• The Role of the States in Control of Weather Modification

      Davis, Ray Jay; College of Law, the University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1976-05-01)
      It now appears that, at least for the near future, the only federal controls of weather modification will be the record keeping and reporting requirements of the National Oceanic and Atmospheric Administration. About two-thirds of the states have enacted cloud seeding laws to fill the regulatory void. These statutes, however, are quite varied and many of them are inadequate. Accordingly, there is a need for "suggested" or "model" state weather control legislation. In a project funded by the Office of Water Research and Technology and administered through the Arizona Water Resources Research Center, such a proposed law has been prepared. It delegates means of control over seeding to an administrative agency, authorizes governmental funding of operations, establishes procedures and criteria for professional licensing of cloud seeders, creates a system for regulation of projects through operational permits, requires record keeping and reporting, and sets standards for resolution of water rights and legal liability issues.
    • A Multiobjective Approach to Managing a Southern Arizona Watershed

      Golcoechea, Ambrose; Duckstein, Lucien; Fogel, Martin M.; Department of System and Industrial Engineering, University of Arizona, Tucson, AZ 85721; Department of Hydrology and Water Resources, University of Arizona, Tucson 85721 (Arizona-Nevada Academy of Science, 1976-05-01)
      The case study of an Upper San Pedro River watershed is developed to show how a multiple objective approach to decision-making may be used in watershed management. The effects of various land treatments and management practices on water runoff, sediment, recreation,, wildlife levels, and commercial potential of a study area are investigated while observing constraints' on available land and capital. The example involves the optimization of five objective functions subject to eighteen constraints. In an iterative manner, the decision-maker proceeds from one noninferior solution to another, comparing sets of land management activities for reaching specified goals, and evaluating trade-offs between individual objective functions. This technique, which involves the formulation of a surrogate objective function and the use of the cutting plane method to solve the general nonlinear problem, hopefully provides a compromise between oversimplified and computationally intractable approaches to multiobjective watershed management.
    • Evaluation of Recharge Through Soils in a Mountain Region: A Case Study on the Empire and the Sonoita Basins

      Kafri, U.; Ben-Asher, J.; Water Resources Research Center, University of Arizona, Tucson 85721 (Arizona-Nevada Academy of Science, 1976-05-01)
      A conventional water balance method, employing long-term average values of rainfall, runoff and evapotranspiration yields near-zero recharge values for the Empire and the Sonoita basins. These results, however, are not in agreement with those obtained from an analysis of the local ground water regimes. A different approach for calculating recharge, based on the typical characteristics of these arid basins, is proposed. In particular, both basins are characterized by intense thunderstorms of short duration in the summer which occur usually towards the evening, and shallow, sandy-gravelly soils with a relatively high permeability overlying fractured rocks in the elevated mountain regions. These factors may cause a considerable amount of water to infiltrate through the soil profile, thereby escaping evapotranspiration during the following day. The proposed model deals with separate thunderstorm events using mean values of rainfall intensity and frequency corresponding to elevation. This model was coupled with a numerical solution of the flow equation which was used to solve the one dimensional water flow through a soil profile. The solution includes sink terms and was solved for the simultaneous processes of infiltration, moisture redistribution and evapotranspiration. The results obtained show almost no recharge in the low valleys, but significant recharge in the mountains. The amount of recharge increases with elevation and decreases with the depth of the soil profile.
    • Geomorphic Thresholds and Their Influence on Surface Runoff from Small Semiarid Watersheds

