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1	Objective and Subjective Analysis of Transition Probabilities of Monthly Flow on an Ephemeral Stream Dvoranchik, William, Duckstein, Lucien, Kisiel, Chester C. 06 May 1972 (has links) 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 / 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. Hydrology -- Arizona. Water resources development -- Arizona. Hydrology -- Southwestern states. Analysis Probability Monthly Ephemeral streams Statistical methods Watershed management Stochastic processes Daily hydrographs Streamflow forecasting Model studies Digital computers Simulation analysis Regulation Arizona Arid lands
2	Nitrogen Species Transformations of Sewage Effluent Releases in a Desert Stream Channel Sebenik, P. G., Cluff, C. B., DeCook, K. J. 06 May 1972 (has links) 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 / A preliminary study was made with the objective of examining nitrogen species transformations of treated sewage effluent releases within the channel of an ephemeral stream, the Santa Cruz River of southern Arizona. Water quality samples were taken at established locations in sequence so that peak daily flows could be traced as the effluent moved downstream. Results indicate that increased nitrification, coinciding with changing stream characteristics, starts in the vicinity of Cortaro Road (6.3 river miles from the Tucson Sewage Treatment Plant discharge). Through physical-chemical changes in streamflow, nitrate -nitrogen values reach a maximum at approximately 90-95 percent and 60-80 percent of total flow distance for low flows and high flows, respectively. Concentrations of ammonia-nitrogen and total nitrogen decrease continuously downstream with both high and low flows. Therefore, the rate of nitrification within sewage effluent releases in a desert stream channel evidently is related to flow distance and physical characteristics of the stream. Hydrology -- Arizona. Water resources development -- Arizona. Hydrology -- Southwestern states. Nitrogen cycle Sewage effluents Ephemeral streams Arid lands Water pollution Arizona Effluent Streams Surface waters Sewage treatment Irrigation water Water sampling Daily hydrographs Nitrification Stream stablization Rates Groundwater recharge Surface-groundwater relationships

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Objective and Subjective Analysis of Transition Probabilities of Monthly Flow on an Ephemeral Stream

Nitrogen Species Transformations of Sewage Effluent Releases in a Desert Stream Channel