• Changes in Water Rates and Water Consumption in Tucson, 1974 to 1978

      Griffin, Adrian H.; Wade, James C.; Martin, William E.; University of Arizona (Arizona-Nevada Academy of Science, 1980-04-12)
    • Error Analysis of Evapotranspiration Measurements

      Hartman, Robert K.; University of Arizona (Arizona-Nevada Academy of Science, 1980-04-12)
      This paper examines the effects of random errors in the precision of latent energy estimates from the Bowen ratio model. The analysis identifies improvements in the instrumentation and in the field measurement techniques. Bowen ratio energy budget measurements were made over an extensive stand of mesquite (Prosopis pubescens) in the San Pedro River valley near Mammoth, Arizona. The error analysis indicated mean half -hour 95 percent confidence intervals for latent energy and sensible heat flux of 0.48 ± 0.09 and 0.21 ± 0.09 cal/cm²/min, respectively. A majority of the random error was associated with the temperature and humidity measurements used in the Bowen ratio model. Psychrometer circuitry and calibration procedures were modified to reduce measurement errors. Subsequent Bowen ratio measurements were made over a kochea (Kochea scoparia) pasture adjacent to the Pecos River near Roswell, New Mexico. The improvements were effective in reducing the mean half-hour 95 percent confidence intervals for latent energy and sensible heat flux to 0.27 ± 0.01 and 0.23 ± 0.01 cal/cm²/min, respectively.
    • An Evaluation of Snowmelt Lysimeters in an Arizona Mixed Conifer Stands

      Gottfried, Gerald J.; Ffolliott, Peter F.; USDA Forest Service; University of Arizona (Arizona-Nevada Academy of Science, 1980-04-12)
    • The Importance of Arizona's Wetlands

      Rodiek, Jon; University of Arizona (Arizona-Nevada Academy of Science, 1980-04-12)
    • Infiltration Response to Surface Plant Cover and Soil Invertebrate Population

      McGowan, Isobel R.; University of Arizona (Arizona-Nevada Academy of Science, 1980-04-12)
    • Water Quality Analyses of the Colorado River Corridor of Grand Canyon

      Tunnicliff, Brock; Brickler, Stanley K.; University of Arizona (Arizona-Nevada Academy of Science, 1980-04-12)
      Water quality research of the Colorado River corridor of Grand Canyon examines important relationships between densities of fecal coliform bacteria in surface water and underlying bottom sediments. Surface water sampling alone does not accurately reflect baseline water quality status of natural recreational waters, as sediments often harbor microbial densities in several orders of magnitude of overlying waters. Water-based recreation activities and natural wave and current processes can resuspend sediment and associated microbial populations, including enteric pathogens. Data show significant associations between surface water and bottom sediment microbial populations, demonstrating the importance of a combined sampling approach to water quality analyses.
    • Water-Awareness in Tucson, Arizona: A Case Study

      Buckley, Kebba; University of Arizona (Arizona-Nevada Academy of Science, 1980-04-12)