      Wallace, D. E.; Lane, L. J.; Southwest Watershed Research Center, Tucson, Arizona 85705 (Arizona-Nevada Academy of Science, 1976-05-01)
      The geomorphic threshold concept of landform evolution and its effect on hydrologic performance of drainage systems was investigated on small semiarid watersheds in Southeastern Arizona. Thresholds develop within a geomorphic system with time and can, when exceeded, cause drastic changes in the geomorphic features and in the hydrologic performance of the watershed. The slow continuous evolution of drainage characteristics can be suddenly altered with major readjustment of the landscape taking place. A new state of dynamic equilibrium will then prevail until the drainage system is again subjected to conditions which cause some geomorphic threshold to be exceeded. Areas of potential geomorphic readjustment can be identified from parameters such as channel slope, average land surface slope, drainage density, and mean length of first order streams and these data can be used as components in a calibrated kinematic-cascade model to determine the effects of various degrees of drainage system alteration. The influence on runoff from exceeding various geomorphic thresholds is tested and the resulting hydrologic modifications are simulated and discussed.
    • Equilibrium Condition and Sediment Transport in an Ephemeral Mountain Stream

      Heede, Burchard H.; Rocky Mountain Forest and Range Experiment Station, Tempe, Arizona (Arizona-Nevada Academy of Science, 1976-05-01)
      Flow frequency curves supported the hypothesis that channel-forming flows are exceptional events in ephemeral mountain streams. This was substantiated by the lack of a relationship between sediment production and sediment yield. Numerous bed nickpoints indicated channel instability, despite gravel bars and log steps that are part of the slope adjustment processes. Due to differences in structural density between bars and steps, size distribution of the sediment deposits above them differs. Although only qualitative guidelines are presented, the watershed or wildlife manager should be in a position to utilize the formation of gravel bars and log steps for his management goals.
    • Water Quality of Streamflow from Forested Watersheds on Sedimentary Soils

      Gregory, Paul W.; Ffolliott, Peter F.; School of Renewable Natural Resources, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1976-05-01)
      To provide quantitative baseline information on water quality of streamflow from ponderosa pine watersheds on sedimentary soils, water samples were collected at the mouths of four watersheds at time of surface runoff and during extreme or unusual hydrological events. In each sample, calcium (Ca++), magnesium (Mg++) and sodium (Na+) were determined by using atomic absorption spectrophotometry; carbonate (CO=3) and bicarbonate (HCO-3) were measured by titrating with standard acid; fluoride (F-), sulfate (SO=4), 3 nitrate (NO-3), and chloride (Cl-) were determined by colorimetric methods using an Autoanalyzer; hydrogen ion concentration (pH) was measured by using a glass electrode; and suspended sediment concentrations were determined by filtration. The data obtained were compared with EPA water quality standards for aquatic life, irrigation, and public water supply. Although the EPA levels of acceptability have not been established for many of the chemical and physical water constituents, the parameters determined in this study, in general, fall within the EPA prescribed limits.
    • Preliminary Results from a Study of Coal Mining Effects on Water Quality of the Tongue River, Wyoming

      Olsen, Richard D.; Dettmann, Edward H.; U. S. Energy Research and Development Administration; Division of Environmental Impact Studies, Argonne National Laboratory, Argonne, Illinois 60439 (Arizona-Nevada Academy of Science, 1976-05-01)
      A preliminary assessment survey, preparatory to a comprehensive ERDA sponsored watershed study, was conducted in the vicinity of Sheridan, Wyoming on the Tongue River and its major tributaries during the summer of 1975 to determine the extent and magnitude of aquatic environmental impacts induced by strip mining of coal at one major mine in the western Powder River Basin of Wyoming. Results of detailed physical and chemical analysis of mine discharge and ambient water quality of receiving streams were not conclusive, but suggest that water quality impacts of present mining activities in the area examinee' are small when compared to other apparent land use impacts observed upstream of the mine.
    • Future Effects of the CAP on Lake Havasu's Thermal Regime

      Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona 85721 (Arizona-Nevada Academy of Science, 1976-05-01)
      A temperature-stratification model developed by the U. S. Army Corps of Engineers, Hydrologic Engineering Center, was used to predict the changes in the temperature profile of Lake Havasu on the Colorado River near Parker, Arizona, that may occur with the withdrawal of Central Arizona Project (CAP) water in the 1980's. This quantified change in temperature-dependent density stratification was calculated using maximum withdrawal conditions to accentuate and expose any major changes which could be potential problems. Inputs for this program include monthly evaporation and precipitation, monthly average air temperature, solar radiation at the top of the atmosphere, water inflow amount and temperature, water outflow amount and location, water temperature profiles, and physical reservoir data. In the calibration of the model, the five coefficients were found to differ slightly from regional coefficients established by the Hydrologic Engineering Center, Davis, California, and coefficients established in a previous study. End of month temperature profiles were then generated for average meteorological conditions, both with and without maximum CAP flow. The computed results indicate that the stratification changes will be of low magnitude.
    • Chlorofluorocarbons as Hydrologic Tracers, A New Technology

      Randall, J. H.; Schultz, T. R.; Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona 85721 (Arizona-Nevada Academy of Science, 1976-05-01)
      The nationwide research undertaken to study environmentally dispersed chlorofluorocarbons introduced into the atmosphere from aerosol cans and refrigeration systems has indicated that these compounds are potentially ideal hydrologic tracers, especially Freon-11 (Cl₃CF). The major advantages of Cl₃CF as a tracer are its non-polluting conservative nature, extremely low toxicity and sorptivity on clays, quantifiable build-up in the atmosphere, and a detection limit of about 10⁻¹⁴ grams. Quick and inexpensive detection of Cl₃CF can be done using a field-operable gas chromatograph with a pulsed electron-capture detector system. The presence of Cl₃CF in ground water, indicating an age of less than 30 years, will permit delineation of recent recharge areas. The absolute age of the recharging water is proportional to the atmospheric concentration of Cl₃CF at the time of recharge. The simple quantifiable increase of Cl₃CF in the atmosphere should therefore yield more accurate ages than those determined by tritium analysis.
    • Water Quality Study of Lake Havasu, Arizona Near the CAP Intake Area

      Ince, Simon; Kreamer, David L.; Young, Don W.; Constant, Charles L.; Department of Hydrology and Water Resources, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1976-05-01)
      Throughout 1974 and 1975 the Department of Hydrology and Water Resources, University of Arizona, conducted a water quality study on Lake Havasu, Arizona, near the Central Arizona Project intake. This investigation was funded jointly by the Arizona Water Commission and the U.S. Bureau of Reclamation. The University study evaluated the hydrography and hydrology, sediments, turbidity, temperature, chemistry, dissolved oxygen (and biochemical oxygen demand), benthic invertebrates, phytoplankton, zooplankton, biomass analysis, and electrical conductivity to establish baseline data for the CAP intake area. The results showed weak stratification and generally good aeration in the lake and high turbidity in the Bill Williams River. Biological quality was good with low amounts of benthics and numerous zooplankton and phytoplankton species. The extensive data from chemical analysis generally conformed to public health standards.
    • Resolutions of Analog Rainfall Records Relative to Chart Scales

      Chery, Donald L, Jr.; Beaver, Dave G.; USDA, Agriculture Research Service, Western Region, Southwest Watershed Research Center, Tucson, Arizona 85705; Soils, Water and Engineering Department, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1976-05-01)
      Five rainfall distributions, four l-in rainfall depths and one 3-in rainfall depth were plotted on charts with five different combinations of time and depth scales. The plotted events were read on an analog-to-digital converter by four different researchers. Each reading of a plotted record was compared with the known simulated rainfall-rate distribution. The correspondence of the rainfall rates read from the charts with the actual rainfall rate distribution is measured by an integral squared error and correlation coefficient. The results showed a general correspondence between error and the chart scale and a strong influence of maximum recorded rate and rate distribution on the error. For the chart scales evaluated, error did not become more directly associated with scale, except when recorded rates were less than about 10 in/hr. Error was directly related to the number of points read in any given trace by the relation E = 16.3N^(-0•426).
    • Application of a Double Triangle Unit Hydrograph to a Small Semiarid Watershed

