From the Proceedings of the 1972 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 5-6, 1972, Prescott, Arizona / 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.

From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / This paper describes a water supply data base being developed for the Colorado River Basin States by the University of Arizona under contract with the Electric Power Research Institute, Inc. This data base is a guide to existing natural, technical, economic, and legal water data and water data agencies in the states of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming.

From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / With the advent of ever -increasing energy needs, large-scale surface mining has gained new impetus, and there is much concern about reclaiming the mine spoils to bring about beneficial land uses. This paper presents a decision making algorithm labeled PROTRADE, and a case study of the Black Mesa region in Northern Arizona. PROTRADE considers a set of objective functions, a set of physical constraints, articulates the preferences of the decision maker in a progressive manner, and generates a set of alternative solutions. The decision maker is then able to trade level of achievement, for each objective function, against the probability of achieving that level.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / The compartmented reservoir is presented as an efficient method of storing water in areas of Arizona having a relatively flat terrain where there is a significant water loss through evaporation. The flat terrain makes it difficult to avoid large surface- area-to-water-volume ratios when using a conventional reservoir. Large water losses through evaporation can be reduced by compartmentalizing shallow impervious reservoirs and in flat terrain concentrating water by pumping it from one compartment to another. Concentrating the water reduces the surface-area-to-water-volume ratio to a minimum, thus decreasing evaporation losses by reducing both the temperature and exposure of the water to the atmosphere. Portable, high-capacity pumps make the method economical for small reservoirs as well as for relatively large reservoirs. Further, the amount of water available for beneficial consumption is usually more than the amount of water pumped for concentration. A Compartmented Reservoir Optimization Program (CROP-76) has been developed for selecting the optimal design configuration. The program has been utilized in designing several systems including several in Arizona. Through the use of the model, the interrelationship of the parameters have been determined. These parameters are volume, area, depth, and slope of the embankment around each compartment. These parameters interface with the parameters describing rainfall and hydrologic characteristics of the watershed. The water -yield model used in CROP-76 requires inputs of watershed area, daily precipitation and daily and maximum depletion. In addition, three sets of seasonal modifying coefficients are required either through calibration or estimated by an experienced hydrologist. The model can determine runoff from two types of watersheds, a natural and /or treated catchment. Additional inputs of CROP-76 are the surface water evaporation rate and the amount and type of consumptive use.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / Sediment is widely recognized as a significant pollutant affecting water quality. To assess the impact of land use and management practices upon sediment yield from upland areas, it is necessary to predict erosion and sediment yield as functions of runoff, soil characteristics such as erodibility, and watershed characteristics. The combined runoff-erosion process on upland areas was modeled as overland flow on a plane, with rill and interrill erosion. Solutions to the model were previously obtained for sediment concentration in overland flow, and the combined runoff-erosion model was tested using observed runoff and sediment data. In this paper, the equations are integrated to produce a relationship between volume of runoff and total sediment yield for a given storm. The sediment yield equation is linear in runoff volume, but nonlinear in distance and, thus, watershed area. Parameters of the sediment yield equation include the hydraulic resistance parameter, rill and interrill erodibility terms, and flow depth-detachment coefficient and exponent.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / Surface mining of coal in the western U.S. can cause problems of increased salinity and heavy metal contamination in runoff along with a lack of enough rainfall to sustain plant growth for reclamation. To facilitate the planning of reclamation efforts in such areas results are described of a water quality sampling experiment on the ponds and runoff at the University of Arizona Experimental Watershed on Black Mesa in northern Arizona. A systems theoretic framework is employed to model the watershed and the results of a computer simulation based on this model is used to indicate that salinity buildup could be expected over time, given a minimal change in watershed configuration, with possible development of fluoride contamination being of particular concern. Water quality tests of the pond water and runoff on Black Mesa indicated that the water is within Federal standards for drinking and irrigation, except for sodium and fluoride. It is suggested that if it is economically desirable, the collection of more data on the ponds could be used to develop a simulation model of pond subsystems along the lines of the methodology outlined in this analysis.

From the Proceedings of the 1982 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 24,1982, Tempe, Arizona / A prototypical computer simulation model has been developed to aid watershed managers in estimating impacts of alternative land management practices on nutrient and heavy metal losses due to transported sediment on forested watersheds of the southwestern United States. The model, called SEDCON, allows users at remote locations with modest computer terminal equipment and commonly available data to obtain reliable estimates of nutrient and heavy metal concentrations in suspended sediment originating on uniformly-stocked, forested watersheds in the Southwest. SEDCON has been structured in an interactive mode to facilitate its use by persons not familiar with computer operations. Written in FORTRAN IV computer language, the model requires approximately 5000 words of core. SEDCON is operative on a DEC-10 computer at the University of Arizona.