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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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Networked Digital Library of Theses and Dissertations.
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 61 to 64 of 64 (0.064 seconds)Spelling suggestions: "subject:"arid bands"" "subject:"arid hands""
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Water Disposition in Ephemeral Stream ChannelsSammis, T. W. 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 contribution of flows from small watersheds to groundwater recharge is of interest. Water disposition depends on infiltration and evaporation characteristics. This study had the objective of developing an infiltration equation for estimating transmission losses during a flow event in an ephemeral stream near Tucson, Arizona, in the rocky mountain forest and range experiment station. Palo Verde, desert hackberry, cholla, marmontea and mesquite are the major bank species of the sandy channels. A climatic section consisting of a hydrothermograph recording rain gage and class a evaporation pan was installed. A water balance method was used to estimate evapotranspiration. A specially designed infiltrometer was used to simulate flow events. The data allowed the following conclusions: Philip's infiltration equation is an excellent mathematical model, initial moisture affects initial infiltration rate, the Philip coefficients are determinable by the infiltrometer constructed, soil moisture affects infiltration rates, and transpiration rates diminish linearly proportional to the ratio of available water to field capacity.
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A Rational Water Policy for Desert CitiesMatlock, W. G. 20 April 1974 (has links)
From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, Arizona / Four sources of water supply for desert cities are rainfall, runoff, groundwater, and imported water, and the potential use for each varies. The government can institute various policy changes to eliminate or reduce the imbalance between water supply and demand. Restrictions should be placed on water-use luxuries such as swimming pools, subdivision lakes, fountains, etc. Water pricing should be progressive; each unit of increased use above a reasonable minimum should be charged for at an increasing rate. Runoff from individual properties, homes, storage, and supermarkets should be minimized through the use of onsite recharge wells, and various collection methods should be initiated. A campaign to acquaint the general public with a new water policy must be inaugurated.
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Reducing Phreatophyte TranspirationDavenport, David C. 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 / Transpiration rates (T) of riparian phreatophytes can be high. Antitranspirant (AT) sprays can curtail T without the ecological imbalance made by eradication. Saltcedar (Tamarix sp.) and cottonwood (Populus sp.) in 15-gal. drums enabled replicated trials on isolated plants or on canopies. T of isolate saltcedar plants could be 2x that of plants in a fairly dense canopy. T for a unit ground area of saltcedar varied from 2.2 (sparse -) to 15.8 (dense-stand) mm/day in July at Davis. Extrapolation of experimental T data to field sites must, therefore, be made carefully. Wax -based ATs increased foliar diffusive resistance (R), and reduced T of saltcedar and cottonwood 32-38% initially and 10% after 3 weeks. R increased naturally in the afternoon when evaporative demand was high and if soil water was low. Nocturnal T of salt cedar was 10% of day T. AT effectiveness increased with a higher ratio of day: night hours, and with lower soil water stress. Therefore, AT will be most effective on long summer days in riparian areas where ground water is available.
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Hydrology as a Science?Dvoracek, M. J., Evans, D. 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 / Experimental and historical development of the systematic study of water is briefly reviewed to prove hydrology a science. The hydrology program at the university of Arizona is outlined, and details of the course 'water and the environment' are expounded. This introductory course is intended for non-scientific oriented students at this southwestern university. A reading list is provided for the class, and scientifically designed laboratory experiments are developed. The first semester includes discussion of world water inventory; occurrence of water; hydrologic cycle; interaction of oceanography, meteorology, geology, biology, glaciology, geomorphology and soils; properties of water (physical, biological, chemical), and resources development. The second semester discusses municipal, industrial and agricultural water requirements, surface, ground, imported and effluent water resources management; water law; economic, legal, political, and social water resource planning; ecological impact; patterns of use; and survival of man. Mathematical problems are reviewed along with ecological orientation of students.
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