      Diskin, M. H.; Lane, L. J.; Department of Hydrology and Water Resources, University of Arizona, Tucson; United States Department of Agriculture, Agricultural Research Service, Western Region, Southwest Watershed Research Center, Tucson, Arizona (Arizona-Nevada Academy of Science, 1976-05-01)
      Hydrographs of runoff from small watersheds in semiarid regions often have a sharp peak with a relatively short time of rise followed by a slower recession and a tail of low flow. This characteristic shape suggests the possible use of a double triangle unit hydrograph recently introduced to hydrology. The shape of this unit hydrograph is specified by four parameters, which may be estimated by an optimization procedure based on using the sum of absolute deviations or some other suitable criterion as an objective function. Rainfall and runoff data for a number of storm events on a small watershed in the Santa Rita Experimental Range in southeastern Arizona have been analyzed to test the above idea. Double triangle unit hydrographs were fitted to individual storm events. The differences in the shapes of individual unit hydrographs were found to be small so that they could be approximated by a single double triangle unit hydrograph.
    • Determining Areal Precipitation in the Basin and Range Province of Southern Arizona - Sonoita Creek Basin

      Ben-Asher, J.; Randall, J.; Resnick, S.; Water Resources Research Center, University of Arizona, Tucson, Arizona 85721 (Arizona-Nevada Academy of Science, 1976-05-01)
      A linear relationship between point precipitation and elevation in conjunction with a computer four-point interpolation technique was used to simulate areal rainfall over Sonoita Creek Basin, Arizona. The simulation's sensitivity and accuracy were checked against the official isohyetal map of Arizona (Univ. of Arizona, 1965) by changing the density of the interpolation nodes. The simulation was found to be in good agreement with the official map. The average areal-rainfall was calculated by integration. Cumulative rainfall amounts were assumed to be stochastically independent from one season to another. The seasonal precipitations of forty years (1932-1972) were subdivided into five groups. to check for binomial distribution. The binomial model fits the historical data adequately. The binomial model for cumulative seasonal areal-precipitation provides one way to compute the return period. This information will be necessary for decision-makers and hydrologists to predict the area's future water balance.
    • Evaluating Water Quality Sampling Schedules Using Fecal Coliform Concentrations in Sabino Creek

      Motschall, Robert M.; Brickler, Stanley K.; Phillips, Robert A.; School of Renewable Natural Resources, University of Arizona, Tucson, Arizona; Civil Engineering, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1976-05-01)
      Sabino Canyon Recreation Area, adjacent to Tucson, and a major water-based recreation complex within the Santa Catalina Mountains, Coronado National Forest, receives intensive recreational use. This natural water resource area with primary water contact activities was monitored for fecal coliform in accordance with U.S. Forest Service Regulation (FSM 2542.2). As part of a larger study, this report discusses the relationships between time, day, and location of sampling with fecal coliform bacterial concentrations in Sabino Creek. Analysis of Variance shows that fecal coliform concentrations were higher: 1) on Sunday than Wednesday, 2) at 4:00PM than 8:00AM or 12:00 Noon, and 3) in the lower section of the four miles of the study area. This research provides the U.S. Forest Service with baseline water quality data and a benchmark from which to continue an efficient water quality monitoring program.
    • NAIWMC - Potential in the Southwest

      Keyes, Conrad G., Jr.; North American Interstate Weather Modification Council, Las Cruces, New Mexico 88003 (Arizona-Nevada Academy of Science, 1976-05-01)
      The North American Interstate Weather Modification Council was formed to coordinate intrastate, interstate and possible international weather modification activities. The main purpose of this organization is to achieve and maintain state and local control of such activities while endeavoring to attain a high degree of legislative uniformity and an effective information exchange mechanism. The need, goals and objectives of the newly created Council are summarized. A summary of the Council's progress at performing the purposes of the Council are presented in this paper. The potential use of this Council in the Southwest is described in relation to existing programs in weather modification in the area.
    • Past Mining Activities and Water Quality in the Lynx Creek Watershed

