Now showing items 14578-14597 of 14781

    • Water budget computer model to investigate the effectiveness of evaporation control on Thompson Reservoir, Santa Catalina Island, California

      Lozier, William Blaine.; Evans, Daniel D.; Fogel, Martin M.; Sorooshian, Soroosh (The University of Arizona., 1984)
      Evaporation control is investigated as a partial solution to Santa Catalina Island's historical problem of an inadequate freshwater supply. The objective is to determine what effect an evaporation cover would have on increasing the safe yield of the major water supply reservoir, Thompson Reservoir. A water budget computer model of the reservoir/aquifer system is developed. The model is capable of recreating the reservoir elevation history since November, 1966. Domestic use is increased to determine the safe yield of the system based on the period 1966-1983. The calculated safe yield of 406 acre-feet is not realistic considering that more extreme drought conditions have occurred prior to 1966. This indicates that the actual safe yield of the reservoir is somewhat lower. Evaporation control runs were made with cover areas of 5, 10, 15, 20 and 25 acres. It was found that these covers are effective in increasing the safe yield by as much as 70 acre-feet per year. It is concluded that evaporation control on Thompson Reservoir would be an effective means of increasing Catalina's freshwater supply.
    • Water content of unsaturated, fractured, crystalline rocks from electrical resistivity and neutron logging

      Andrews, John W.,1955-; Evans, Daniel D. (The University of Arizona., 1983)
      Changes in the water content of unsaturated, fractured, crystalline rocks were measured with electrical resistivity and neutron techniques. Boreholes drilled into a quartz monzonite near Lochiel, Arizona were logged periodically from October 1982 through August 1983; and a borehole drilled into a dacitic ash-flow tuff near Superior, Arizona was logged periodically from March 1983 through August 1983. The boreholes, drilled from existing mine tunnels, were situated above the water table and six meters below the surface at the Lochiel site and 80 meters below the surface at the Superior site. The resistivity and neutron data indicate changes in the water content of the quartz monzonite were in response to surface precipitation. The response time was approximately six weeks when the overburden was initially dry. The resistivity and neutron data also correlate with water level data measured in a nearby saturated borehole. Similar trends were not observed at the Superior site. The resistivity and neutron data from Superior indicate the water content of the dacitic ash-flow tuff did not change during this study.
    • Water flow and transport through unsaturated discrete fractures in welded tuff

      Sully, Michael; Myers, Kevin Christopher, 1965- (The University of Arizona., 1989)
      Porous plates delivered calcium chloride at a negative potential to the top of blocks of partially welded (20.1 x 20.1 x 66.6 cm) and densely welded (30.1 x 20.1 x 48.1 cm) tuff with discrete fractures. During infiltration, flux increased through the partially welded block's fracture as the applied suction was lowered to 2.3 cm. The wetting front advanced 66.6 cm in 239 days. Chloride concentration and temporal moments from five tracer tests with 0 to 5 cm of applied suction indicated that preferential fracture flow occurred. Displacement transducer data reflect a decrease in fracture aperture at several months prior to but not during tracer tests. Fracture transmissivities decreased an order of magnitude (6.4 x 10⁻⁹ to 4.2 x 10⁻¹⁰ M²/s) as the applied suction increased from 0 to 5 cm while the tensiometer data indicated a suction of about 20 cm of water within the fracture and matrix. Highest during infiltration to an initially dry block, inflow losses of 3 to 44 percent due to evaporation are the greatest source of error for the constant potential method used.
    • Water flow through variably saturated fractured tuff : a laboratory study

      Haldeman, William Robert,1958-; Evans, Daniel D. (The University of Arizona., 1988)
      Laboratory techniques were developed that allow concurrent measurement of unsaturated matrix hydraulic conductivity and fracture transmissivity of fractured rock blocks. Two blocks of Apache Leap tuff containing natural fractures were removed from a site near Superior, Arizona, shaped into rectangular prisms, and instrumented in the laboratory. Porous ceramic plates provided solution to the top of the test blocks at regulated pressures. Infiltration tests were performed on both test blocks. Steady-state flow testing of the saturated first block allowed the determination of matrix hydraulic conductivity and fracture transmissivity. Fifteen cm of suction were applied to the top of the second block throughout an imbibition test. Analysis of infiltration into that block indicates that fracture flow at the low compressive stress applied during the test was minimal and matrix hydraulic conductivity at 15 cm of suction was an order of magnitude less than the saturated matrix hydraulic conductivity of the first block.
    • Water in Tucson: Policy, Planning, and Public Involvement

