• Aerial Snowpack Mapping

      Warksow, William L.; Salt River Project, Phoenix, Arizona (Arizona-Nevada Academy of Science, 1975-04-12)
      Arizona's continued growth and development depends upon sound management of water resources, especially melted snow which is the primary source of water for the 1.1. Million residents of Maricopa county. The method for snowpack information gathering practiced by watershed specialists of the Salt River project in Arizona is described. The method is outlined, describing aircraft reconnaissance, direct enroute mapping of extent and depth of snowpack, and techniques for identifying ice and/or melt conditions. Under optimal conditions, this technique is considered more than acceptable for determining snowpack levels. Limitations of the technique result from the observer's tolerance of vertigo which can arise under flying conditions; cloud cover, which can reduce contrast and shadows thereby reducing accuracy of observation; and vegetation zones where density of plant matter screens much of the snow.
    • Antritranspirants as a Possible Alternative to the Eradication of Saltcedar Thickets

      Cunningham, Robert S.; Brooks, Kenneth N.; Thorud, David B.; School of Renewable Natural Resources, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1975-04-12)
      The response of saltcedar (Tamarix pentandra Pall.) to several antitranspirants was evaluated in laboratory, greenhouse and small -scale field studies using potted plants. Anti - transpirants may provide a treatment alternative to the eradication of saltcedar thickets for water salvage objectives. Transpiration rates were reduced by 23 to 44 percent for 7 to 20 days in the greenhouse, and by 18 to 32 percent for 2 to 8 days in the field. No serious damage to the plants was apparent. One of the most effective antitranspirants considered for a hypothetical saltcedar thicket and a hypothetical operational treatment program, based on estimated cost data, would result in reallocated water costing approximately 55 dollars per acre foot for a single treatment. About 19 acres of saltcedar thicket would have to be treated to provide one acre -foot of reallocated water in this case.
    • Application of Bayesian Decision Theory in Well Field Design

      Bostock, Charles A.; Davis, Donald R.; Department of Hydrology & Water Resources, University of Arizona, Tucson 85721; Hydrology & Water Resources, and Systems and Industrial Engineering, University of Arizona, Tucson 85721 (Arizona-Nevada Academy of Science, 1975-04-12)
      Bayesian decision theory is a method for comparing expected utilities of alternative actions given various possible states of nature. The method treats uncertainty as to the true state of nature by determining the expected utility of each action in terms of the probabilities of the various possible states. The decision rule is to choose the action having the best expected utility. This paper illustrates an application of Bayesian decision theory in a well field design problem where a decision had to be made regarding capacity-density combination for wells located in an extensive uniform grid. The uncertainty lay in anticipating the frequencies of transmissivity values among the wells.
    • Application of Direct Osmosis: Possibilities for Reclaiming Wellton-Mohawk Drainage Water

      Moody, C. D.; Kessler, J. O.; School of Renewable Resources, University of Arizona, Tucson; Department of Physics, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1975-04-12)
      A direct osmosis plant can reclaim twenty to thirty thousand acre feet of Wellton-Mohawk brackish drainage water using no more nitrogen fertilizer than is normally used in the Yuma, Coachella valley, Imperial Valley and the bordering Mexican areas. On a per-acre basis ammonium sulfate-driven direct osmosis can reclaim about one percent of the total irrigation requirement from 3000 ppm brackish water. In addition to the ammonium sulfate-driven direct osmosis efficiency, the by-product energy recovery of the manufacture of the fertilizer and the low technology inherent in direct osmosis processes make direct osmosis an appealing water reclaiming process.
    • The Application of Step-Drawdown Pumping Tests for Determining Well Losses in Consolidated Rock Aquifers

      Uhl, V. W., Jr.; Joshi, V. G.; Alpheus, A.; Sharma, G.; Hydrology and Water Resources, University of Arizona, Tucson, Arizona; Evangelical Lutheran Church Water Development Project, Getul, M.P., India (Arizona-Nevada Academy of Science, 1975-04-12)
      The concept of a step -drawdown test was first introduced by Jacob, and further modifications in the technique were made by Rorabaugh. Analysis of step -drawdown test data enables the quantification of the components of drawdown due to formation or aquifer loss, and due to well losses in a pumped well. This technique has been used to test approximately 100 wells that were drilled in crystalline and basalt formations in central India. Test data have been analyzed by Rorabaugh's method and by a graphical method, and the results of a number of tests are presented and discussed. Anomalies in the test analysis often proved helpful for interpreting aquifer irregularities. In general, the well loss constant decreases with an increase in specific capacity and the aquifer loss constant decreases with increasing transmissivity. Significant reductions in specific capacity during a step test occur in wells with high well losses. An attempt is made to quantify the well losses in a consolidated rock well, and a number of practical applications of step -drawdown tests are discussed.
    • Applications of Direct Osmosis: Design Characteristics for Hydration and Dehydration