      Felix, E. N.; Verma, T. R.; McCrary, E. E.; Thames, J. L.; Prescott National Forest, U.S.D.A., Forest Service; School of Renewable Resources, University of Arizona (Arizona-Nevada Academy of Science, 1976-05-01)
      Lynx Lake Watershed consists of approximately 13,600 acres of the Agua Fria drainage. About 13 percent of the area is patented mining claims (mainly copper} with numerous mining shafts, waste dumps, and mill tailings. Lynx Creek itself was once mined for gold and the creek bed still shows the scars of the dredging operations. Drainage from the numerous old mining sites show a certain extent of toxic mineral and sediment pollution of the water resources in the area. Lynx Creek carries runoff which is slightly acidic in nature and has a high concentration of copper, manganese, iron, zinc, and sulfates. The Sheldon Mine complex is considered one of the major sources of pollution to the lake. Aquatic life and recreation potential of the watershed is greatly reduced by the water pollution problem. The pollutants from the abandoned mine sites enter into Lynx Lake, a trout fisheries lake, which was created by damming the creek in 1962 by the Arizona Game and Fish Department. The Sheldon Tailings pond was rehabilitated during the summer of 1975 as part of a reclamation study and demonstration project that is currently in progress and being sponsored by SEAM (Surface Environment and Mining}. The study is being conducted cooperatively by the School of Renewable Resources, University of Arizona, and the Prescott National Forest. An excellent vegetative cover is established on the site and studies are being conducted to measure the beneficial effects of the reclamation on water quality.
    • Application of Carbon-14 Ground-Water Ages in Calibrating a Flow Model of the Tucson Basin Aquifer, Arizona

      Campana, Michael E.; Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona 85721 (Arizona-Nevada Academy of Science, 1976-05-01)
      In the absence of pure piston flow, the carbon-14 ages of ground-water can be related to groundwater residence times only in the context of a flow model. To do this, a three-dimensional digital computer model of a portion of the Tucson Basin Aquifer was constructed using the theory of finite-state mixing cell models. The model was calibrated against the spatial distribution of adjusted carbon-14 ground-water ages, and once a reasonable fit was obtained, the ground-water residence times were calculated. The model also provides a first approximation to three-dimensional flow in the aquifer as well as an estimate of the long-term average annual recharge to the aquifer.
    • Windbreaks May Increase Water Yield from the Grassland Islands in Arizona's Mixed Conifer Forests

      Thompson, J. R.; Knipe, O. D.; Johnson, Phil M.; United States Department of Agriculture, Forest Service, Rocky Mountain Forest; Range Experiment Station, Forest Hydrology Laboratory, Arizona State University, Tempe (Arizona-Nevada Academy of Science, 1976-05-01)
      The general hydrologic characteristics, selected climatic factors, and soil properties of the high-elevation grasslands are compared to the surrounding forest. Evidence shows that water yield could be increased by 1-1/2 to 2 inches if snow could be held where it falls. It may be possible to establish tree windbreaks in the grassland by altering the microclimate during establishment, and introducing mycorrhiza with the planted seedlings. This conclusion is supported by good survival in a 2-year planting trial.
    • 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, Tucson (Arizona-Nevada Academy of Science, 1976-05-01)
      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.
    • On the Modeling and Computational Aspects of Dynamic Programming with Applications in Reservoir Control

      Sniedovich, Moshe; Yakowitz, Sidney J.; Department of Systems and Industrial Engineering, University of Arizona, Tucson, AZ 85721 (Arizona-Nevada Academy of Science, 1976-05-01)
      A discrete stochastic multistage decision model is developed, in the framework of which the dynamic programming algorithm is defined. It is demonstrated that the algorithm may be used as a solution procedure for non-routine reservoir control problems. The study demonstrates that analytical considerations may be used to significantly reduce the amount of computation needed for the implementation of the algorithm. Two reservoir control problems are studied: The "reliability problem" in which one seeks a minimum-cost operation rule under a constraint which specifies the maximum probability of shortage allowed during the life-time of the project, and the "range problem" in which the objective is the minimization of the expected value of the range of fluctuation around a critical storage level.