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1
Jayawickreme, Dushmantha Helapriya. "Exploring the influence of land-use and climate on regional hydrology and groundwater recharge." Diss., Connect to online resource - MSU authorized users, 2008.
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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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Waibel, Michael Scott. "Model Analysis of the Hydrologic Response to Climate Change in the Upper Deschutes Basin, Oregon." PDXScholar, 2010. https://pdxscholar.library.pdx.edu/open_access_etds/45.
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Considerable interest lies in understanding the hydrologic response to climate change in the upper Deschutes Basin, particularly as it relates to groundwater fed streams. Much of the precipitation occurring in the recharge zone falls as snow. Consequently, the timing of runoff and recharge depend on accumulation and melting of the snowpack. Numerical modeling can provide insights into evolving hydrologic system response for resource management consideration. A daily mass and energy balance model known as the Deep Percolation Model (DPM) was developed for the basin in the 1990s. This model uses spatially distributed data and is driven with daily climate data to calculate both daily and monthly mass and energy balance for the major components of the hydrologic budget across the basin. Previously historical daily climate data from weather stations in the basin was used to drive the model. Now we use the University of Washington Climate Impact Group's 1/16th degree daily downscaled climate data to drive the DPM for forecasting until the end of the 21st century. The downscaled climate data is comprised from the mean of eight GCM simulations well suited to the Pacific Northwest. Furthermore, there are low emission and high emission scenarios associated with each ensemble member leading to two distinct means. For the entire basin progressing into the 21st century, output from the DPM using both emission scenarios as a forcing show changes in the timing of runoff and recharge as well as significant reductions in snowpack. Although the DPM calculated amounts of recharge and runoff varies between the emission scenario of the ensemble under consideration, all model output shows loss of the spring snowmelt runoff / recharge peak as time progresses. The response of the groundwater system to changing in the time and amount of recharge varies spatially. Short flow paths in the upper part of the basin are potentially more sensitive to the change in seasonality. However, geologic controls on the system cause this signal to attenuate as it propagates into the lower portions of the basin. This scale-dependent variation to the response of the groundwater system to changes in seasonality and magnitude of recharge is explored by applying DPM calculated recharge to an existing regional groundwater flow model.
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Konteatis, C. A. C. "Groundwater recharge studies." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381163.
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Murray, Alexander J. "Modeling Artificial Groundwater Recharge in the Santa Rosa Creek Watershed." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2140.
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The Santa Rosa Creek Watershed is an approximately 48 mi2 large watershed located on the central coast of California. This watershed drains to the Pacific Ocean through Santa Rosa Creek as it passes through agricultural land and the town of Cambria. Historically the groundwater within the Santa Rosa Creek Watershed has been used for irrigation, municipal and domestic uses, and the creek is critical habitat steelhead trout. During dry years, there is less water for all uses. When low groundwater levels occur, water can be drawn out of the creek and into the soil, drying out steelhead habitat. Seven agricultural operators within the Santa Rosa Creek Watershed are working with a local non-profit to improve sustainability of the aquifer through artificial groundwater recharge. One of these projects includes the use of a recharge basin. This study was conducted to understand the impacts of that recharge basin on the groundwater surrounding it as well as to evaluate the site’s potential for other recharge methods. The groundwater within the site of interest was modeled using GMS to calculate head values, to determine flow directions, and to determine timings. Three different hydrogeologic layers were used to simulate an upper unconfined zone, a clay confining layer, and a confined zone. The model was calibrated to known groundwater head values throughout the site. ArcMap was used to organize and preprocess data that went into the GMS model. Elevation, hydrologic soil characteristics, boundary heads, recharge rates, evapotranspiration rates, and well locations and pumping rates datasets were all preprocessed and imported into GMS. The model showed that the water from the recharge basin does not percolate into the underlying groundwater aquifer, but it flows out of the upper unconfined layer and into the creek over time. This is caused primarily by a low hydrologic conductivity confined aquifer in the northern section of the site as well as a confining clay layer underneath the unconfined top layer. According to the model, the site may not be feasible for artificial groundwater recharge in the northern portion, but there is potential for recharge in the southern area. Further data collection could improve the model to support or dispute these findings.
