• Applicability of the Universal Soil Loss Equation to Semiarid Rangeland Conditions in the Southwest

      Renard, K. G.; Simanton, J. R.; Osborn, H. B.; United States Department of Agriculture, Agricultural Research Service, Western Region, Southwest Watershed Research Center, Tucson, Arizona 85705 (Arizona-Nevada Academy of Science, 1974-04-20)
      An erosion prediction method that has recently received wide attention in the United States is the universal soil loss equation which is given as: a=rklscp. Where a = estimated soil loss (tons/acre/year), r = a rainfall factor, k = a soil erodibility factor, l = a slope length factor, s = a slope gradient factor, c = a cropping-management factor, and p = an erosion control practice factor. Data collected on the walnut gulch experimental watershed in southeastern Arizona were used to estimate these factors for semiarid rangeland conditions. The equation was then tested with data from watersheds of 108 and 372 acres. The predicted value of annual sediment yield was 1.29 tons/acre/year as compared with an average 1.64 tons/acre/year for 4 years of data for the 108-acre watershed, and a sediment yield of 0.39 tons/acre/year was predicted for the 372-acre watershed as compared with the measured value of 0.52 tons/acre/year. Although good agreement was noted between predicted and actual sediment yield, additional work is needed before the equation can be applied to other areas of the southwest.
    • Application of Remote Sensing in Floodway Delineation

      Clark, Robin B. (Arizona-Nevada Academy of Science, 1974-04-20)
      Population pressures on the land resources of Arizona have led to the sale and development of areas subject to flooding and because of the inadequacy of land use controls, the area is open to various land speculation schemes and unplanned subdivision growth. A floodplain delineation project was conducted for the planning department of Cochise County, Arizona, in which imagery acquired by earth resources technology satellite (ERT-1) and by high-altitude aircraft was employed. Parameters of the analysis included soils and geomorphology, vegetation, hydrologic calculations, and historical data. Floodplain soils lack developed b horizons, as compared to older, more mature soils not subject to flooding. General soil maps can only be used as guidelines, but a detailed soil survey can add significantly to the accuracy of image interpretations. Erosion-affected soil tones in areas adjacent to active channels proved beneficial in that the heightened contrast served to enhance resolution of vegetation-type boundaries. Hydrologic calculations were done based on valley cross-sections surveyed at two-to-three mile intervals. The historic data input into the system of floodplain delineation is dependent on the location of high-water marks and on obtaining a record of the amount of rainfall which resulted in the high-water mark.
    • A Bacterial Water Quality Investigation of Canyon Lake

      Horak, W. F.; Lehman, G. S.; Department of Watershed Management, The University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
      Fecal coliform counts in relation to number of swimmers along with fecal streptococci counts of water samples from Canyon Lake in central Arizona are reported. The presence of swimmers was related to an increase in fecal coliforms which was attributed to organisms shed from the swimmers and from agitation of the bottom sediments, consequently dispersing much of the bacteria contained in the benthos. From sampling of the swimming areas it was determined that livestock waste was the primary source of pollution (a greater number of fecal streptococci was found than fecal coliforms), but this interpretation could be misleading due to the higher survival rate of fecal strep than that of fecal coliform organisms.
    • A Bibliographic Information System for Water Yield Improvement Practices

      White, Linda M.; Department of Watershed Management, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
      Effects of vegetation management on water and other renewable natural resources and amenities are subjects of a computerized reference retrieval information system operated out of the department of watershed management, university of Arizona. Although WaMIS (watershed management information system is a subsystem of the arid lands information system, it has its own unique scope. The system, which serves as a link between bibliographic material and users who need access to the information, provides a personalized bibliography for the user in his area of interest. Documents identified as relevant to the system's scope are abstracted and indexed, and references stored in a computer bank. In response to specific inquiries from users, the computer tapes are searched under indexing terms, author, and/or data, and a printout of citations (giving author, data, title, source, abstract, and indexing terms) relevant to the inquiry is sent to the user.
    • Display and Manipulation of Inventory Data

