• Comments on Report of Tucson Community Goals Conference

      Kassander, A. Richard, Jr.; Water Resources Research Center, University of Arizona (2014-03-22)
    • Water Resources Research Center, The University of Arizona, Artificial Recharge Projects

      Water Resources Research Center, University of Arizona (Tucson, AZ), 2014-03-21
    • Potential of Wastewater for Commercial Barley Production

      Day, A. D.; McFadyen, J. A.; Tucker, T. C.; Cluff, C. B.; Department of Plant Sciences, University of Arizona; Department of Plant Sciences, University of Arizona; Department of Soils, Water, and Engineering, University of Arizona; Water Resources Research Center, University of Arizona (2014-03-21)
      Experiments were conducted in southern Arizona to investigate the effects of irrigation with pump water and a pump water-wastewater mixture on barley (Hordium vulgare L.) growth, grain yield, and grain quality; soil properties; and irrigation water quality. In 1974 and 1975, on small plot research, barley irrigated with a 50:50 mixture of pump water and wastewater significantly exceeded barley irrigated with pump water alone in plant height, number of heads per unit area, number of seeds per head, seed weight, grain yield, and straw yield. In large field studies conducted from 1970 through 1977, barley irrigated with the mixture had taller plants, more lodging, lower grain volume-weights and higher grain yields than barley irrigated with pump water alone. Soils irrigated with both types of irrigation water had similar pH. Soluble salts (ECx103), exchangeable sodium percentage, nitrate-nitrogen, and extractable phosphorus were significantly higher in soils irrigated with the pump water-wastewater mixture than in soils irrigated with pump water. Water quality analyses showed that the pump water-wastewater mixture had lower total soluble salts, lower nitrate-nitrogen, and higher phosphorus levels than pump water alone.
    • The Effect of an Intensive Summer Thunderstorm on a Semiarid Urbanized Watershed

      Boyer, D. G.; DeCook, K. J.; Water Resources Research Center, University of Arizona; Water Resources Research Center, University of Arizona (2014-03-21)
      The University of Arizona Atterbury Experimental Watershed, located southeast of Tucson, Arizona has been instrumented for precipitation and runoff measurements since 1956. Early on the afternoon of July 16, 1975 an intense convective thunderstorm produced more than three inches of rainfall in less than 50 minutes as recorded in several rain gages located in the middle of one 8.1 square-mile desert subwatershed. Storm runoff from this rural subwatershed and an adjacent recently urbanized subwatershed filled the newly finished Lakeside Reservoir and topped the concrete flood spillway with a peak of greater than 3000 cfs, the greatest flow since monitoring began. An analysis of storm characteristics, along with previously available data from local urbanized watersheds, allows speculation on the effect of such an intensive storm in a highly urbanized.area.
    • An Outline for a Proposal for a Study of Retired Farmland Management in Urbanizing Semiarid Environments

      Cluff, C. B.; DeCook, K. J.; Jordan, G. L.; Dutt, G. R.; Day, A. D.; Mielke, E. A.; Water Resources Research Center, University of Arizona; Water Resources Research Center, University of Arizona; Department of Range Management, University of Arizona; Department of Soil, Water & Engineering, University of Arizona; et al. (2014-03-21)
    • Ground-Water Recharge from Urban Runoff and Irrigation Returns

      DeCook, K. J.; Wilson, L. G.; Water Resources Research Center; Water Resources Research Center (2014-03-19)
      Preliminary information on urban runoff from selected small watersheds in the Tucson area indicates that average annual runoff from the urbanized areas is more than four times as much as that of a comparable undeveloped desert area, and may be ten times as much in some individual years. The urban runoff contains relatively high concentrations of bacterial loading and dissolved organics; although it is not now known to be a seriously hazardous source of pollutants in ground water, urban runoff should be monitored with increasing urban growth, especially for content of organics, microorganisms, and trace metals. Additional study also should be given to the travel-time regime of runoff from the small tributary urban watershed to the major stream channels where recharge mainly occurs. Deep percolation from irrigation return flows was evaluated during a one -year study for the U.S. Geological Survey's "Southwest Alluvial Basin, Regional Aquifer System Assessment Program". Objectives of the study included (1) identifying sources of recharge information, (2) collecting and summarizing available recharge information, (3) identifying methods for interbasin transference of recharge values, (4) characterizing deep percolation models, and (5) itemizing methods for overcoming data gaps. Apparently there is a difference in opinion among irrigation experts on the extent to which recharge from deep percolation occurs. One reason for the difference of opinion is that field measurements of the flux and velocity components of deep percolation through the vadose zone are scarce, particularly for deep alluvial basins. Similarly, there is a need for a simple, theoretically-based model of deep percolation /recharge. Many of the data deficiencies could be overcome by conducting lumped and site-specific field studies. Such studies, although expensive, would be timely in light of the current interest in ground-water management.
    • Asphalt-Crumb Rubber Waterproofing Membrane

