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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the 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.
21

Impacts of estimating recharge on groundwater modeling for arid basins

Huffman, Janelle H. Yelderman, Joe C. January 2005 (has links)
Thesis (M.S.)--Baylor University, 2005. / Includes bibliographical references (p. 48-50).
22

Action of autochthonous bacteria on the decay of enteric viruses in groundwater /

Wall, Katrina. January 1900 (has links)
Thesis (Ph.D.)--Murdoch University, 2006. / Thesis submitted to the Division of Science and Engineering. Includes bibliographical references (leaves 148-163)
23

Dissolved noble gases in groundwater

Cey, Bradley Donald, 1974- 20 September 2012 (has links)
Atmospheric noble gases (He, Ne, Ar, Kr, and Xe) dissolved in groundwater are a valuable tool in hydrology. Numerous studies have relied on groundwater recharge temperatures calculated from dissolved noble gas data (noble gas temperatures, NGT) to infer paleoclimate conditions. This research investigated gas dissolution during groundwater recharge and critically examined the use of dissolved noble gas data in groundwater research. A detailed investigation of an agriculturally impacted shallow aquifer allowed comparison of measured water table temperatures (WTT) with calculated NGT. Results suggest that NGT calculated from widely used noble gas interpretive models do reflect measured WTT, supporting the use of dissolved noble gases to deduce recharge temperatures. Samples having dissolved gas concentrations below the equilibrium concentration with respect to atmospheric pressure were attributed to denitrification induced gas stripping in the saturated zone. Modeling indicated that minor degassing (<10% [Delta]Ne) may cause underestimation of groundwater recharge temperature by up to 2 °C. In another study a large dissolved noble gas data set (905 samples) from California was analyzed. Noble gas modeling using the same interpretive models indicates that multiple models may fit measured data within measurement uncertainty, suggesting that goodness-of-fit is not a robust indicator of model appropriateness. A unique aspect of this study was the high Ne and excess air concentrations associated with surficial artificial recharge facilities. A final study examined whether climatic/hydrologic changes occurring over glacial-interglacial time periods could impact the accuracy of NGT used in paleoclimate studies. Numerical modeling experiments estimated WTT sensitivity to changes in: 1) precipitation amount, 2) water table depth, and 3) air temperature. Precipitation and water table depth had a minor impact on WTT (~0.2 °C). In contrast, the impact of air temperature changes on WTT was more pronounced. Results suggest that air temperatures inferred from NGT data may underestimate actual air temperature change since the last glacial maximum by ~1 °C at sites having seasonal snowcover. These results suggest despite uncertainty in the exact physical processes controlling gas dissolution during groundwater recharge, NGT do reflect WTT. However, inferring paleo-air temperatures from NGT are subject to error, especially locations with seasonal snowcover. / text
24

El Obeid Water Supply/Water Harvesting Potential in Western Sudan: Report to Western Sudan Agricultural Research Project, Washington State University, College of Agriculture & Home Economics

Cluff, C. Brent 10 1900 (has links)
Introduction: A trip was taken from July 3 to July 17, 1985 to Sudan to study the El Obeid compartmented reservoir system. This system supplies most of the domestic water for the city of El Obeid which has a population of 200,000 to 250,000 people. This water supply was exhausted in March of 1985 and the town was out of water until the monsoon rains began July 2, 1985. Approximately one week was spent in El Obeid and Kadugli. The remainder of the time was spent in Khartoum where the IBM PC was used. Some time was also spent in Khartoum in obtaining flattened ceramic spheres for evaporation control.
25

Artificial Ground Water Recharge at Litchfield Ranch, Arizona (Preliminary Report Subject to Revision)

Maddox, George E., Jorden, Roger M., Cluff, C. Brent, Resnick, Sol D. 01 June 1960 (has links)
No description available.
26

Estimation of Recharge in a Small Southern Arizona Basin by Means of Hydrological, Hydrochemical, and Environmental Isotope Data

Neuman, Shlomo P., Adar, Eilon 12 1900 (has links)
Estimation of recharge in a small southern Arizona basin by means of hydrological, hydrochemical, and environmental isotope data / A completion report for the Office of Water Research and Technology, U.S. Department of the Interior, Project No. A-099-ARIZ, Grant No. 14-34-0001-1103 / Principal Investigator: Shlomo P. Neuman, by Eilon Adar / December 1983
27

Analysis of well losses pertaining to artificial recharge.

Osborne, Paul Stephen. January 1969 (has links) (PDF)
Thesis (M.S.)--University of Arizona, 1969. / Partially funded by U.S. Dept. of the Interior, Office of Saline Water, under research grant no. 14-01-0001-630. Includes bibliographical references (leaves 92-94).
28

Assessment of vadose zone modeling in a semi-arid region, Nebraska, USA

Wang, Tiejun. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Sept. 18, 2008). PDF text: ix, 228 p. : ill. (some col.) , maps (some col.) ; 4 Mb. UMI publication number: AAT 3297902. Includes bibliographical references. Also available in microfilm and microfiche formats.
29

Dissolved noble gases in groundwater

Cey, Bradley Donald, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.
30

Exploring the influence of land-use and climate on regional hydrology and groundwater recharge

Jayawickreme, Dushmantha Helapriya. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Geological Sciences, 2008. / David Hyndman, dissertation advisor--From acknowledgments. Title from PDF t.p. (viewed on Aug. 20, 2009) Includes bibliographical references (p. 148-150). Also issued in print.

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