From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / Sediment production from two chaparral watersheds in central Arizona during a period of heavy winter rainfall in 1978 was compared with sediment production over a 14-year period (1964-78). Results indicate sediment production from chaparral is primarily the result of seasonal periods of heavy precipitation and runoff and not from ephemeral summer rainstorms. Sediments from 300 acres (122 ha) above a newly constructed stock watering tank were produced within a few days time in the late winter of 1978 at an accelerated annual rate of 41.1 ft /acre (2.9 m /ha). The sediments came mostly from cutting in channel alluvium in upstream tributaries where the sediments are presumed to have accumulated from downslope creep, dry ravel, and overland flow produced by ephemeral, convective rainstorms. The accelerated rate of sediment production was more than 4 times the average annual rate of 9.8 ft /acre (0.7 m /ha) determined from 14 years of cumulative sediment deposits in a stock tank constructed in 1964.

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / Small differences can be very accurately measured with two sensors if precautions are taken to periodically interchange the sensors between observations. The Bowen ratio model of evapotranspiration requires measurements of air temperature and humidity gradients near the evaporating surface. The gradients are in the order of only 0.1 °C/m or 10 Pa/m. Precision in excess of 0.01 °C/m or 1 Pa/m can be obtained only through laborious calibration and replication of instruments, or through periodic interchange. The design of a simple system for interchanging psychrometers is described. The system will exchange sensors between two levels one meter apart at selected time intervals. The vertical exchange path of this design maintains a constant orientation of the sensors and has important advantages over rotating systems used elsewhere. The principles apply to a variety of measurement problems.

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / A multiattribute utility function is used to model preferences on outcomes of alternative reclamation schemes for stripmined lands, using Arizona and Wyoming examples. Each scheme should at least help restore land to its premining value, and is composed of three sets of actions: mining operations, preparations for postmining land use, and mitigating actions. Grazing and runoff augmentation are examples of postmining land use goals, and mitigating actions may be measures to protect the environment like pollution control in runoff or infiltration. Conflicting objectives are involved, including the maintenance of sufficient coal production, the alleviation of detrimental environmental effects, and the minimization of loss. Since the environmental effects are fraught with uncertainty, a multiobjective decision-making scheme under uncertainty is set up to analyze the problem. The decision model ranks alternative reclamation schemes on the basis of the preference function of a group decision maker, each member of which assessing a separate subset of single attribute utility functions.

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona / There is a renewed interest in land application of treated effluent in both the states of Arizona and Nevada. Conservation of water and energy can be obtained by this treatment method. Data generated by the design engineer includes health effects related to heavy metals, bacteria, and aerosal spray. Examples of recent nuisance and consequences are noted. The application of this practice requires a case by case engineering and management analysis.

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona

From the Proceedings of the 1979 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona - Nevada Academy of Science - April 13,1979, Tempe, Arizona