Now showing items 7157-7176 of 15029

    • Hydrologic characteristics of a semiarid watershed

      Woolhiser, David A.,1932-; Mees, Quentin M. (The University of Arizona., 1959)
    • Hydrologic Model Parameterization Using Dynamic Landsat-Based Foliar Cover Estimates for Runoff Simulation on a Semiarid Grassland Watershed

      Guertin, David P.; Kautz, Mark Anderson; Guertin, David P.; Hollifield Collins, Chandra D.; Goodrich, David C.; van Leeuwen, Willem (The University of Arizona., 2016)
      Changes in watershed vegetative cover from natural and anthropogenic causes including, climatic fluctuations, wildfires and land management practices, can result in increased surface water runoff and erosion. Hydrologic models play an important role in the decision support process for managing these landscape alterations. However, model parameterization requires quantified measures of watershed biophysical condition to generate accurate results. These inputs are often obtained from nationally available land cover data sets that are static in terms of vegetation condition and phenology. Obtaining vegetative data for model input of sufficient spatiotemporal resolution for long-term, watershed-scale change analysis has been a challenge. The purpose of this research was to assess the implications of parameterizing the event-based, Rangeland Hydrology and Erosion Model (RHEM) with dynamic, remotely sensed foliar cover data. The study was conducted on a small, instrumented, grassland watershed within the Walnut Gulch Experimental Watershed surrounding Tombstone, Arizona. A time series of foliar cover rasters was produced by calibrating Landsat-based Soil Adjusted Total Vegetation Index (SATVI) scenes with field measurements. Estimates of basal and litter cover were calculated using allometric relationships derived from ground-based transect data. The model was parameterized using these remotely sensed inputs for all recorded runoff events from 1996-2014. Model performance was improved using the remotely sensed foliar cover compared to using an a priori value based on static national land cover classes. Significant (p<0.05) correlation was shown for the linear relationships between foliar cover and SATVI, foliar cover and basal cover, and foliar cover and litter cover. The integration of Landsat-based vegetative data into RHEM shows potential for modelling on a broadened spatiotemporal scale, allowing for improved landscape characterization and the ability to track watershed response to long-term vegetation changes.
    • Hydrologic modeling for watershed erosion control

      Akhbari, Taghi.; Fogel, Martin M. (The University of Arizona., 1978)
      The watershed manager, hydrologist and design engineer are always faced with the problem of taking a particular action and making decision under uncertainty. This report explains and applies a method to be used in the design of floodwater retarding structures, and sediment storage reservoirs and to evaluate the effects of land treatment practices on the watershed hydrographs for ungaged watersheds or where precipitation records are available but streamflow data do not exist. The suggested procedure for estimating runoff hydrograph and sediment yield consists of obtaining parameter estimates from available precipitation data for a probabilistic rainfall model. The model is used to generate two 100-year and 20 ten-year simulation runs of precipitation events through the Monte Carlo procedure. The synthetic records were converted to runoff and sediment yield by means of the Soil Conservation Service equation (rainfall-runoff equation) and the modified universal soil loss equation, respectively. For determining the runoff curve number or hydrologic soil cover complex number for the W-1BX, a stochastic procedure was used. A regression analysis from available data which related rainfall to runoff was run and then through the SCS equation, the curve number was computed. To present the suggested procedure, the flood of July 16, 1975, was used and compared with the computed runoff hydrograph. The computed sediment yield with the proposed flood retarding structure was compared with the computed sediment yield of W-IBX in present condition.
    • Hydrologic modeling to determine the effect of small earthen reservoirs on ephemeral streamflow

