• An Analysis of Yearly Differences in Snowpack Inventory-Prediction Relationships

      Ffolliott, Peter F.; Thorud, David B.; Enz, Richard W.; Department of Watershed Management, University of Arizona, Tucson 85721; USDA Soil Conservation Service, Phoenix, Arizona 85025 (Arizona-Nevada Academy of Science, 1972-05-06)
      Inventory-prediction relationships between snowpack conditions and forest attributes may be useful in estimating water yields derived from snow, but such relationships are developed usually from source data collected over a short time period. Analyses of long-term data suggest inventory-prediction relationships developed from limited data may have more general application, however. Available records from 18 snow courses in the ponderosa pine type in Arizona provided source data in this study, which was designed to empirically analyze inventory-prediction relationships developed from long-term snow survey records. The primary hypothesis tested and evaluated by statistically analyzing the family of regression equations representing a snow course, was that, given a precipitation input, the distribution of snowpack water equivalent at peak seasonal accumulation is determined by the spatial arrangement of the forest cover, e.g. basal area. Generally 12 of the 18 snow courses evaluated appeared to support the hypothesis, three courses did not, and three courses were considered inconclusive.
    • Bed Material Characteristics and Transmissions Losses in an Ephemeral Stream

      Murphey, J. B.; Lane, L. J.; Diskin, M. H.; Southwest Watershed Research Center, Agricultural Research Service, USDA, Soil and Water Conservation Research Division; Arizona Agricultural Experiment Station, Tucson (Arizona-Nevada Academy of Science, 1972-05-06)
      An average of 6 to 13 streamflows from intense summer convective storms occurs annually in the walnut gulch experimental station, 58 square miles in southeastern Arizona. Flows last generally less than 6 hours, and the channels are dry 99 percent of the time. The limiting factors imposed by the geology and geomorphology of the channel to transmission losses of a 6 square mile channel in the station are described. The Precambrian to quaternary geology is outlined, and geomorphology of the channels are described. Volume, porosity and specific yield of alluvium were determined. There is 106 acre-feet of alluvium with a mean specific yield of 28 percent, and a maximum water absorbing capacity of 29 acre-feet or 7 acre-feet per mile of reach. Channel slope is insensitive to changes in geological material beneath it or to changes in flow regime. Channel cross section is highly sensitive to geology and flow regime. Transmission losses were highly correlated to volume of inflow.
    • Collective Utility of Exchanging Treated Sewage Effluent for Irrigation and Mining Water

      Ko, Stephen C.; Duckstein, Lucien; Systems & Industrial Engineering, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      The concept of collective utility is applied to a case study of alternative water resource utilization by providing a basis for comparing alternative uses of resources from the viewpoint of aggregate welfare. The exchange of sewage effluent for groundwater used by irrigation farmers, and the exchange of sewage effluent for groundwater used by processing and milling miners in Tucson, Arizona, are given as examples. Reviewed are collective utility concepts, case problems, definitions of problems, formulation of the model, and marginal change of collective utility. The first case has a collective utility of $800,500-g, where g represents unquantifiable factors, such as the reduction in quality of living due to the odor if solid waste exchanges. The second case has a collective utility of $175,000. Since it is likely that g will be on the order of $1 million per year, the first exchange is preferable to the second.
    • Converting Chaparral to Grass to Increase Streamflow

      Ingebo, Paul A.; Rocky Mountain Forest and Range Experiment Station (Arizona-Nevada Academy of Science, 1972-05-06)
      Chaparral covers 4 million acres in Arizona. There is interest in determining how much these lands contribute to surface water supply, and how this contribution could be changed by conversion of chaparral cover to grass or grass forb. Results from treatment in the Whitespar watersheds are interpreted. Live oak and true mountain mahogany dominate the study area, which averages 22.7 inches of annual precipitation. Whitespar B watershed was converted to grasses in 1967, and litter was not disturbed. The 246 acre watershed produced more streamflow than the untreated, 303-acre control which tended to remain intermittent. Prior to treatment, streamflow in both watersheds was quite well synchronized. Watershed b has since had continual flow. Winter flows contribute about 77 percent of the increased streamflow volume. The degree of effect is still under study, but a new rainfall-runoff relationship for the treated watershed is necessitated.
    • Design and Pilot Study of an Arizona Water Information System