      Hathaway, Pamela Lynne.; Ingram, Helen M.; Brickler, Stanley K.; Wilkin, Donovan C.; Gregg, R. Frank (The University of Arizona., 1984)
      This paper describes and assesses the policies, planning agencies, and citizen advisory committees which are involved in water resource decision making in the Tucson basin. Shifting priorities in basin water uses are traced by reviewing four events and trends. This review, together with a description of existing policies and planning agencies, provides the basis for assessing the status and potential for public involvement in water resource decision making. The influence of the citizens advisory committees on water resource decision making depends on the relationship among an agency, a committee, and the general public. If citizens advisory committees are to address controversial issues, such as those surrounding the priorities of water use in the basin, a link between community education and political participation is necessary.
    • Water infiltration and percolation at the University of Arizona radioactive waste burial site, Pinal County, Arizona

      Salvetti, Joseph Peter.; Dutt, Gordon R. (The University of Arizona., 1984)
      The University of Arizona produces different types of radioactively contaminated waste. It is shipped to a burial site located on the Oracle Agricultural Center in Pinal County, Arizona and disposed of in shallow pits. This study dealt with water movement at the disposal site. Monitoring of water movement through young pits was accomplished with a neutron probe. It was found that due to slumping and cracking of the pit cap, the younger pits were very susceptible to greater than normal water infiltration. Further data were gathered around the older pits by deep soil sampling for tritium activity. Water fluxes and travel times to the major aquifer were calculated from these data. Estimates of travel times range from 40 to 230,000 years to reach the principal aquifer at 150 m.
    • Water intake at the atmosphere-earth interface in a fractured rock system near Patagonia, Arizona

      Kilbury, Richard Kenneth.; Evans, Daniel D.; Simpson, Eugene S.; Sorooshian, Soroosh (The University of Arizona., 1984)
      Surface water intake into a fractured rock system provides water for downward percolation and transport of contaminants. This study involves the measurement and simulation of water intake across the atmosphere-earth boundary, for an exposed densely welded tuff, near Patagonia, Arizona. Water and air intake rates were measured using a fractured rock infiltrometer (FRI). Calculated fracture apertures using water and air agreed Well. Fracture apertures determined using water range from 1.0 to 33.7 pm and are shown to be log-normally distributed. Rainfall events are reconstructed in a model to simulate flow across the atmosphere-earth boundary. As an example a ten-year simulation resulted in a mean annual intake rate of 2.1 millimeters (mm), and is shown to be more dependent on storm duration than intensity. Developed methods provide a means of characterizing water intake rates into a fractured rock surface based on rainfall characteristics.
    • Water Law and policy in the Sonoita Creek Basin

      Ince, Simon; Blomgren, Nathan Frederick (The University of Arizona., 1999)
      The Sonoita Creek Basin covers 270 square miles in southeastern Arizona, Santa Cruz County. The city of Patagonia is the main population center in the watershed with about 1000 residents. There are numerous surface water rights and applications to appropriate the waters of Sonoita Creek, which flows perennially from the city of Patagonia to Patagonia Lake. The relatively small flows of the Creek are divided among numerous users, including ranching, irrigation, municipal water supply, domestic water supply, recreation and wildlife. The separation of groundwater and surface water in Arizona water law makes the legal determination of rights difficult in many circumstances. The eventual status of many vested water rights is unknown because the law is being written at the time of publication. A Court decision on a method to identify wells that are pumping appropriable water is pending, after which the Gila River Adjudication will examine all water rights in the watershed and decide on their legitimacy. Water quality regulation in the Sonoita Creek Basin is limited to drinking water and effluent standards, and monitoring of abandoned mines. The determination of the source of water supply for Patagonia will dictate their treatment requirements. The struggle to replace an aging wastewater treatment plant is ongoing. High acidity and metal content in waters percolating through abandoned mines continues to be monitored and the threat to downstream targets assessed.
    • Water management and crop selection for intensive gardens in arid regions