      Gale, R. D.; Russel, J. W.; Siverts, L. E.; Tonto National Forest, Phoenix, Arizona; Southwestern Region, U.S.F.S., Albuquerque, New Mexico (Arizona-Nevada Academy of Science, 1974-04-20)
      A stochastic model is presented for the prediction of sediment yield in a semi-arid watershed based on rainfall data and watershed characteristics. Random variables which lead to uncertainty in the model are 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, and 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. Applications of the model are 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 of the watershed. In order to calibrate the model and to evaluate the uncertainties involved, experimental data from the Atterbury watershed near Tucson, Arizona were used.
    • The Effect of Development on Groundwater in the Parker Strip

      Everett, L. G.; Schultz, T. R.; Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1974-04-20)
      The 14.6 miles of the Colorado River bounded by Parker Dam and Headgate Rock Dam has been referred to as the Parker Strip. This river reach has become a high use recreation area during the past decade with 4,000 permanent residents and as many as 120,000 water enthusiasts on long weekends. The riparian area of the river is heavily clustered with mobile homes, marinas and public beaches. The means of sewage disposal is exclusively via septic tanks. Recent surveys by the Environmental Protection Agency, Arizona State Department of Public Health and the University of Arizona have localized surface water bacteria levels that may indicate a developing groundwater problem. The geohydrology of the area indicates that the septic tanks are located in Post -Pliocene Colorado River deposits. The deposits are quite thin and relatively narrow. Since the deposits are locally derived sands and gravels, the horizontal hydraulic conductivities are such that a relatively short flow time to the river may result. Intensive evaluation of the degradation of the water quality in these deposits is needed to determine if the ground water supply was jeopardized by septic tank systems.
    • Establishing a Process Framework for Land Use Planning (invited)

      Lundeen, Lloyd J.; Watershed Systems Development and Application Unit, U. S. Forest Service, Berkeley, California (Arizona-Nevada Academy of Science, 1974-04-20)
      The operational aspects of land use planning, to be effective, must be tied to a well defined planning process. The framework for this process includes a set of main components which are important in solving land use planning problems. These components are linked together in a design related to the basic concepts of decision analysis which has been oriented to natural resource problems. Detailed description can be added to the .process framework to tailor it to a specific problem, study area, or study level. Some of the major components in the framework are an objectives and goals spectrum, problem formulation, physical characterization of the land, social and economic demands analysis, identification of management alternatives and specific activities, simulation of resource response, allocation of resources, visual quality analysis, transportation system analysis, and a data management system. This process framework is d »sinned to he dynamic, user oriented, and compatible with the type of problems encountered in land use planning.
    • Fresh Water for Arizona by Salt Replacement Desalination

      Muller, Anthony B.; Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona 85721 (Arizona-Nevada Academy of Science, 1974-04-20)
      The process of salt replacement desalination proposed is believed to be able to produce vast quantities of fresh water be desalination. This method, which is a novel approach to minimizing the costs of saline water conversion, consists of the substitution of solutes in a solution to be desalted by a replacer chemical, and the low energy removal of that replacer chemical. The ultrafiltration of larger molecular sized replacer chemicals with high flux membranes increases the produce yield rate and reduces the corresponding energy requirement, with respect to reverse osmosis. In addition, the initial captial investment is less since no pressure constraining devices are required. The alteration of the osmotic pressure of the replacer solution within the process can also take advantage of energy savings through the utilization of an easily reversible reaction which synthesizes and breaks down a constituent that has a significant osmotic pressure difference between phases. Finally, the unusual process of fixed gel syneresis shows potential as a low energy salt replacement type process, but still requires extensive investigation.
    • Hydrologic Aspects of Land-Use Planning at Tumamoc Hill, Tucson, Arizona

      Popkin, Barney Paul; Soils, Water and Engineering Department, The University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
      Tumamoc Hill, an 869-acre (352 ha) desert area near Tucson, Arizona, is being considered as a controlled- access environmental site. Water affects the site's geology, soils, vegetation, wildlife, and archaeology. The Hill is drained by three small watersheds. The largest is rapidly urbanizing upstream. Hydrologic aspects include potential flooding and erosion hazards. These may be reduced simply, economically, and wisely in a land-use plan. Upstream development increases storm runoff volumes, and flood peaks, and frequencies routed through the site, and threatens existing downstream urban development. Return periods of channel-overflow floods become shorter with urbanization. The region may be managed to reduce hydrologic hazards by three procedures: widen channels, install low checkdams, and vegetate drainageways. These methods will slow down runoff velocities, and increase cross -sectional area of flow and roughness coefficient. More water would also be available for vegetation and wildlife. The land-use plan should include environmental education programs. These would present important effects of water on the natural ecology, and hydrologic aspects of watershed urbanization.
    • Increasing Forage Production on a Semiarid Rangeland Watershed