      Foster, K. E.; Johnson, J. D.; Office of Arid Land Studies, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      Water information systems may have different demands, such as responding to queries about rainfall-runoff relationships, water level data, water quality data and water use. Data required for retrieval may need display, such as a hydrograph. Information systems are reviewed and results of specific water information agencies are reported. Agencies in Arizona are listed with their specific water information need. Development of a water activity file and water information system is outlined for Arizona as a pilot project. Linkage of units within the data system is shown, as is the information system's questionnaire to project leaders. Information currently in the system includes water quality from the state department of health for 450 wells in the Tucson basin, and water level, storage, storage coefficient and transmissivity supplied by the Arizona water commission for the Tucson basin and Avra Valley. Quality of data submitted to the system should be reflected in retrieval for better understanding of the data. This consideration is planned for the coming fiscal year.
    • Effect of a Grass and Soil Filter on Tucson Urban Runoff: A Preliminary Evaluation

      Popkin, Barney Paul; Water Resources Research Center, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      Storm runoff from the Tucson metropolitan area is unsuitable for most uses without processing. A lysimeter comprised of a grass and soil filter was constructed and is being evaluated as a water-quality treatment facility. The lysimeter is 200 feet long, 4 feet wide and 5 feet deep, and contains homogeneous calcareous loam covered by common grasses. Experimental apparatus was installed to divert less than a cubic foot per second of runoff from urbanized Arcadia Watershed. Runoff flows by gravity over the lysimeter, where surface inflow, surface outflow and subsurface outflow are measured and sampled. Four trials, each associated with a discrete runoff event, were conducted in the fall of 1971. Water samples were analyzed for inorganic chemical constituents, chemical oxygen demand (COD), coliforms, turbidity and sediment contents. Subsurface-outflow samples from initial trials were high in COD and total dissolved solids, representing soil flushing or leaching. Concentrations of inorganics reached a maximum value within a few hours of initial seepage, and then decreased. The peaking represents a salt build-up between trials. Concentrations of COD, coliforms, turbidity and sediment in subsurface-outflow samples decreased significantly during each trial. Surface-outflow samples had lower turbidity, COD, bacteria and sediment contents than surface-inflow samples. Turbidity, suspended and volatile solids, coliforms and COD in runoff samples may be reduced by grass and soil filtration. Increased grass development and soil settling work to produce a better quality effluent. Quantification of the lysimeter's effectiveness will be useful for urban watershed management.
    • Evaluation of a Turfgrass - Soil System to Utilize and Purify Municipal Waste Water

      Sidle, R. C.; Johnson, G. V.; Department of Soils, Water and Engineering, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      Sewage effluent for irrigation is well established. This study determines the capacity of selective turfgrass-soil systems to purify municipal sewage effluent and to measure the degree of utilization of nitrogen in the effluent by turfgrass. Chlorinated secondarily treated sewage effluent from the city of Tucson was applied to turfgrass grown on sandy loam, silt and loam, under three levels of irrigation under laboratory conditions of duplicate pots. Each pot had 2 suction probes to estimate soil moisture tensions and to allow soil water sampling. The study operated from September to March, 1972, for 30 weeks. Purification efficiency, nitrogen utilization and percent recharge were calculated. Turfgrass can be irrigated with sewage effluent at common rates without hazard of nitrogen pollution to groundwater. Purification efficiency exceeded 90 percent for all irrigation levels on sandy loam and silt. Nitrogen utilization was greater over sandy loam. Turfgrass-soil systems can utilize nitrogen and purify waste water.
    • An Evaluation of Current Practices in Seepage Control

