This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

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.

No description available.

A continuous simulation streamflow model (i.e., SSARR - an acronym for Streamflow Synthesis and Reservoir Regulation) was evaluated and used to study winter streamflow from the Salt River Basin. This 4,306 square mile basin, which ranges in elevation from 2,200 to 11,500 feet, is associated with a diversity of watershed, vegetation, climatic and hydrologic characteristics. Program modifications allowed computation of potential evapotranspiration within the model. This provided improved flexibility in delineating simulation units and reduced the necessary time-dependent data inputs to daily values of precipitation and temperature. Refinement of initial parameter estimates and relationships was accomplished by trial and error methods. Four years of hydrometeorological data were utilized for model calibration and an additional four years used to test the validity of parameter estimates. Simulated hydrographs generally underestimated peak flows and overestimated recession flows following major rainfall events. The standard error of the estimate for simulated winter flows (November through May) was only 30,000 acre-feet for the calibration period but increased to approximately 120,000 acre-feet for the validation period. Average winter flows during the calibration and validation periods were 840,000 and 690,000 acre-feet, respectively. Approximately 25 to 45 percent of the winter runoff occurring after February 1, March 1 and April 1 could be predicted from simulated snowpack water equivalent and soil moisture conditions on the prediction date. High elevation portions of the basin were more efficient at producing streamflow from a given precipitation input than were the lower elevations. Maximum daily watershed efficiencies (ratio of generated runoff to rain and snowmelt inputs) usually occurred on the date of snowpack disappearance for the relatively high elevation simulation units. Simulated runoff volumes increased exponentially with increased basin precipitation but decreased linearly with increased basin air temperatures. For a selected winter period, simulations indicated streamflow response to a one-inch change in winter precipitation would be approximately 100,000 acre-feet, or 3.4 times greater than expected from a one-degree change in winter temperature.

No description available.

abstract: Switching surges are a common type of phenomenon that occur on any sort of power system network. These are more pronounced on long transmission lines and in high voltage substations. The problem with switching surges is encountered when a lot of power is transmitted across a transmission line/network, typically from a concentrated generation node to a concentrated load. The problem becomes significantly worse when the transmission line is long and when the voltage levels are high, typically above 400 kV. These overvoltage transients occur following any type of switching action such as breaker operation, fault occurrence/clearance and energization, and they pose a very real danger to weakly interconnected systems. At EHV levels, the insulation coordination of such lines is mainly dictated by the peak level of switching surges, the most dangerous of which include three phase line energization and single-phase reclosing. Switching surges can depend on a number of independent and inter-dependent factors like voltage level, line length, tower construction, location along the line, and presence of other equipment like shunt/series reactors and capacitors. This project discusses the approaches taken and methods applied to observe and tackle the problems associated with switching surges on a long transmission line. A detailed discussion pertaining to different aspects of switching surges and their effects is presented with results from various studies published in IEEE journals and conference papers. Then a series of simulations are presented to determine an arrangement of substation equipment with respect to incoming transmission lines; that correspond to the lowest surge levels at that substation. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018

Thesis (M.P.A. - Public Administration)--University of Arizona, 1968. / Includes bibliographical references (leaves 98-100).

abstract: Worldwide, riverine floodplains are among the most endangered landscapes. In response to anthropogenic impacts, riverine restoration projects are considerably increasing. However, there is a paucity of information on how riparian rehabilitation activities impact non-avian wildlife communities. I evaluated herpetofauna abundance, species richness, diversity (i.e., Shannon and Simpson indices), species-specific responses, and riparian microhabitat characteristics along three reaches (i.e., wildland, urban rehabilitated, and urban disturbed) of the Salt River, Arizona. The surrounding uplands of the two urbanized reaches were dominated by the built environment (i.e., Phoenix metropolitan area). I predicted that greater diversity of microhabitat and lower urbanization would promote herpetofauna abundance, richness, and diversity. In 2010, at each reach, I performed herpetofauna visual surveys five times along eight transects (n=24) spanning the riparian zone. I quantified twenty one microhabitat characteristics such as ground substrate, vegetative cover, woody debris, tree stem density, and plant species richness along each transect. Herpetofauna species richness was the greatest along the wildland reach, and the lowest along the urban disturbed reach. The wildland reach had the greatest diversity indices, and diversity indices of the two urban reaches were similar. Abundance of herpetofauna was approximately six times lower along the urban disturbed reach compared to the two other reaches, which had similar abundances. Principal Component Analysis (PCA) reduced microhabitat variables to five factors, and significant differences among reaches were detected. Vegetation structure complexity, vegetation species richness, as well as densities of Prosopis (mesquite), Salix (willow), Populus (cottonwood), and animal burrows had a positive correlation with at least one of the three herpetofauna community parameter quantified (i.e., herpetofauna abundance, species richness, and diversity indices), and had a positive correlation with at least one herpetofauna species. Overall, rehabilitation activities positively influenced herpetofauna abundance and species richness, whereas urbanization negatively influenced herpetofauna diversity indices. Based on herpetofauna/microhabitat correlations established, I developed recommendations regarding microhabitat features that should be created in order to promote herpetofauna when rehabilitating degraded riparian systems. Recommendations are to plant vegetation of different growth habit, provide woody debris, plant Populus, Salix, and Prosopis of various ages and sizes, and to promote small mammal abundance. / Dissertation/Thesis / M.S. Applied Biological Sciences 2011