      Rude, Peter Heinz,1961-; Matlock, W. Gerald (The University of Arizona., 1988)
      Agricultural development projects in arid regions are hampered by lack of knowledge surrounding the efficient use of water and an understanding of the indigenous people. A method, using computer models, is presented for analyzing water management and selecting a crop mix for intensive gardens in arid regions. The crop mix is constrained by land and water availability and the nutritional requirements of a family. Model results indicate that an intensive garden grown during the entire year in Tucson, Arizona (annual precipitation of 285 mm), would require approximately 140 cm of water per unit area of land with an irrigation application efficiency of 73%. Results are based on irrigating the entire garden using the water requirement of the crop which has the highest demand for water since the previous irrigation. A table showing the nutritional content of five crops per unit of water applied during the growing season is presented.
    • Water management and the kinship system: An investigation of the interface between resource management and society in the developing world

      Ince, Simon; Audrey, Anne, 1957- (The University of Arizona., 1990)
      Patterns of water resource management are affected by the social structures of indigenous societies. The social structures of many indigenous groups, and in particular tribal groups, are kin-based. Water resource development projects which focus on kin-based societies may be affected by the characteristics of a society's kinship system. Three case studies of irrigating tribal societies were analyzed to determine the effects of kinship systems on water management. Results of the analysis indicate that in these societies water management was conducted under the auspices of kinship systems and according to norms consistent with kinship relationships. Each society's kinship system adapted as necessary to the environmental and physical constraints of irrigation. Following major political and water resource development changes, the role of kinship systems tended to decrease, but continued to influence patterns of water resource use.
    • Water management for agriculture in Senegal

      Thiouf, Alassane,1959-; Matlock, William G.; Hart, W. E.; Slack, Donald C.; Yitayew, Muluneh (The University of Arizona., 1987)
      Water problems in the Sahel region have lead to a study of water management in one country of the area, Senegal. Farming systems, human resources, and livestock production of the country have been analysed. Natural resources, water, soil, topography, and vegetation have also been studied. The study of the different resource shows the potential of improvement in water management. A specific location in Senegal, Kedougou, is chosen and a water management pilot project is designed. The Gambia river and rainfall are the main sources of water for the project. The project is used for different purposes among which are agricultural production, research, and economic improvement. The project is suitable technically, and social, political and economic environments are favorable. The pilot project demonstrates the adequacy of the technologies used for the project. A preliminary estimation of the costs gives an acceptable financial input for such a system.
    • Water management for the area downstream from the Imperial Dam on the Colorado River.

      Gordon, Yoram,1928-; Evans, Daniel D.; Kelso, M. M.; Maddock, T. (The University of Arizona., 1968)
      The Colorado River is the major supplier of water in the area of the lower Colorado below Imperial Dam. In this area the water is used in the United States -- by the states of Arizona and California -- and also in the Republic of Mexico. The water of the Colorado River is divided in accordance with various agreements. The Colorado River Compact guarantees the delivery of water to the Lower Basin States. The Boulder Canyon Project Act provides for the division of the water among these states. The Treaty of 1944 stipulates the quantity of water which must be delivered to Mexico. It now seems likely that there will be a shortage of water in this area within the next thirty years. On the other hand, water of poor quality flows abundantly in the drain canals. In fact, the discharge of the drainage water into the river channel is the principal factor contributing to the deterioration of the quality of the Colorado River. The increased salinity of the river water creates local as well as international problems. Further comprehensive study is needed in order to evaluate the alternative solutions to these problems.
    • Water management of short-season high-density cotton

      Mohammed, Robert Ali,1945-; Fangmeier, Delmar D. (The University of Arizona., 1975)
      Water management of short-season, high-density cotton was studied for three seasons (1972, 1973 and 1974). Various irrigation schedules and nitrogen fertilizer application rates were examined. Data on amounts of water applied, yield, boll and fiber properties, soil nitrate levels and cotton petiole nitrate levels were collected. Cotton was planted on 40-inch beds with two plant rows per bed 12 inches apart. For 1972, two varieties were planted, Anderson- Clayton 1764 and Deltapine 16; the plant population was 60,000 plants per acre. Deltapine 16 was the only variety planted in 1973 and 1974 with plant populations of 50,000 and 60,000 plants per acre, respectively. The 1972 experiment showed that Deltapine 16 was better suited to the short-season, high-density cotton production system than Anderson-Clayton 1764. In 1973 and 1974, experiments indicated that available soil moisture depletion should not exceed 50-55 percent. Also, criteria (based on available soil moisture) of when to irrigate should not be varied throughout the season. Results suggest that yields can be maintained with early irrigation termination if soil moisture, before irrigation, is kept at a higher level than is the normal practice. Application of 100 pounds of N per acre seemed to adequately meet the crop's needs for the season.
    • Water movement in nonisothermal tuff

