down the River with little chance to be used, and goes up the valley through a sophisticated conveyance system. Flood flows along the lower Gila River are dependent on infrequent releases from Painted Rock Reservoir, at the upstream boundary of the lower Gila River. The few times they have occurred (2 in 15 years), they created high groundwater levels which were damaging to crop production. The water problems in the District could have short-run solutions through technically possible and economically feasible management practices. The objectives of the study are focused on better use of the water resources, reduction of risks of flood damages, and decrease of salt content of water being diverted to Mexico. A mathematical model was developed to analyze the impact of selected alternatives which could meet these objectives upon the hydrologic system of the District. The application of Strategy I, which proposes the increase of the irrigated acreage by about 5,000 acres, proved to be impracticable under present management conditions since the amount of drainage water to be disposed would be greater than the capacity of the disposal system. Strategies II, III, and IV, which propose increasing levels of change from flood to sprinkler irrigation (25, 50 and 100 rcent) showed results that although not economically encouraging, provide, however, for solution of the internal water problem of the area, and substantial decrease of drainage flow of high salt content delivered to the Colorado River. Strategies V and VI, which proposed reduction by 50 percent or complete elimination of riparian vegetation also proved to be impracticable. Under present management conditions in the District, phreatophytes are an important auxiliary of the water discharge system of the area. Strategies VII and VIII showed that the combination of changes to sprinkler irrigation and reduction of riparian vegetation at levels proposed (50 and 100 percent) practically counteract each other in terms of drainage water to be pumped and does not achieve the proposed objectives. Change in the water management system of the Wellton-Mohawk District would solve its water problems and significantly reduce salinity of the Colorado River water at Morelos Dam, for which hundreds of millions of dollars will be expended in a desalting complex. Drainage from excessive irrigation on the mesa flowing into the valley aquifer is the main cause of high groundwater levels there. Riparian vegetation, although increasing flood damages, is indispensable under the present management system.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1994. / Includes bibliographical references (leaves R1-R8).

Thesis (M.S.)--Dept. of Hydrology and Water Resources, University of Arizona, 1994. / Includes bibliographical references (leaves R1-R8).

There are three recognized species of Siphateles from the Great Basin; S. alvordensis, S. boraxobius and the tui chub, S. bicolor. One species, S. boraxobius, is endangered and one population of tui chub at Hutton Spring is threatened. Despite several morphological and molecular studies, the taxonomy and relationships of tui chubs are unclear. A recurrent theme in prior studies has been the possibility of translocation of tui chubs, especially into Summer Lake Basin, and probably by bait bucket introductions. I approached this problem by using cytochrome b (cyt b) sequences to define clades and constructed a neighbor-joining tree to examine relationships. Developmental ontogeny and adult meristic characters were used to corroborate clades, and microsatellites (nDNA) used to explore the possibility of hybridization among Summer Lake Basin fish and those from surrounding basins. The cyt b tree recovered a basal polytomy containing a western clade from Sycan Marsh, an eastern clade from the Alvord Basin, and S. bicolor. The Sycan Marsh clade was represented by two fish and requires additional research. Within the Alvord Basin, S. boraxobius and S. alvordensis were well corroborated by morphological characters but sequence divergence was only 0.37%. There were three major clades in S. bicolor – a basal S. newarkensis clade in Nevada, an Oregon Lakes S. bicolor clade, and, sister to it, a disjunct S. obesa clade in Nevada and the Oregon Lakes. In the Oregon Lakes, there were two clades within S. bicolor: S. thalassinus was sister to the remaining S. bicolor and there were two clades within S. obesus: S. oregonensis was sister to a "Summer Lake Basin" clade. There was some morphological corroboration for S. oregonensis, but no corroboration for the others. Clades were geographically disjunct or not confined to single basins. The S. oregonensis clade was sister to a Nevada polytomy and historical evidence implicates that at least one population of S. oregonensis in XL Spring was introduced in the late 1800's. Average sequence divergence with the Nevada clade, 0.62 - 0.88%, did not seem to support possible Miocene or Pliocene vicariance scenarios. Elsewhere, the S. thalassinus clade was found outside of Goose Lake in Summer Lake Basin and the "Summer Lake Basin" clade was found in Goose Lake Basin. Clustering of three microsatellite loci did not match cyt b clades, rather, individuals clustered based on sample location, suggesting that the cyt b patterns were due to introgression. In Summer Lake Basin, evidence of poisoning and subsequent transplants was consistent with these observations. These results suggest the presence of three or four tui chub taxa in the Oregon Lakes and Alvord Basin, however translocation and subsequent introgression appear to have been common in many populations, and will prove challenging for taxonomists and conservation managers. / Graduation date: 2013

No description available.

Cover title: Draft technical appendix. / Phoenix Urban Study: Final Report / The work upon which this publication is based was supported by funds provided by the U.S. Army Corps of Engineers, Los Angeles District, as authorized by resolution of the Senate Public Works Committee on July 31, 1973. This report was prepared as a contribution to the Phoenix Urban Study under auspices of the U.S. Army Engineer District, Los Angeles.

Master of Science / Department of Biology / Keith B. Gido / The upper Gila River basin in southwest New Mexico, USA is one of the few unimpounded drainage basins in North America and is a stronghold for the unique and endemic fishes west of the Continental Divide. Multiple non-indigenous fishes have been introduced to the Gila River and are a potential threat to native fishes, yet very little is known of the trophic ecology of the native and nonnative fishes. We used diet and stable isotopes collected from native and nonnative fishes to identify their trophic relationships and evaluate potential interactions in the upper Gila River basin during June-July, 2007 and 2008. Diet and stable isotope data indicated aquatic invertebrates were the primary food for both native and nonnative fishes. Native large-bodied fishes were mainly algivore/detritivores and native small-bodied fishes were primarily insectivores. Small-bodied nonnative fishes fed on detritus and aquatic invertebrates. Nonnative predators preyed on small-bodied fishes and predaceous aquatic invertebrates and had higher trophic positions than all native fishes. Although nonnative predators did not rely exclusively on native fishes as prey, their presence extended community food-chain lengths, and the combined predation on juvenile native fishes by multiple apex predators may threaten persistence of native fishes. The lack of concise evidence for negative effects suggested that impacts of nonnative predators were more subtle and confirmed the underlying complexity of a relatively simple community The extensive database on feeding relations of Gila River fishes allowed us to further understand how energy moves through ecosystems. Specifically, the goal of chapter two was to characterize variation in fish-community food web structure within and among study reaches on the Gila River using [superscript]13C and [superscript]15N stable isotopes. We hypothesized that food web structure would reflect variation in fish community structure, resource availability and environmental conditions across habitats. Food web structure in isotope bi-plot space was estimated using community-wide measures of trophic structure, mean trophic position, and food-chain length. Permutational multivariate analysis of variance indicated that indices of food web structure were more variable among than within reaches and this pattern was primarily associated with variation in trophicl area occupied by taxa in isotope bi-plot space and mean trophic position of those taxa. Variation in food web structure was significantly associated with fish species richness across macrohabitats but was weakly associated with abiotic reach-scale factors. Variation in food web structure was concordant with variation in fish community composition and suggested that factors influencing the distribution of fishes also influence food web structure.