5
Miller, Cynthia Jean 1961. "Impact of artificial recharge on Tucson area groundwater quality." Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/278038.
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Results of chemical analyses revealed elevated levels of organic surrogate parameters which included dissolved organic carbon, trihalomethanes, total organic halides, and UV absorbance in Tucson groundwater impacted by artificial recharge activity. Inorganic parameters associated with recharge water were also elevated in Tucson groundwater impacted by artificial recharge. The mobility of organochlorine during deep well injection of chlorinated Colorado River Water into the Las Vegas Valley aquifer was also investigated. The Las Vegas Valley aquifer was found to have little sorptive capacity for organo-chlorine.
6
Pimentel, da Silva Luciene. "Large-scale hydrological modelling : physical parameterisation for groundwater recharge." Thesis, University of Newcastle Upon Tyne, 1997. http://hdl.handle.net/10443/1034.
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There is currently worldwide interest in the effect of human activity on tile global environment, especially the effect of greenhouse gases and land-use change on the global climate, and models are being developed to study both global change and the local effects of global change. The research reported here (funded by CNPq-Brazil) involves the development of GRASP:Groundwater Recharge modelling Approach with a Scaling up Procedure. GRASP has been integrated into the UP (Upscaled Physically-based) macromodel, developed under the UK NERC TIGER programme, which is designed for studying the effects of climate and land-use change on the availability and quality of water resources. The UP macromodel will be coupled to the UK Meteorological. Office's Unified (weather and climate) model to create a state-of-the-art coupled atmospheric/hydrological model. Several important requirements for the design of new large-scale hydrological models are identified in a wide ranging review on GCMs; (General Circulation Models) and physically -based hydrological modelling, and these requirements have been applied in the development of GRASP(and UP). The main requirements are a physical basis, proper treatment of spatial variability, and simplicity. Using the concept of partial analysis, two point-scale models, SM (Soil Moisture content approach) and TF (Transfer Function approach), are developed for recharge, both based on the one-dimensional Richards' equation. SM is a simple two-parameter model relating recharge to water storage in the unsaturated zone, and several unsuccessful attempts are made to link its parameters to physical propcrties. TF is a transfer function model, and is parameterised using the matric potential and unsaturated hydraulic conductivity functions using a new approach developed especially for GRASP. Both SM and TF are verified against numerical solutions of Richards' equation.
7
Parissopoulos, George. "Numerical studies of unsaturated-saturated groundwater recharge from ephemeral flows." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47609.
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Guldan, Nathan M. "Relationships between groundwater recharge dates, nitrate levels, and denitrification in a central Wisconsin watershed /." Link to Abstract, 2004. http://epapers.uwsp.edu/abstracts/2004/Guldan.pdf.
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Kimblin, Richard Thomas. "Groundwater-sediment reactions in the North London aquifer system, with specific reference to artificial groundwater recharge." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315876.
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Bockgård, Niclas. "Groundwater Recharge in Crystalline Bedrock : Processes, Estimation, and Modelling." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4573.
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Kunskap om grundvattenbildningen är nödvändig för att man ska kunna förutsäga konsekvenserna av grundvattenuttag och underjordsbyggande. Grundvattenbildningen i berggrunden är dock svår att uppskatta. Syftet med avhandlingen var att öka förståelsen av grundvattenbildningen i kristallin berggrund, att undersöka hur grundvattenbildningen ska uppskattas samt att utveckla nya modeller för att beskriva grundvattenbildningen. Studien grundades på tre angreppssätt: grundvattendatering med freoner (CFC), geohydrauliska observationer och matematisk modellering.
Koncentrationerna av CFC-11 och CFC-113 befanns vara låga i det undersökta berggrundvattnet, vilket i kombination med låga syrgashalter tyder på anaerob nedbrytning. Koncentrationerna av CFC-12 och tritium överensstämde ganska väl, vilket betyder att den skenbara åldern kan vara den sanna åldern. Resultaten tyder på att CFC-datering inte är pålitlig i skogsmiljöer med finkornigt jordtäcke.