      Davies, Bill Edward,1958-; Evans, D. D. (The University of Arizona., 1987)
      Water movement within three unsaturated welded tuff cores was studied in response to imposed thermal gradients of approximately 5°C/cm. Bulk density and initial, transient and final water content distributions were determined each 1-cm along the cores with gamma attenuation methods. Temperatures within the cores were measured by thermocouples embedded 1.5 cm into the rock cores. Liquid return flow toward the heat source was shown by the initial and final distributions of iodide. These experiments indicated that a countercurrent of water vapor driven away from a heat source and subsequent liquid return flow can be established when a thermal gradient is present within sealed porous rock cores. A field heating experiment was also performed in a densely-welded tuff formation. At a position 0.89 meters from a 1500W heat source, the temperature increased 11.1°C and the potential decreased approximately 9 bars after heating for 94 hours.
    • Water movement, structure and physiology in mung bean (Vigna radiata L.) leaves

      Matsuda, Kaoru; Parker, Beverly Jean, 1944- (The University of Arizona., 1992)
      Eight-day-old mung bean seedlings (Vigna radiata L.) grown in hydropondic medium were osmotically stressed by exposing roots to increasing concentrations of NaCl up to 4 bars. They were transferred after 16 to 18 hours to a similar solution containing tritiated water (THO). Periodic samples were taken of water transpiring from the leaves and of tissue water obtained from the same leaves, frozen and ground; specific radioactivity was determined by a scintillation counter. Proportional to increasing stress, the labelling of tissue water was increasingly delayed, the time for equilibration of the specific radioactivity in the two fractions lengthened, and equilibration occurred at higher concentrations of THO. Thus stress causes transpirational water to be increasingly restricted to extra-cellular pathways. Further investigations of stomatal function by leaf surface, of anatomy and of growth patterns were unsuccessful in finding an explanation for this behavior but did reveal a transpirational circadian rhythm and a continual layer of (air?) space between the palisade and spongy mesophyll, the latter organized into two compact rows.
    • Water pollution in an arid urban environment, Tucson, Arizona

      Hansen, Gary Bruce (The University of Arizona., 1979)
    • Water pollution in an arid urban environment, Tucson, Arizona

      Hansen, Gary Bruce.; Evans, Daniel D. (The University of Arizona., 1979)
      The scarcity of water resources in many of the arid urban areas of the United States has created a situation in which a continuing and increasing amount of concern is directed toward water pollution control and wastewater reuse. The Tucson, Arizona, urban area is representative of this trend. Municipal wastewater effluent, previously disregarded, is now beginning to be utilized as a valuable water resource. It is the most obvious wastewater source. There are, however, a number of other sources of polluted water which should be investigated to determine their impact on the scarce water resources of the arid urban area. These pollutant sources in the Tucson area include urban stormwater runoff, landfill leachate, on-site treatment systems, and construction activities. Within this study, each of these pollution sources is analyzed for quantity, quality, and location of pollutant. The pollution problem and the existing pollution management system for each area are assessed. In addition, some basic recommendations for future management of these problem sources are presented. The study is designed to fit into a comprehensive urban planning structure and suggests areas for future concern and increased water resource management as dictated by the unique arid climate and water needs of the Tucson urban area.
    • Water purification by forced-flow electrophoresis

      Cooper, Frederick Christian, 1940- (The University of Arizona., 1964)
    • Water purification by forced-flow electrophoresis

      Cooper, Frederick Christian, 1940-; Mees, Quentin M. (The University of Arizona., 1964)
    • Water quality analyses of Sabino Creek in the Summerhaven-Marshall Gulch area

      Patterson, Glenn Gilman, 1951- (The University of Arizona., 1977)