      Frobel, Ronald K.; Jimenez, R. A.; Cluff, C. Brent; Morris, Gene R.; Water Resources Research Center, University of Arizona; Civil Engineering Department, University of Arizona; Water Resources Research Center, University of Arizona; Arizona Department of Transportation (2014-03-19)
      This report is concerned with laboratory testing and field investigations of a water seepage barrier consisting of asphalt cement and reclaimed crumb-rubber tire peel. The test methods that were utilized and evaluated included the following: water vapor transmission (ASTM E96 -72, Procedure BW), water absorption (ASTM 570-72), ductility (ASTM D113-74), viscosity, toughness, and brittleness /impact resistance (ASTM 0994-72). The test results showed that the asphalt-rubber as a membrane is relatively impermeable and absorbs an insignificant amount of water. The crumb rubber effectively increases the viscosity of the asphalt cement while decreasing the ductility value. The asphalt-rubber combination exhibits a tough, impact resistant membrane with excellent waterproofing properties.
    • An Evolutionary Perspective on Social Values

      Lord, William B.; Water Resources Research Center (2013-12-30)
      The incorporation of social and environmental objectives in water resources planning and management has been, and will continue to be, the result of several evolutionary processes. The most general of these processes is the evolution of rational-analytic thinking as a form of problem solving behavior. A second evolutionary process is the development of institutional and analytical procedures for making public decisions. The most specific process is the evolution of federal water resources planning procedures in the United States. These processes are examined, the changing institutional environment within which water resources planning and management occurs is characterized, and implications are drawn for future incorporation of social and environmental objectives.
    • Jojoba Water-Harvesting Agrisystem Experiment, Papago Indian Reservation, Sells, Arizona

      Cluff, C. Brent; Water Resources Research Center (University of Arizona (Tucson, AZ), 2013-12-30)
    • Crop Consumptive Use Simulation Using a Water Harvesting Model

      Risley, John C.; Cluff, C. Brent; School of Renewable Natural Resources; Water Resources Research Center (2013-12-06)
      A Compartmented Reservoir Operation Program, CROP84, is a computer program developed, by C. B. Cluff (1977), as a tool for optimizing the design dimensions of water harvesting agriculture systems. This model is used in conjunction with a rainfall /runoff model called RAMOD. The objective of the research was to compare the actual and the simulated values of seasonal irrigation and consumptive use of four crops: wheat, sorghum, cotton, and grapes. After repeated simulations structural improvements were made in the soil moisture accounting routine of CROP84. These improvements were in the equations that calculated the rate of root growth, the soil moisture depletion fraction and actual evapotranspiration. In the final simulation, the percentage difference for crop consumptive use calculated from the actual data and the simulation was +2.6 % for sorghum, -2.4 % for grapes, +2.0 % for wheat, and -8.8 % for cotton.
    • Future Outlooks for Water Conservation in Arizona

      Resnick, Sol; Water Resources Research Center (2013-11-14)
    • Groundwater Pollution Monitoring Case Studies

      Wilson, L. G.; Water Resources Research Center (Water Resources Research Center, University of Arizona (Tucson, AZ), 2013-11-14)
      Investigators who were closely associated with five groundwater monitoring programs were asked to critically examine their studies as a guide to others involved in similar projects. The particular question to be answered was, "What monitoring techniques should have or could have been implemented?" given that time and money were not constraints. The case studies involved contamination of aquifers from oil field brine disposal, plating waste disposal, landfill leachate, nitrate from multiple sources, and recharge from an oxidation pond. Among the general recommendations of the investigators, resulting from the process of critical evaluation of their associated projects, were the following: establish interdisciplinary committees to set up the monitoring program; maximize the density of well network; use alternative methods to wells; completely analyze the samples, including heavy metals; thoroughly examine the hydrogeology of the problem site; use tracers; develop predictive computer models of the flow system; monitor in the zone of aeration, where applicable; develop innovative methodologies; and continue monitoring until the problem is thoroughly quantified.
    • Low-Cost Photovoltaic Power and/or Thermal Energy Using Intermediate Solar Concentrators

      NOW AVAILABLE- low-cost photovoltaic power and /or thermal energy using intermediate concentrators. This patented technology developed and tested at the University of Arizona uses a unique concentrator made of inexpensive glass back-surfaced mirrors mounted on parabolas molded out of foamed plastic. The use of back-surfaced mirrors instead of aluminum or other materials assures a long life of high reflectivity. Each mirror segment is aligned using a laser which optimizes efficiency.
    • Preliminary Report on W.I.F.S.

