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The Global ETD Search service is a free service for researchers
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Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 1 to 4 of 4 (0.07 seconds)Spelling suggestions: "subject:"hydrologic systems"" "subject:"hyrdrologic systems""
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Nonpoint-Source Pollutants to Determine Runoff Source AreasLane, L. J., Norton, H. L., Wallace, D. E., Wilson, R. E., Martin, R. D. 16 April 1977 (has links)
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 / Hydrologic information is needed to understand and control water pollution from semiarid rangelands. However, the hydrologic systems under any given conditions must be understood and the effects of various land uses predicted. Based on the concept of partial area response, a runoff tracer study was conducted on two small watersheds. The watersheds were partitioned into four geomorphic subzones or hydrologic response units. Each of the four zones on both watersheds was treated with about 1 kg/ha of an individual water soluble herbicide. Runoff volumes and sources estimated using the tracers were consistent with results from simulation studies. Also, the principle of corresponding runoff and pollutant discharge rates was used to develop two methods of runoff hydrograph estimation from each of the geomorphic subzones. Method 1 matched the mean total concentration and total runoff volume. Method 2 matched the instantaneous total concentration and the instantaneous runoff rate from the entire watershed. Results from the two methods suggested that, although they may be equivalent with respect to runoff volume, Method 2 may be more consistent with respect to peak discharge.
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Design and Pilot Study of an Arizona Water Information SystemFoster, K. E., Johnson, J. D. 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 / Water information systems may have different demands, such as responding to queries about rainfall-runoff relationships, water level data, water quality data and water use. Data required for retrieval may need display, such as a hydrograph. Information systems are reviewed and results of specific water information agencies are reported. Agencies in Arizona are listed with their specific water information need. Development of a water activity file and water information system is outlined for Arizona as a pilot project. Linkage of units within the data system is shown, as is the information system's questionnaire to project leaders. Information currently in the system includes water quality from the state department of health for 450 wells in the Tucson basin, and water level, storage, storage coefficient and transmissivity supplied by the Arizona water commission for the Tucson basin and Avra Valley. Quality of data submitted to the system should be reflected in retrieval for better understanding of the data. This consideration is planned for the coming fiscal year.
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Transmissivity Distribution in the Tucson Basin AquiferSupkow, D. 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 / The distribution of transmissivity within the Tucson basin aquifer, as determined by pumping tests and reviewed in the construction of a digital model of the aquifer, was not totally random in space. Data tended to be distributed normally or log-normally for biased samples of developed wells. A frequency distribution of transmissivity derived from a calibrated digital model is more nearly representative of the real world because the aquifer sample is without bias as the sample constitutes the entire aquifer. Geohydrologic setting, electric analog, and digital models of the basin are discussed. The theory of transmissivity distribution in an arid land alluvial aquifer is developed from Horton's laws of exponential relationship between stream order and drainage network parameters. It is hypothesized that there is an exponential relationship between transmissivity of an alluvial aquifer. A statistical study was made of values derived from the digital model to test the probability density function hypothesized for transmissivity. The mean value is a function of climate and drainage area. These hypotheses require further validation.
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Water Quality Problem of the Urban Area in an Arid Environment, Tucson, ArizonaHansen, G. 15 April 1978 (has links)
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 U.S. Environmental Protection Agency 's two-year 208 area-wide Water Quality Management Study for Pima County, Arizona, is discussed in terms of the specific problems of municipal wastewater effluent, industrial wastewater, urban stormwater runoff, land disposal of residual wastes, septic systems, and construction activities related to the City of Tucson urban area. The primary groundwater and the slow cycling of the hydrologic system in this arid urban environment reduce many water pollution problems to insignificant levels in the short term, (2) there does exist significant long-term pollution problems in the area. These problems include urban stormwater runoff and landfill leachate, and are related to the pollution of groundwater recharge and aquifer water supplies, and (3) there is a strong need for total water resource planning in arid urban areas which includes planning for wastewater reuse, water harvesting, and proper management of groundwater recharge systems.
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