      Tromble, J. M.; United States Department of Agriculture, Agricultural Research Service, Western Region, Southwest Watershed Research Center, Tucson, Arizona 85705 (Arizona-Nevada Academy of Science, 1974-04-20)
      Two native grass species, blue grama and sidecoats, were successfully seeded on a semiarid rangeland on the walnut gulch experimental watershed in southeastern Arizona. Optimum seeding dates selected were those within the time period most likely to receive precipitation, and grass stands were established in two successive years with average rainfall. Shrubs were killed by root-plowing at a depth of 14 inches, a procedure which was more than 95% successful in controlling sprouting shrubs. Forage production measurements taken on nm-28 sideoats and Vaughn sideoats showed a yield of 1,950 and 2,643 pounds of forage per acre, respectively, for the 2 years following the seeding, whereas untreated sites produced 23 and 25 pounds per acre of forage. Results indicate that success in establishing a stand of native grass is increased through use of existing hydrologic data.
    • Metropolitan Operated District for Sewage Effluent - Irrigation Water Exchange

      Cluff, C. Brent; DeCook, K. James; Water Resources Research Center, The University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
      A plan for the reuse of sewage effluent is proposed for the city of Tucson, Arizona. Several kinds of use would be possible, but utilization for irrigation of existing farmland in the Avra-Marana area seems particularly attractive for several reasons: (1) conveyance can be accomplished by gravity flow, (2) no tertiary treatment is required for the presently grown crops, (3) the nutrients in the effluent would be better used, and (4) effluent use would reduce the pumpage of high quality groundwater, conserving it for municipal or other uses. An exchange of wastewater for groundwater for use in the city system is seen as a good alternative to the present practice of the city purchasing farmland in Avra valley in order to acquire the groundwater for conveyance to the Tucson basin. Objectives to maximize the quantity and efficiency of wastewater use may not appear compatible with the profit maximization motive of the individual farmer, and suitable provisions will have to be written into wastewater sales agreements to assure coordination between user and supplier.
    • Preliminary Investigations of the Hydrologic Properties of Diatremes in the Hopi Buttes, Arizona

      Scott, Kenneth C.; Edmonds, R. J.; Montgomery, E. L.; Northern Arizona University; U. S. Geological Survey, Flagstaff (Arizona-Nevada Academy of Science, 1974-04-20)
      Diatremes of Late Pliocene age in the Hopi Buttes area of Arizona are becoming increasingly important sources of groundwater to the Indian nations. These volcanic vent structures are prime sources of groundwater because sedimentary formations in the Hopi Buttes area yield only limited amounts of water or yield poor quality water. Diatremes act as traps for groundwater and some have yielded moderate amounts of good quality water to wells. Surface geologic investigations and analysis of drillers' logs indicate that structural relationships and diatreme lithology provide a means to project the hydrologic properties of the vent. Diatremes most suitable for groundwater development should have a diameter greater than one half mile, should contain volcanic tuff and breccia at its center, and should be fractured from collapse. Lava flows covering diatremes reduce recharge from sheet wash or from ephemeral stream flow. Data from geomagnetic and gravity surveys will be analyzed to determine its suitability for predicting subsurface size, shape, and lithology of the diatreme. The integration of geophysical and surface geologic data will reveal the total geometry of the structure enabling the most accurate appraisal of the hydrologic properties of the diatreme.
    • A Rational Water Policy for Desert Cities