      Introduction: Wax Impregnated Foam System was designed to produce on a mass-production level, paraffin impregnated expanded polystyrene sheets for evaporation suppression. Preliminary results under small-scale laboratory conditions indicated sufficient impregnation under low pressure conditions that would make a large-scale system feasible.
    • Final Report on An Evaluation of Annual Heat Storage of Solar Energy for Arizona Subdivisions Using an Azimuth Tracking Floating Collector

      Cluff, C. Brent; Kinney, Robert B.; Eskandani, F.; Solar Energy Research Facility, Engineering Experiment Station (Solar Energy Research Facility, Engineering Experiment Station, University of Arizona (Tucson, AZ), 2013-07-24)
    • Arizona's Changing Rivers: How People Have Affected the Rivers

      Tellman, Barbara; Yarde, Richard; Wallace, Mary G.; Water Resources Research Center; Water Resources Research Center; Water Resources Research Center (Water Resources Research Center, University of Arizona (Tucson, AZ), 1997-03)
    • Water Harvesting Potential Dodoma & Shinyanga Districts Tanzania

      Cluff, C. Brent; Water Resources Research Center (1993-07)
      Introduction: Water Harvesting Systems is an appropriate technology method of meeting the domestic water supply in the Dodoma and Shinyanga areas. It is important that the most cost effective methods be utilized. The most apparent methods are first described and then "fitted" to the Dodoma and Shinyanga areas using a rainfall /runoff computer model. Before the model can be used it was important to visit the locations where water is needed. This was accomplished during a field trip while the consultant was visiting Tanzania from March 6 to March 20, 1993. The trip to the Dodoma started on March 9, 1993 where we stayed until March 11, after which we drove on the Shinyanga, arriving on March 13. We stayed in Shinyanga for 3 days before leaving for Mwanza where we returned by plane to Dar Es Salaam on the morning of March 17.
    • Photovoltaic/District-Heated and Desiccant-Cooled Solar Powered Community Using an Insulated Pond

      Cluff, C. Brent; Water Resources Research Center (1991-08)
      In 1987 Arizona's governor announced a goal of constructing a solar powered community that would produce as much energy from the sun as it consumed. As a part of that program the use of a water cooled photovoltaic system evolved. The thermal energy would be utilized in homes with a district heating and desiccant cooling system. Thermal powered desiccant cooling was selected because it required water with relatively moderate temperatures, 140-1600F, that could be easily transported in insulated low-cost plastic pipe. Three ASK Corp. desiccant cooling/heating units have been successfully operated in the Phoenix area on a 5000 sq ft solar-powered residence since October, 1985. There also are photovoltaic/water cooled intermediate concentrators commercially available that have been thoroughly tested through different Department of Energy programs. This study describes the use of a computer to design a hybrid photovoltaic/thermal system providing heat to a district heating and desiccant cooling system for a 24 home subdivision in the Phoenix area of Arizona. Excess thermal energy is stored in an insulated pond. The gunite coated foam cover of the pond served as a tracking base for the concentrating solar collectors.
    • Slow Sand/Nanofiltration of Surface Water

      Cluff, C. Brent; Gerba, Charles P.; Amy, Gary L.; University of Arizona; University of Arizona; University of Colorado, Boulder (1990-08-06)
      Introduction: Through the studies published in Drinking Water and Health (1977) the nation has become more aware of the carcinogenic nature of the byproducts of disinfection such as trihalomethanes. Trihalomethanes are formed when the disinfectant chlorine reacts with the precursors, humic and fluvic acids that are naturally occuring in all surface water. The Environmental Protection Agency (EPA) has set a minimum contaminent level of 100 ppb on THM's that many in the health agencies feel need to be lowered. The problem is that when the MCL's are lowered utilities will be enclined to chlorimines and chloride dioxide which have been found to be mutagenic. Drinking Water and Health (1987) found the Suggested No-Adverse Response Levels (SNARLs) for chioramines for a child is 0.166 ppm, for an adult it is 0.581. The SNARL for chlorine dioxide is 0.06 ppm for a child and 0.210 ppm for an adult. These levels for utilities are virtually impossible to maintain and still have a residual at the end of the system.