• Uncertainty in Sediment Yield from a Semi-Arid Watershed

      Smith, J. M.; Fogel, M.; Duckstein, L.; Systems & Industrial Engineering, University of Arizona, Tucson, Arizona 85721; Watershed Management and Systems & Industrial Engineering, University of Arizona, Tucson, Arizona 85721 (Arizona-Nevada Academy of Science, 1974-04-20)
      The paper presents a stochastic model for the prediction of sediment yield in a semi -arid watershed based on rainfall data and watershed characteristics. Uncertainty stems from each of the random variables used in the model, namely, rainfall amount, storm duration, runoff, and peak flow. Soil Conservation Service formulas are used to compute the runoff and peak flow components of the Universal Soil Loss Equation. A transformation of random variables is used to obtain the distribution function of sediment yield from the joint distribution of rainfall amount and storm duration. The model has applications in the planning of reservoirs and dams where the effective lifetime of the facility may be evaluated in terms of storage capacity as well as the effects of land management on the watershed. Experimental data from the Atterbury watershed is used to calibrate the model and to evaluate uncertainties associated with our uncertain knowledge of the parameters of the joint distribution of rainfall and storm duration.
    • United States-Mexico Water Agreements and Related Water Use in Mexicali Valley: A Summary

      DeCook, K. J.; Water Resources Research Center, The University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
      A summary is given of interrelated, technical and institutional events concerning the Colorado River which took place between the United States and Mexico from 1849 to 1974 with emphasis on the 1961-1974 period. Until the treaty of 1944, Mexico had had no guarantee of a specific annual quantity of water, but in the years after 1945, when a guarantee of 1.5 million acre-feet per year was established, more than that amount was available for use. Salinity problems arose, and in 1965 an agreement for a 5-year plan for alleviating the technical and political difficulties surrounding the salinity question was made. In 1973 it was agreed that the United States would build, within approximately 5 years, a facility for desalting the saline drainage water entering Mexico. Fulfillment of the technical provisions for this agreement requires, in any event, the timely provision of federal funds to construct and operate the physical works. The several states should receive assurance that their rights and those of their respective water users will not be impaired within the legal operation of the agreement.
    • Using Linear Regression in Hydrological Design

      Peterson, G. D.; Davis, D. R.; Weber, J.; Department of Systems and Industrial Engineering, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
    • Water Resource Alternatives for Power Generation in Arizona

      Smith, Stephen E.; DeCook, K. James; Fazzolare, Rocco A.; Nuclear Engineering, University of Arizona, Tucson; Water Resources Research Center, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
      An examination of potential water sources for power plant cooling in Arizona is presented along with information pertinent to Arizona's future water needs relative to electrical usage growth. It has been projected that Arizona's peak electrical power demands in 1980 and 1990 will exceed that of 1970 by some 5000 megawatts and 16000 megawatts of electricity respectively. At present, the bulk of the electrical energy generated in the western states originates at hydroelectric installations. Utilization of nuclear reactors for power generation requires a larger amount of cooling water than is required for a comparable fossil-fueled plant. It is suggested that the utilization of reclaimed wastewater for cooling purposes is a viable and attractive alternative to groundwater pumpage from both economic and ecological standpoints. Savings arise from conservation of fuel normally required for well pumps, costs of well construction are not required, quantities of fresh water should be released for consumption by alternate users, and a previously unused resource would be effectively recycled.
    • Water Resources of the Inner Basin of San Francisco Volcano, Coconino County, Arizona

      Montgomery, E. L.; DeWitt, R. H.; Northern Arizona University; City of Flagstaff Water Department (Arizona-Nevada Academy of Science, 1974-04-20)
      The inner basin is a collapse and erosional feature in San Francisco Mountain, an extinct volcano of late Cenozoic age, which lies approximately eight miles north of flagstaff, Arizona. The main aquifer's coefficient of transmissibility is approximately 14,000 gallons per day per foot and the storage coefficient was 0.08. Aquifer boundaries increased rates of drawdown of water levels in the inner basin well field. Inner basin springs which issue from perched reservoirs are not affected by pumpage of inner basin wells. Recharge is greater than the average yield from springs and wells in the basin which has an average of 8,000 acre-feet of water in storage in the principal aquifer. A large amount of water is lost from the inner basin aquifer system via leakage into underlying fractured volcanic rocks. It is believed that a part of this water could be intercepted by pumpage from a well constructed in the interior valley.
    • Water Resources Research on Forest and Rangelands in Arizona (invited)

      Hibbert, Alden R. (Arizona-Nevada Academy of Science, 1974-04-20)
      A progressive and coordinated effort is underway to provide a sound technical basis for managing water resources on forest and rangelands in the Southwest. An in-house Forest Service (USDA) research program including pilot testing and economic evaluations of multiple-use alternatives provides information necessary for this purpose. Demands for other goods and services also are increasing on these lands in the face of a burgeoning population. homeseekers, vacationers, and recreationists seek a variety of recreational. experiences that require open space and a relatively undisturbed environment. Frequently these uses conflict, and the combined pressure from too many activities can damage the environment. A new research effort has been organized in the central and southern Rocky Mountain Region to cope with these problems. Nine Western universities including Northern Arizona University, Arizona State University, and University of Arizona have joined forces with the Rocky Mountain Forest and Range Experiment Station to form the Eisenhower Consortium for Western Environmental Forestry Research. Simply stated, the consortium seeks to better our understanding of the relationships between man and his open-space environment in order that its quality might be maintained.