      Lovely, Collis Joe,1944-; Cluff, C. Brent (The University of Arizona., 1976)
      Due to the concern of downstream water users, the effect of a large number of small stock water reservoirs on streamflow in North- Central Arizona was studied. The U. S. Department of Agriculture Agricultural Research Service's hydrologic watershed model -- USDAHL-74 Revised Model of Watershed Hydrology, developed by H. R. Holtan, N. C. Lopez, and others -- was used. The 49 square mile study watershed, Red Tank Draw, on the Beaver Creek Experimental Watershed, contains 27 small earthen reservoirs with a total storage capacity of 124 acre-feet which control runoff from 32 percent of the watershed. Average annual runoff for 14 years of record totals 4,192 acre-feet, with a range from 32 to 13,420 acre-feet. Approximately two-thirds (or 2,994 acre-feet) of the total occurs in the winter and spring runoff seasons. Results indicate that during the winter and spring, when the majority of runoff occurs, streamflow at the mouth of the watershed was reduced 2.6 to 10.7 percent for the four years studied. These results are consistent with the results of previous research on other watersheds in which reductions in streamflow due to small reservoirs ranged from 2 to 33 percent. The watershed model, as used in this study, was unable to adequately simulate runoff in low water yield years and during the summer runoff season. The model worked well in simulating the winter and spring runoff periods. Based on the findings of other studies, it did a reasonably good job in evaluating the effects of the reservoirs on streamflow.
    • Hydrologic resource assessment of upper Sabino Creek basin, Pima County, Arizona

      Bales, Roger C.; Peters, Christopher John; Bales, Roger C. (The University of Arizona., 2000)
      A hydrologic resource assessment was performed for upper Sabino Creek basin, using data from a variety of local, state, and Federal agencies and organizations. Hydrologic fluxes were identified and quantified in order to create a monthly water budget. Snowmelt and rainfall are the major inputs to the watershed. Evapotranspiration accounts for the greatest loss of water. Human consumption and streamflow, while important for regulatory and aesthetic reasons, are relatively minor components of the water budget. Evapotranspiration, precipitation, and groundwater recharge I soil moisture account for the greatest fluxes of water in the basin. Precipitation is the most variable hydrologic process in the study area. Over a 47-year period, the greatest amount of water moving through the system in any one month was 6,300 acre-feet in October of 1983. The month with the lowest movement of water was December 1996, with 400 acre-feet. A comparison of Sabino Creek data with the El Nino Southern Oscillation phenomenon shows a strong correlation with precipitation and streamflow in upper Sabino Creek basin.
    • Hydrologic simulation of pinyon-juniper woodlands in Arizona

      Guertin, D. Phillip; Mattern, David Ellis, 1957- (The University of Arizona., 1989)
      A physically-based, user friendly, hydrologic computer simulation model was developed for pinyon-juniper woodland watersheds. The data requirements are minimum, requiring vegetation conditions, basic soil survey information, and daily values for precipitation and temperature. The model predicts runoff from cleared and uncleared watersheds by simulating hydrologic processes on a daily basis. The model was tested with data from small pinyon-juniper watersheds in central Arizona. A crack-forming vertisol was the dominant soil type, and a special feature for addressing its effects on runoff was included. No significant difference between predicted and observed annual runoff was found at the ninety-five percent confidence level.
    • Hydrologic-system analysis of the Wind River Formation with special reference to underground mining in the Shirley Basin area, Wyoming

      Budo, Shoro,1928-; Ferris, J. G.; Harshbarger, John W. (The University of Arizona., 1965)
      The Wind River Formation in the Shirley Basin area of southcentral Wyoming is a series of conglomeratic sand lenses interbedded with clay and silt lenses0 The sediments for the most part are unconsolidated0 Large quantities of ground water are found in the formation under both artesian and water-table conditions0 The sand, silt, and clay sequence forming the upper part of the formation contains water under nonartesian conditions0 The lower ore-bearing sand is an artesian aquifer. The lower sand averages 80 feet in thickness and is overlain and underlain by clay lenses averaging 15 and 50 feet, respectively. The aquifer is bounded on the east by a subsurface ridge formed by the relatively impervious Wall Creek Member of the Frontier Formation (Cretaceous). Pumping tests of the lower sand aquifer indicate that the coefficient of transmissibility ranges from 23, 000 to 29, 000 gpd/ft, and the coefficient of storage ranges from 0 00006 to 0 22. The Thiem and Theis mathematical models used in these computations are limited by a number of assumptions0 One of these assumptions is that the aquifer is infinite0 The Wall Creek ridge is known to limit the extent of the aquifer0 The method of images was used to reproduce the hydrologic control established by this aquifer boundary0 Results of this study indicate that the aquifer characteristics are about 25, 000 gpd/ft for transmissibility and 0 0001 for storage0 Using these values and the appropriate boundary control, the size and shape of the computed drawdown closely approximates the drawdown observed in the field0 The data upon which these results are based are very limited. To further verify the results, exploratory drilling and construction of additional observation wells are recommended0 The results of this additional study should be evaluated before plans for a dewatering pumping regimen are undertaken.
    • Hydrological and mechanical characteristics of soil in the area of salt deposits, northwest Phoenix, Arizona.