abstract: The Phoenix area had no sizable Mexican presence before the U.S. took over the territory. Some assumed that the region was founded completely by whites from the outset. Whites and Mexicans actually held nearly equal populations throughout the first two decades of settlement. Though they did not hold equal status, their cohabitation was largely characterized by mutual interdependence and respect. Transforming the Salt River Valley's desert terrain into a regional agricultural hub depended on the Sonorans' preindustrial skills. As the town modernized, a new class of resident sought large scale projects to integrate Phoenix into the U.S. economy. Two pivotal projects achieved this. First, railroad spur lines made Phoenix accessible for migrants, as well as allowing farmers to supply commercial markets profitably. Second, the massive Roosevelt Dam secured a stable water supply for valley farmers. While these projects provided the foundation for development, it was cotton that brought commercial success. Throughout World War I, valley cotton growers capitalized on the booming cotton market by expanding their average acreage from 400 acres in 1912 to 130,000 acres in 1920. This rapid escalation to meet wartime demands depended upon a massive seasonal labor force from Mexico. While this boom brought prosperity to valley farmers, it solidified the Mexican's role in the Salt River Valley as little more than a laborer. Valley cotton growers impressively managed all labor issues through a well-organized collective association. Over-recruitment and wage setting kept workers from collective bargaining for better wages. The cotton growers' hegemony crashed along with cotton prices in 1921. Though the industry recovered fairly quickly, the cotton growers faced a new challenge in the rising national clamor to restrict Mexican immigration to the U.S. Though growers fought restrictions in Congressional hearings throughout the decade, the economic crash of 1929 finally ended widespread Mexican immigration. By the time of the crash, most Mexicans who remained lived in the agricultural peripheries or scattered urban barrios. / Dissertation/Thesis / Ph.D. History 2012

abstract: Many studies over the past two decades examined the link between climate patterns and discharge, but few have attempted to study the effects of the El Niño Southern Oscillation (ENSO) on localized and watershed specific processes such as nutrient loading in the Southwestern United States. The Multivariate ENSO Index (MEI) is used to describe the state of the ENSO, with positive (negative) values referring to an El Niño condition (La Niña condition). This study examined the connection between the MEI and precipitation, discharge, and total nitrogen (TN) and total phosphorus (TP) concentrations in the Upper Salt River Watershed in Arizona. Unrestricted regression models (UMs) and restricted regression models (RMs) were used to investigate the relationship between the discharges in Tonto Creek and the Salt River as functions of the magnitude of the MEI, precipitation, and season (winter/summer). The results suggest that in addition to precipitation, the MEI/season relationship is an important factor for predicting discharge. Additionally, high discharge events were associated with high magnitude ENSO events, both El Niño and La Niña. An UM including discharge and season, and a RM (restricting the seasonal factor to zero), were applied to TN and TP concentrations in the Salt River. Discharge and seasonality were significant factors describing the variability in TN in the Salt River while discharge alone was the significant factor describing TP. TN and TP in Roosevelt Lake were evaluated as functions of both discharge and MEI. Some significant correlations were found but internal nutrient cycling as well as seasonal stratification of the water column of the lake likely masks the true relationships. Based on these results, the MEI is a useful predictor of discharge, as well as nutrient loading in the Salt River Watershed through the Salt River and Tonto Creek. A predictive model investigating the effect of ENSO on nutrient loading through discharge can illustrate the effects of large scale climate patterns on smaller systems. / Dissertation/Thesis / M.S. Biology 2012