      Boyer, D. G.; Cluff, C. B.; Water Resources Research Center, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      The need for increased control of seepage from both natural and artificial small ponds and lakes has become more apparent with the increased frequency of their construction and use on the farm, ranch, and in recreational urban use. Seepage control methods are also becoming more numerous. Unfortunately, comparisons as to effectiveness, longevity and costs are not readily available. This paper investigates some control techniques being used in this region and evaluated them according to the above criteria. Emphasis was on the use of available physiochemical methods other than rubber membranes and concrete liners. Examples of the types of controls in use include plastic, soil compaction aids, hydrophobic chemicals and monovalent cation applications, such as sodium chloride. Some examples of the use of these methods in Arizona are shown and the results of some field comparison tests conducted using 8 x 8 square foot double -ringed infiltrometers presented. Recommendations are made of additional research that should be undertaken to improve the technology of the control of seepage losses.
    • Groundwater Contamination in the Cortaro Area, Pima County, Arizona

      Schmidt, Kenneth D.; Harshbarger and Associates, Tucson, Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      High concentrations of nitrate have been found in water samples from irrigation wells north of the Tucson Arizona sewage treatment plant. The plant, which had primary treatment prior to 1951, produced 2,800 acre-feet of effluent in 1940, 4,600 acre-feet in 1950, 16,300 acre-feet in 1960, and 33,000 acre-feet in 1970. Large amounts of treated effluent recharge the groundwater system north of the plant. Sources of nitrate contamination beside sewage effluent may be sewage lagoons, sanitary landfills, meat packing and dairy effluent, septic tanks, and agricultural runoff. Sewage effluent is considered to be the primary source of nitrate contamination in the area. Geologic and flow net analysis indicate that aquifer conditions minimize the effects of sewage effluent contamination. Chloride and nitrate migration appears to be similar in the aquifer. Large-capacity wells were sampled to reflect regional conditions, and chemical hydrographs of chloride and nitrate were analyzed. The seasonal nature of these hydrographs patterns depend on total nitrogen in sewage effluent. Management alternatives are suggested to decrease nitrate pollution by sewage effluent.
    • The Groundwater Supply of Little Chino Valley

      Matlock, W. G.; Davis, P. R.; Soils, Water and Engineering Department, The University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      The little chino valley in central Arizona presents an interesting groundwater study as withdrawals exceed recharge. The groundwater surface is falling at about 2 feet per year over most of the area due to large irrigation development. A shallow water table aquifer overlies the artesian aquifer and receives recharge from irrigation runoff. Water quality in the artesian aquifer is excellent. Water quality in the water-table aquifer is poorer, being somewhat higher in total salts, but is suitable for most domestic and agricultural uses. Specific yield for the supply area to the artesian aquifer is 12 percent, with estimated annual recharge of 4000 acre feet and leakage from the aquifer of 2300 acre feet. Water budget and use for the basin is presented with water level and water quality data. The multiphase aquifer system is described and illustrated.
    • Man-Nature Attitudes of Arizona Water Resource Leaders

      Kanerva, Roger A.; King, David A.; Department of Water Resources, Annapolis, Maryland; Department of Watershed Management, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1972-05-06)
      A pilot study is developed to construct a scale which measures attitude towards human management in Arizona. The decision-maker's attitudes toward his man-made and natural environments are investigated in terms of cultural (interior), natural (intermediate), and balanced (exterior) reference positions. A decision-making model consists of stimuli (inputs), decision-making (process function), and response (outputs). The 12 questions developed and applied to Arizona water managers were reduced to 8 capable scalogram analysis. These scaled questions related to favoring physical or emotional needs of man, deciding who gets what or increasing the supply, including behavioral patterns, protecting environmental areas, manipulation of resources as harmful or beneficial, municipal and industrial demands, opinions of groups, and possible overuse of resources. The scale met 5 criteria, which are defined by reproducibility, non-scale pattern of response, number of questions, error ratio and cross checking of responses. This study may provide managers with means of objectively evaluating and improving decisions.
    • Nitrogen Species Transformations of Sewage Effluent Releases in a Desert Stream Channel