      Touqan, Omar Izzat,1941-; Lacy, W. C. (The University of Arizona., 1971)
      The construction of a salt plant northwest of Phoenix, Arizona, after the discovery of a salt dome has caused concern about possible pollution of the agricultural land and groundwater, especially in the presence of subsidence cracks resultant from groundwater withdrawal. Therefore it becomes necessary to study geological and hydrological conditions and hydrological and mechanical characteristics of soil in and around the salt plant. Geologic sections north and south of the ponds show a lithologic sequence from ground surface to 50 feet depth composed of brown silty clay, caliche, brown silty clay with 15 to 20 percent of sand, grey or green silty clay, and sandy, gravelly and silty clay. However, the impression gained from the results of the investigations is that subsidence is the only probable source of pollution from the seepage along the cracks that might cut the ponds. Therefore, an instrumentation program should be set up to monitor any future subsidence due to groundwater withdrawal or future salt mining.
    • Hydrological considerations in locating the proposed Superconducting Supercollider in the Sierrita Mountains, Arizona

      Davis, Stanley N.; Davis, James Paulin Tilton, 1954- (The University of Arizona., 1989)
      The Sierrita Mountains were investigated as a site for the proposed Superconducting Supercollider, which was to be housed in a ring-shaped tunnel more than 80 km (50 miles) in circumference. Geostatistical techniques including kriging were used to interpolate the potentiometric surface of the ground water and quantify its uncertainty along the proposed ring alignment to assess potential dewatering problems, based on the sparse water-level information available. Potential water supplies for the Superconducting Supercollider complex include local and imported good-quality ground water, poorer quality but abundant Central Arizona Project water, and Tucson or Green Valley municipal water. Ground water has the most suitable quality, but its development within the Tucson Active Management Area is restricted by state law.
    • Hydrology and ground water potential of the Tihama-Yemen Arab Republic

      Al-Eryani, Mohamed L. (Mohamed Lotf); Evans, Daniel D. (The University of Arizona., 1979)
      Tihama is Yemen's coastal strip of land bordering the Red Sea. It occupies an area of about 20,000 km² and represents the country's most promising agronomic resource. With a total median annual volume of about 1,000 MCM (million cubic meters), surface water enters the Tihama plain through seven major wadis that drain the mountainous catchments to the east. The Tihama's Quaternary section constitutes the region's only known ground water aquifer. It consists of a thick sequence of alluvial sediments. Ground water occurs under water table conditions, and is annually replenished primarily by seepage of surface runoff. Using the technique of flow net analysis, it was found that annual natural ground water discharge through the Tihama aquifer to the Red Sea amounts to about 300 MCM. A confirmation of this magnitude of discharge was possible by computing two water balances at two of the major wadis. Results of the discharge computations can be applied in the planning of future salvage of this non-beneficial loss. Given that the current system of surface and ground water irrigation in the Tihama supports an area of about 150,000 hectares, a recovery of as little as 50 percent of this loss can increase the irrigated area by an additional 15,000 hectares.
    • Hydrology and ground water potential of the Tihama-Yemen Arab Republic

      Al-Eryani, Mohamed L. (Mohamed Lotf) (The University of Arizona., 1979)
    • The hydrology and plant community relations of Canelo Hills Cienega, an emergent wetland in southeastern Arizona

      Guertin, D. Phillip; Davis, Judith Camisa, 1960- (The University of Arizona., 1993)
      An important wetland type in the southwestern United States requiring study is the cienega. Cienega is a Spanish term used for wetlands found in semi-arid grasslands, associated with perennial springs and headwater streams. A field study was conducted at Canelo Hills Cienega in Southeastern Arizona for one year in which changes in water levels, soil water content, and stream flow were monitored. Plant composition, soil classification, and basic geological characteristics were determined as well. Water level fluctuations and flow gradients indicate that this cienega is mostly groundwater dependent and is an effluent system maintaining the perennial nature of the adjacent stream. Mean water levels ranged from.9 cm above the surface to 0.85 m below. Water level fluctuation within the cienega ranged from 1.12 m/yr to 0.18 m/yr. Vegetation occurred in distinct patterns which varied across the cienega in relation to water levels and availability. Dominant genera included Eleocharis, Carex, Juncus, Poa, and Bidens.
    • The hydrology and riparian restoration of the Bill Williams river basin near Parker, Arizona