      Matlock, W. G.; Agricultural Engineering, Soils, Water and Engineering Department, University of Arizona (Arizona-Nevada Academy of Science, 1974-04-20)
      Four sources of water supply for desert cities are rainfall, runoff, groundwater, and imported water, and the potential use for each varies. The government can institute various policy changes to eliminate or reduce the imbalance between water supply and demand. Restrictions should be placed on water-use luxuries such as swimming pools, subdivision lakes, fountains, etc. Water pricing should be progressive; each unit of increased use above a reasonable minimum should be charged for at an increasing rate. Runoff from individual properties, homes, storage, and supermarkets should be minimized through the use of onsite recharge wells, and various collection methods should be initiated. A campaign to acquaint the general public with a new water policy must be inaugurated.
    • Structural Relations Determined from Interpretation of Geophysical Surveys: Woody Mountain Well Field, Coconino County, Arizona

      Scott, Phyllis K.; Montgomery, E. L.; Northern Arizona University (Arizona-Nevada Academy of Science, 1974-04-20)
      The Coconino Sandstone of Permian age is the principal aquifer for the Woody Mountain well field, a source of municipal water for the City of Flagstaff. Wells of highest yield are located where the frequency of occurrence of faults is greatest and where the principal aquifer is down-faulted. The locations and displacements of all but the most prominent faults cannot be determined using conventional geologic mapping techniques because relatively undeformed Late Cenozoic basaltic lavas cover the faulted Paleozoic rock terrain. Approximately 3,500 feet of Paleozoic sedimentary rocks, which have little magnetic effect and which have a density of approximately 2.4, comprise most of the stratigraphic section in the well field. The basalt cover is strongly reversely magnetized and has a density of approximately 2.7. Changes in thickness of the basalt cover cause changes in the geomagnetic and gravitational field strength. Analysis of data from geomagnetic and gravity surveys was used to delineate boundaries and thicknesses of blocks of basalt which fill down -faulted areas. The correlation coefficient (r² = 0.96) for plots of known thicknesses of basalt versus complete Bouguer anomaly supports use of gravity data to estimate displacement of down -faulted blocks.
    • A Technique to Evaluate Snowpack Profiles in and Adjacent to Forest Openings

      Ffolliott, Peter F.; Thorud, David B.; Department of Watershed Management, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1974-04-20)
      Profiles of snowpack build-up in openings in forest overstories have been widely observed; however, a quantitative characterization of such a snowpack profile would aid in developing empirical guidelines for improving water yields from snowpacks. A technique is outlined that illustrates (a) evaluating snowpack profiles in and adjacent to individual forest openings in terms of increase or decrease in water equivalent, and (b) defining trade-offs between the estimated increase or decrease in snowpack water equivalent and the forest resource removed. Snowpack water equivalent during peak seasonal accumulation was measured in and adjacent to a clearcut strip in a ponderosa pine stand in north-central Arizona. A 4-degree polynomial, which defines the snowpack profile in terms of deposition, redistribution, and ablation characteristics, was empirically selected to describe snowpack water equivalent data points. An increase of 60 percent in snowpack water equivalent was realized by removing 46 percent of the ponderosa pine in the zone of influence, using a strip equal to one and one-half the height of the adjacent overstory.
    • Time-Related Changes in Water Quality of Stock Tanks of Southeastern Arizona

      Wallace, D. E.; Schreiber, H. A.; Southwest Watershed Research Center, Tucson, Arizona 85705 (Arizona-Nevada Academy of Science, 1974-04-20)
      This study attempts to determine the water quality changes in stock tanks and what factors are instrumental in the changes, and to assess the effects of the changes. Algal growth was the most prominent change taking place in the tanks with time. Little change in the water chemistry was noted until just before the tanks dried up. As algae died, ions tied up by the algae were released to the water, causing an increase in concentration of many of the nutrients. In order to determine the impact of various factors on algal growth, the data from eight stock tanks were analyzed by stepwise linear regression. Although 20 variables were used in the complete analysis, six variables were associated with 56.3 percent of the variance: time (since first sampling), total n, potassium, pH, inflow (recharge to the tanks), and hco3 concentration. Time and total n explained 51.3 percent of the variance, and potassium increased the variance to 52.8 percent. The pH reversed the relative positions of time and total n, with total n becoming dominant. The last two factors, inflow and hco3 were negative (resulting in a decrease in algal population) and increased the coefficient of variance to 56.3 percent.
    • 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.