      Sebenik, P. G.; Cluff, C. B.; DeCook, K. J.; Water Resources Research Center, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      A preliminary study was made with the objective of examining nitrogen species transformations of treated sewage effluent releases within the channel of an ephemeral stream, the Santa Cruz River of southern Arizona. Water quality samples were taken at established locations in sequence so that peak daily flows could be traced as the effluent moved downstream. Results indicate that increased nitrification, coinciding with changing stream characteristics, starts in the vicinity of Cortaro Road (6.3 river miles from the Tucson Sewage Treatment Plant discharge). Through physical-chemical changes in streamflow, nitrate -nitrogen values reach a maximum at approximately 90-95 percent and 60-80 percent of total flow distance for low flows and high flows, respectively. Concentrations of ammonia-nitrogen and total nitrogen decrease continuously downstream with both high and low flows. Therefore, the rate of nitrification within sewage effluent releases in a desert stream channel evidently is related to flow distance and physical characteristics of the stream.
    • Objective and Subjective Analysis of Transition Probabilities of Monthly Flow on an Ephemeral Stream

      Dvoranchik, William; Duckstein, Lucien; Kisiel, Chester C.; Department of Systems and Industrial Engineering, University of Arizona; Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      A critique of statistical properties of monthly flows on an ephemeral stream in Arizona is given. A subjective procedure, justified for managerial purposes not concerned with the variability of flow within the month, is proposed for sequential generation of monthly flow data. Ephemeral flows should be modeled by starting with at least historical daily flows for more meaningful monthly flow models. Stochastic properties of monthly streamflows and state transition probabilities are reviewed with regard to ephemeral streams. A flow chart for a streamflow model geared to digital computers, with a simulation of streamflow subroutine, is developed. Meaningful monthly flow models could serve as a check on alternative models (subjective matrix, lag-one auto regressive, harmonic, bivariate normal, bivariate log-normal models). Rules and guidelines are presented in developing meaningful probability matrices.
    • A Proposed Model for Flood Routing in Abstracting Ephemeral Channels

      Lane, Leonard J.; Soil and Water Conservation Research Division, Agricultural Research Service, USDA; Arizona Agricultural Experiment Station, Tucson, Arizona; Southwest Watershed Research Center, Tucson, Arizona 85705 (Arizona-Nevada Academy of Science, 1972-05-06)
      Almost all runoff from semiarid rangeland watersheds in southern Arizona results from intense highly variable thunderstorm rainfall. Abstractions, or transmission losses, are important in diminishing streamflow, supporting riparian vegetation and providing natural groundwater recharge. A flood routing procedure is developed using data from the walnut gulch experimental watershed, where flood movement and transmission losses are represented by a system using storage in the channel reach as a state variable which determines loss rates. Abstractions are computed as a cascade of general components in linear form. Wide variation in the parameters of this linear model with increasing inflow indicates that a linear relation between losses and storage is probably incorrect for ephemeral channels.
    • Role of Modern Methods of Data Analysis for Interpretation of Hydrologic Data in Arizona

      Kisiel, Chester C.; Duckstein, Lucien; Fogel, Martin M.; Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona 85721; Department of Systems and Industrial Engineering | Department of Watershed Management (Arizona-Nevada Academy of Science, 1972-05-06)
      Mathematical models, requiring substantial data, of hydrologic and water resources systems are under intensive investigation. The processes of data analysis and model building are interrelated so that models may be used to forecast for scientific reasons or decision making. Examples are drawn from research on modeling aquifers, watersheds, streamflow and precipitation in Arizona. Classes of problems include model choice, parameter estimates, initial condition, input identification, forecasting, valuation, control, presence of multiple objectives, and uncertainty. Classes of data analysis include correlation methods, system identification, stationarity, independence or randomness, seasonality, event based approach, fitting of probability distributions, and analysis for runs, range and crossing levels. Time series, event based and regression methods are reviewed. The issues discussed are applied to tree-ring analyses, streamflow gaging stations, and digital modeling of small watersheds and the Tucson aquifers.
    • Subsidence Damage in Southern Arizona