      Kessler, J. O; Moody, C. D.; School of Renewable Resources, University of Arizona, Tucson; Department of Physics, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1975-04-12)
      In direct (normal, forward) osmosis water automatically flows through a semipermeable membrane from a "source" solution of low concentration to a "driving" solution with higher solute content. The process requires a membrane which is impermeable to the solutes; hydrostatic pressure differences are not directly involved and can be set equal to zero. In principle, direct osmosis is a low -technology, low-power consumption method for reducing the water volume of industrial effluents or liquid agricultural products, and for reclaiming brackish irrigation water. In the latter application the driving solution may utilize fertilizer as a solute; the source solution is drainage that contains harmful salt components. This type of operation has been experimentally demonstrated. This paper summarizes basic physical principles and introduces some quantitative design factors which must be understood on both a fundamental and on an applications level.
    • Applications of Finite Element and Computer Graphics Techniques in Aquifer Analysis

      O'Donnell, D. F.; Wilson, L. G.; Rasmussen, W. O.; Water Resources Research Center, The University of Arizona, Tucson; School of Renewable Natural Resources, The University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1975-04-12)
      Aquifer flow systems have been simulated by a variety of techniques. The results of these simulations can be presented in several ways. Of the approaches in modeling groundwater flow, the finite element method offers an advantage through its ease in approximating various boundary conditions. Graphic methods offer a means of simplifying data presentation. This study demonstrates the use of a finite element technique in modeling aquifer flow systems, and illustrates a 3-dimensional graphic approach when representing the results of the modeling.
    • The Arizona Water Resources Information System - 1975

      Winikka, Carl C.; Arizona Resources Information System, Department of Revenue, Phoenix, Arizona (Arizona-Nevada Academy of Science, 1975-04-12)
      The Arizona resources information system is designed to serve on going needs of the people of Arizona through state, federal and local agencies. The various land and water environmental organizations use the resource system for their research. The aris has prepared Arizona orthopotoquads, developed early land use classification systems, and evaluated electronic data processing graphical and analytical systems and many information systems.
    • Assessing Soil Moisture Remotely

      Reginato, Robert J.; Idso, Sherwood B.; Jackson, Ray D.; Agricultural Research Service, U.S. Department of Agriculture; ARS, USDA, U. S. Water Conservation Laboratory, Phoenix, Arizona 85040 (Arizona-Nevada Academy of Science, 1975-04-12)
      Space-age technology has produced tools which when turned to earthly pursuits can provide information on food and fiber production. Soil moisture has the potential for being remotely assessed, and three techniques for accomplishing this are under study. Two of the methods, reflectance and thermal, are sensitive to the conditions of the bare soil surface. The third technique, microwave emission, appears to have a good potential for assessing soil moisture with depth, because of its greater wavelength.
    • Assessing the Bare Soil Evaporation Via Surface Temperature Measurements

      Idso, Sherwood B.; Reginato, Robert J.; Jackson, Ray D.; Agricultural Research Service, U.S. Department of Agriculture; ARS, USDA, U. S. Water Conservation Laboratory, Phoenix, Arizona 85040 (Arizona-Nevada Academy of Science, 1975-04-12)
      Evaporation of water from bare soils is an important consideration in the scheduling of many farming operations in both irrigated and dryland agriculture. Accurate predictions of bare soil evaporation can serve as the basis for decisions to increase the acreage planted with a given crop. An alternative is presented to previous approaches to bare soil evaporation estimation by empirically correlating the ratio of daily totals of actual to potential evaporation and the amplitude of the diurnal surface soil temperature wave. Since evaporation is directly related to the surface soil water pressure, the soil thermal inertia technique might be capable of prescribing relative bare soil evaporation rates which, combined with potential evaporation calculations, could allow determination of actual evaporation rates over the entire range of soil drying.
    • Chemistry of Effervescing Groundwater from Municipal Wells, Flagstaff, Arizona

      Germ, John C.; Montgomery, Errol L.; Northern Arizona University, Flagstaff (Arizona-Nevada Academy of Science, 1975-04-12)
      Gas which effervesces from groundwater from Flagstaff's municipal wells is derived from dissolved atmospheric air. Groundwater from the Coconino aquifer at the flagstaff municipal wells is classified as calcium magnesium bicarbonate sulfate water and is similar to groundwater pumped from the Coconino aquifer by other wells in the flagstaff area. The source of the gas which effervesces from groundwater pumped by the municipal wells is believed to be air which is trapped in the Coconino aquifer during recharge.
    • Describing Snowpacks in Arizona Mixed Conifer Forests with a Storage-Duration Index

      Warren, Mark A.; Ffolliott, Peter F.; School of Renewable Natural Resources, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1975-04-12)
      The quantification of snowpacks in relation to inventory-prediction may be useful in the development of water yield improvement practices involving vegetation management in the mixed conifer forests in Arizona. While mixed conifer forests are relatively limited in extent in Arizona, the potential for water yield improvement by manipulation of snow storage through vegetation management may be high. Sample points on the north fork of Thomas Creek showed high initial snow storage followed by slow melt in association with low forest densities, low potential insolation values, and high elevation. Sample points exhibiting these conditions also possessed maximum storage-duration index values. Low initial snow storage followed by rapid melt was associated with high forest densities, high potential insolation values, and low elevations
    • Development and Testing of a Laser Rain Gage