      Maddock III, Thomas; Harshman, Celina Anne; Maddock III, Thomas (The University of Arizona., 1993)
    • Hydrology and water resources of Capitol Reef National Park, Utah : with emphasis on the middle Fremont River area

      Christiana, David.; Davis, Stanley N.; Rasmussen, Todd C.; Bassett, Randy L.; Henderson, Norman R. (The University of Arizona., 1991)
      The water resources of the Capitol Reef National Park area include the middle Fremont River, other perennial and ephemeral watercourses, isolated springs, tinajas, and lakes fed by precipitation on surrounding plateaus, as well as ground water in alluvial, basalt, and sedimentary aquifers fed by recharge from precipitation and stream channel losses. The difference between streamflows at Bicknell (79.2 million m³/yr) and Caineville (67.8 million m³/yr) can be attributed to evapotranspiration by riparian vegetation and cultivated crops and ground-water recharge, which exceeds 1.5 million m³/yr. Regional ground-water movement is eastward from Thousand Lake Mountain and southward along the Waterpocket Fold. Ground-water quality is generally brackish while surface water is fresh, both degrading east of the Waterpocket Fold due to agricultural uses, evapotranspiration and long aquifer residence times. Along the middle Fremont River agricultural use causes a mean salt load increase of 16,100 metric tons/year, turbidity increases three-fold, and fecal coliforms generally increase.
    • The hydrology of Aravaipa Creek, southeastern Arizona

      Ellingson, Charles Thurston.; Evans, Daniel D. (The University of Arizona., 1980)
      The hydrologic system responsible for the perennial flow of Aravaipa Creek in southeastern Arizona consists of a basin filled with sediments and ground water. Ground-water flow through the basin sediments converges at the entrance of Aravaipa Canyon where much of it is forced to the surface due to a restriction in the cross-sectional area of the unindurated sediments. By applying Darcy's law, these sediments are found to have a hydraulic conductivity of up to 1,300 feet/day. The data used in the analysis show that Aravaipa Creek attains its full discharge within 2 miles of the canyon entrance due to a gradual reduction in the transmissivity of the sediments. Precipitation over the watershed is divided quantitatively into evapotranspiration, stream discharge, and pumpage. Ten years of streamflow data divided into base flow and storm runoff show that 8,500 acrefeet/ year become base flow due to ground-water runoff from the valley aquifer. Recharge in the Aravaipa aquifer equals discharge. The discharge, Aravaipa Creek base flow plus pumpage, is 11,600 acre-feet/year, or 2.4 percent of total precipitation. Streamflow statistics, water quality, and current water use are documented, and suggestions for further research are made.
    • HYDROLYZED FLUID WHEY IN A YOGURT-TYPE FOOD.

      Wucinich, Regina. (The University of Arizona., 1984)
    • The hydrometallurgical extraction of transition metals from ferromanganese nodules

      Burzminski, Michael Joseph, 1953- (The University of Arizona., 1978)
    • Hydrophobic partitioning of the bacteriophage MS-2

      Bales, Roger C.; Gerba, Charles P.; Kroeger, Thomas William, 1952- (The University of Arizona., 1989)
      In batch experiments at pH's 5 and 7, the partitioning of MS-2 between water and silica (unbonded) was compared with the partitioning between water and silica with 6.5 percent of the surface covered by hydrophobic C18 chains (bonded). The roles of double-layer and van der Waals forces in partitioning were explored by modeling the potential energies of interaction. MS-2 adsorption to unbonded silica was negligible at pH 7, but did occur at pH 5. Adsorption was independent of pH with the bonded silica and approximately 2.6 orders of magnitude greater than the unbonded at pH 5, suggesting the importance of hydrophobic partitioning. The total potential energies of interaction, which closely approach the pH-independent van der Waals potentials, are similar in magnitude for all pH's or silica types, and have no positive (repulsive) values. The insignificant contribution of the double-layer potentials suggests that these pH-dependent forces may not account for the pH-dependent adsorption observed with the unbonded silica.