      McCauley, Charles A.; Gum, Russell L.; Department of Hydrology and Water Resources, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      Land is subsiding over a heavily mined aquifer in south central Arizona. Subsidence damages are inventoried to help provide a basis upon which cost studies can be performed to determine actions to lessen the economic impact of these damages. Water table drawdown produces increasing loading stress by three ways: changes in bouyant support of aquifer grains, changes in water table, or both. Two types of subsidence are recognized--one-directional compression, and near surface phenomenon. Damages due to natural structures, and to man-made structures are reviewed. Agricultural damages include field releveling, ditch repair and well damage. Damages to transportational facilities include highways, bridges, pipelines, and railroads. Damages to domestic and urban structures are suggested. Questionnaires, interviews and on-site inspections were used to collect information on land subsidence damages in the study area.
    • Transmissivity Distribution in the Tucson Basin Aquifer

      Supkow, D. J.; Department of Hydrology and Water Resources, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      The distribution of transmissivity within the Tucson basin aquifer, as determined by pumping tests and reviewed in the construction of a digital model of the aquifer, was not totally random in space. Data tended to be distributed normally or log-normally for biased samples of developed wells. A frequency distribution of transmissivity derived from a calibrated digital model is more nearly representative of the real world because the aquifer sample is without bias as the sample constitutes the entire aquifer. Geohydrologic setting, electric analog, and digital models of the basin are discussed. The theory of transmissivity distribution in an arid land alluvial aquifer is developed from Horton's laws of exponential relationship between stream order and drainage network parameters. It is hypothesized that there is an exponential relationship between transmissivity of an alluvial aquifer. A statistical study was made of values derived from the digital model to test the probability density function hypothesized for transmissivity. The mean value is a function of climate and drainage area. These hypotheses require further validation.
    • Water Disposition in Ephemeral Stream Channels

      Sammis, T. W.; Hydrology and Water Resources, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      The contribution of flows from small watersheds to groundwater recharge is of interest. Water disposition depends on infiltration and evaporation characteristics. This study had the objective of developing an infiltration equation for estimating transmission losses during a flow event in an ephemeral stream near Tucson, Arizona, in the rocky mountain forest and range experiment station. Palo Verde, desert hackberry, cholla, marmontea and mesquite are the major bank species of the sandy channels. A climatic section consisting of a hydrothermograph recording rain gage and class a evaporation pan was installed. A water balance method was used to estimate evapotranspiration. A specially designed infiltrometer was used to simulate flow events. The data allowed the following conclusions: Philip's infiltration equation is an excellent mathematical model, initial moisture affects initial infiltration rate, the Philip coefficients are determinable by the infiltrometer constructed, soil moisture affects infiltration rates, and transpiration rates diminish linearly proportional to the ratio of available water to field capacity.
    • Weather Modification in Arizona, 1971

      Osborn, Herbert B.; USDA-ARS Southwest Watershed Research Center, Tucson, Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      There have been many efforts in recent years to modify thunderstorms through cloud seeding. Collective cloud seeding efforts in Arizona before 1971 are reviewed and an operational convective cloud seeding program carried out in Arizona in the summer of 1971 is analyzed. The comprehensive Santa Catalina cloud seeding experiment (1957 to 1964) was a randomized seeding using silver iodide. Results of this experiment are uncertain as numerous interpretations are possible. Numerous individual experiments from 1966 to 1970 at flagstaff were conducted, with uncertain results. An intensive program of seeding individual cumulus clouds with silver iodide was carried out in the summer of 1971 in central and eastern Arizona. No statistically significant changes were noted. Results of the Catalina experiment imply that seeding decreased rainfall on and downwind from the target. Two other experiments were inconclusive. Nine figures show precipitation patterns.