• 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.
    • Color It Evaporation

      Dvoracek, M. J.; Department of Hydrology and Water Resources, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      Evaporation is a major hydrologic process in arid and semiarid lands. A brief review of evaporation literature indicates that a unique parameter, color, is desirable. Artificially colored water was used in a west Texas experiment to monitor evaporation rate and to note the effect of color on evaporation. Artificially green water had a higher evaporation rate than sewage and runoff. Five different colored waters were studied from 1966 to 1970. Color seems to affect the amount of adsorbed radiation as well as the extent of black radiation. The trend for a higher daily rate of evaporation existed for colored waters except during periods of low air temperature. Seven graphs are presented to support these conclusions.
    • 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.
    • 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.
    • Hydrology as a Science?

      Dvoracek, M. J.; Evans, D. D.; Department of Hydrology and Water Resources, University of Arizona (Arizona-Nevada Academy of Science, 1972-05-06)
      Experimental and historical development of the systematic study of water is briefly reviewed to prove hydrology a science. The hydrology program at the university of Arizona is outlined, and details of the course 'water and the environment' are expounded. This introductory course is intended for non-scientific oriented students at this southwestern university. A reading list is provided for the class, and scientifically designed laboratory experiments are developed. The first semester includes discussion of world water inventory; occurrence of water; hydrologic cycle; interaction of oceanography, meteorology, geology, biology, glaciology, geomorphology and soils; properties of water (physical, biological, chemical), and resources development. The second semester discusses municipal, industrial and agricultural water requirements, surface, ground, imported and effluent water resources management; water law; economic, legal, political, and social water resource planning; ecological impact; patterns of use; and survival of man. Mathematical problems are reviewed along with ecological orientation of students.
    • 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.
    • Significance of Antecedent Soil Moisture to a Semiarid Watershed Rainfall-Runoff Relation

      Chery, D. L., Jr.; Southwest Watershed Research Center, USDA, Agricultural Research Service, Soil and Water Conservation Research Division (Arizona-Nevada Academy of Science, 1972-05-06)
      Numerous reports from the southwest claim that soil moisture prior to rainfall-runoff event has no influence on the resulting flow volumes and peak rates. Runoff occurs from many storms that would not be expected to produce runoff, and an explanation lies in the occurrence of antecedent rains. This hypothesis is tested by dividing runoff events into 2 subsets--one with no rain within the preceding 120 hours, and the other with some rain within the preceding 24 hours--and to test the null hypothesis. The hypothesis was tested with rainfall and runoff data from a 40-acre agricultural research service watershed west of Albuquerque, New Mexico, using the Wilcoxon's rank sum test. Various levels of statistical significance are discussed, and shown graphically, to conclude conclusively that antecedent rainfall influences runoff from a semiarid watershed.
    • Some Legal Problems of Urban Runoff

      Holub, Hugh; College of Law, University of Arizona, Tucson (Arizona-Nevada Academy of Science, 1972-05-06)
      Pressure is being brought to bear on national resources of air, earth, and water in the growing cities in the arid southwest. Legal questions involved in capturing urban runoff and putting it to a beneficial use are examined. Urbanization of a watershed results in a 3 to 5 fold increase in runoff amounts. Legal aspects include tort liability from floods, water rights to the increased flows, land use restrictions along banks and flood plains, condemnation of land for park development and flowage easements, financing problems, zoning applications, and coordination of governmental bodies responsible for parks, storm drainage and related services. Urban runoff is the most obvious legal problem in the tort liability area. It appears feasible to divert small quantities of water from urban wastes for recreational uses which provide flood control benefits. It appears that municipalities could appropriate increased flows caused by urbanization. The ultimate legal questions remain to be resolved by legislation, litigation or extension of the appropriative system.
    • 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.