• Invited Topical Speaker: John D. Hem, Water-Quality Studies Today and Tomorrow

      Hem, John D.; U.S. Geological Survey, Menlo Park, California (Arizona-Nevada Academy of Science, 1973-05-05)
      Development of better instruments for analysis and automation have greatly increased the available information on quality of water during the past decade. There remains a need for further research on relationships between dissolved material and the solids in contact with water in order to cope with existing or potential problems in water quality such as the extent to which lead from automobile exhausts may contaminate water supplies, or the safety of disposal of toxic wastes into deep saline aquifers.
    • Use of Stock Ponds for Hydrologic Research on Southwest Rangelands

      Simanton, J. R.; Osborn, H. B.; USDA, ARS Soil, Water, and Air Sciences; Southwest Rangeland Watershed Research Center, Tucson, Arizona (Arizona-Nevada Academy of Science, 1973-05-05)
      Five livestock watering ponds on the walnut gulch experimental watershed were instrumented to evaluate the use of these ponds as a method for comparing rainfall amounts with runoff sediment volumes. Pond drainage area, vegetative cover, soil type, percent slope, and years of record were tested. Instrumentation consisted of water level recorders, and a topographic survey of each stock pond to ascertain its storage capacity. The results to date have been insufficient to reach definite conclusions due to instrumentation and surveying problems, and because of the natural variability of thunderstorm rainfall. Since most of these problems have now been corrected, future data should yield valuable hydrologic data for semiarid rangelands by means of these instrumented stock ponds.