      Ozment, Arnold D.; Arizona State University, Tempe, Arizona; Colorado State University, Fort Collins (Arizona-Nevada Academy of Science, 1975-04-12)
      Current catchment methods of measuring precipitation have several problems which affect their accuracy. The physical presence of the gage disturbs windflow patterns and reduces catch. Other errors of less significance arise from evaporation from the gage, and wetting of the gage. A method is described of measuring precipitation by scattering light from a beam by waterdrops. The sampling medium is a collimated beam from a helium-neon laser. The amount of light scattered is a function of the number and size of drops intercepting the beam.
    • Economic Adjustment to a New Irrigation Water Source: Pinal County, Arizona and the Central Arizona Project

      Boster, Mark A.; Martin, William E.; Department of Agricultural Economics, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1975-04-12)
      Pinal County is one of Arizona's largest farm and highest farm income areas. Agriculture there is completely dependent upon irrigation systems, with nearly all of the water supply pumped from underlying groundwater reservoirs. Delivery of central Arizona project water will not assure groundwater conservation at a one to one trade-off ratio. Most of the monetary benefits to agriculture derived from the project will be realized by Indian farmers. Cotton acreage will not be affected, but the acreage of small grains and alfalfa will increase. The increasing salinity of cap water should be of no concern to Pinal County farmers.
    • The Effect of Increasing the Organic Carbon Content of Sewage on Nitrogen, Carbon, and Bacteria Removal and Infiltration in Soil Columns

      Lance, J. C.; Whisler, F. D.; U. S. Water Conservation Laboratory, Phoenix, Arizona 85040; Department of Agronomy, Mississippi State University, State College, Mississippi 39762 (Arizona-Nevada Academy of Science, 1975-04-12)
      Denitrification is the only reaction capable of removing the tremendous quantity of nitrogen applied when high-rate land filtration systems are used for renovating sewage water. This study determined that a shortage of organic carbon limits denitrification, and the effects of increased dissolved organic carbon concentrations on soil clogging and movement of fecal coliform bacteria are clearly shown. Finally, the removal of dissolved organic carbon at different carbon concentrations during high rate soil filtration (40-50 cm/day) also limits denitrification.
    • Freeze-Thaw Effects on Soils Treated for Water Repellency

      Fink, Dwayne H.; Mitchell, Stanley T.; U. S. Water Conservation Laboratory, Phoenix, Arizona 85040 (Arizona-Nevada Academy of Science, 1975-04-12)
      Water can be supplied to many arid areas by harvesting the precipitation that falls on artificially prepared water-repellent soil catchments. The failure, in 1973, of wax-treated water harvesting catchment led to this study which indicates that the failure was due to swelling and shrinking of the treated soil which caused complete structural breakdown and loss of repellency. The laboratory freeze-thaw studies demonstrated that the smoother the plot, the less chance of freeze-thaw damage. Generally, coarser-textured soil can withstand freeze-thaw cycles better than finer-textured soils. Soil properties, other than texture, may also affect resistance to damage by freeze-thaw cycles. Increasing the repellent application rate may improve resistance to breakdown.
    • The Geomorphic and Hydraulic Response of Rivers

      Simons, D. B.; College of Engineering, Colorado State University, Fort Collins, Colorado 80523 (Arizona-Nevada Academy of Science, 1975-04-12)
      The importance of water resources and an increasing interest on improvement of out environment have identified the urgent need for methods to predict river response due to various changes resulting from proposed water resource planning. Fluvial geomorphology and hydraulic elements that are related to the interpretation and modeling of response to the problem are presented. Interpretation of alluvial rivers should be preceded by a qualitative analysis and information is presented which should be adequate to carry this out in most cases. This should be followed by a quantitative evaluation of channel response and water sediment routing using theory supplemented by physical and mathematical model studies of the system.
    • Measuring Snow Cover from ERTS Imagery on the Black River Basin

      Aul, Jerry S.; Ffolliott, Peter F.; School of Renewable Natural Resources, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1975-04-12)
      The possibility of using imagery from the earth resources technology satellites (ERTS) to monitor changes in areal snow cover in east-central Arizona is examined. Four methods were used in the interpretation of areal snow cover from the ERTS imagery, the densitometer, dot grid, squares grid and projection-planimeter methods providing results of 69, 71, 72 and 74 percent of areal cover respectively. No one method for interpretation of ERTS imagery should be ruled unusable, but any use made of ERTS imagery is dependent upon turn-around time for obtaining the imagery, as snow cover information which cannot be obtained within 24 hours is limited in practical application.
    • Parameter Influence on Runoff Modeling

      Kao, Samual E.; Roefs, Theodore G.; Ince, Simon; Ferguson, Morris & Associates, Inc., Scottsdale; Department of Hydrology & Water Resources, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1975-04-12)
      The influence of some model parameters on runoff simulation was investigated. The model parameters considered included space and time increments, rainfall input, and channel roughness. The parameters' effect on runoff appeared to be very small, but channel roughness greatly influenced flow depth.