• 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.
    • 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.
    • 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.
    • 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.
    • 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.
    • The Construction of a Probability Distribution for Rainfall on a Watershed by Simulation

      Williamson, Gary; Davis, Donald Ross; Systems & Industrial Engineering, University of Arizona, Tucson, Arizona 85721 (Arizona-Nevada Academy of Science, 1972-05-06)
      A raingage reading is a sample from the point rainfall population of an area. The actual average rainfall on the area (watershed) is a conditional probability distribution. For the case of thunderstorm rainfall this distribution is simulated by looking at all storms that could have produced the raingage reading. The likelihood of each storm is a function of its center depth. The amount of rain dumped on the watershed by each storm is weighted by the likelihood of its occurence and the totality of such calculations is used to produce a probability distribution of rainfall on the watershed. Examples are given to illustrate the versatility of the program and its possible use in decision analysis.
    • 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.