Vid nederbörd observerades ett snabbt gensvar i den hydrauliska potentialen i den studerade bergakviferen, trots det 10 m mäktiga moräntäcket. En avsevärd del av de observerade potentialvariationerna befanns vara belastningseffekter, som inte innebar någon magasinsförändring eller något vattenflöde. Berggrundens belastningseffektivitet uppskattades, ur potentialens svar på lufttrycksförändringar, till 0,95. Ytbelastningen beräknades från mätningar av lufttryck, vatten i jordtäcket och snö. Omkring 20 % av årstidsvariationen hos den hydrauliska potentialen uppskattades bero på enbart belastningsförändringar. En enkel begreppsmässig modell kunde användas för att simulera den observerade hydrauliska potentialen. För att beskriva enskilda grundvattenbildningstillfällen på bästa sätt var det nödvändigt att ta hänsyn till effekten av ytbelastningen.
Numeriska experiment gjordes med en modell av en jord–bergprofil. När berget modellerades som ett heterogent kontinuum bildades omättade zoner i berget vid stora hydrauliska gradienter. Fenomenet uppträdde i områden där låggenomsläppliga zoner låg uppströms höggenomsläppliga zoner, och ledde till minskad hydraulisk konduktivitet i berget.
Knowledge about the groundwater recharge is essential for the prediction of impacts of groundwater withdrawal and underground construction. Recharge in the bedrock is, however, difficult to estimate. The objectives of this thesis were to increase the understanding of groundwater recharge in crystalline bedrock, to investigate how the recharge could be estimated, and to develop new models to describe the recharge. The study was based on three approaches: groundwater dating using chlorofluorocarbons (CFCs), geohydraulic field measurements, and mathematical modelling.
Low concentrations of CFC-11 and CFC-113 were found in the bedrock groundwater, which in combination with low dissolved-oxygen levels indicated anaerobe degradation. The CFC-12 and tritium concentrations agreed fairly well, which means that apparent ages could be true ages. The results suggest that CFC dating may not be reliable at forested, humid sites covered by fine-grained soil.
A quick response in hydraulic head to precipitation was observed in the studied bedrock, despite the 10-m thick till cover. A substantial portion of observed head variations was found to be loading effects, involving no storage changes or water flow. The loading efficiency of the bedrock was estimated, from the air-pressure response, to be 0.95. The surface loading was calculated from measurements of air pressure, water in the soil, and snow. About 20% of the seasonal variation of the hydraulic head was estimated to be related to loading changes only. A simple conceptual model could be used to simulate the observed hydraulic heads. The loading effect had to be included to properly describe individual recharge events.
Numerical experiments were performed with a soil–bedrock profile. When the rock was modelled as a heterogeneous continuum, unsaturated zones developed at high hydraulic gradients. The phenomenon appeared in areas where low-conductive zones were located upstream of high-conductive zones, decreasing the effective hydraulic conductivity of the material.
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Shelters, Alexandra. "Paradoxical Behavior in Groundwater Levels in Response to Precipitation Events." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright156754517986892.
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Eden, Susanna, and Donald R. Davis. "Deciding to Recharge." Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/615798.
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Public water policy decision making tends to be too complex and dynamic to be
described fully by traditional, rational models. Information intended to improve
decisions often is rendered ineffective by a failure to understand the process. An
alternative, holistic description of how such decisions actually are made is presented here
and illustrated with a case study. The role of information in the process is highlighted.
Development of a Regional Recharge Plan for Tucson, Arizona is analyzed as the case
study.
The description of how decisions are made is based on an image of public water
policy decision making as 1) a structured, nested network of individuals and groups with
connections to their environment through their senses, mediated by their knowledge; and
2) a nonlinear process in which decisions feed back to affect the preferences and
intentions of the people involved, the structure of their interactions, and the environment
in which they operate. The analytical components of this image are 1) the decision
makers, 2) the relevant features of their environment, 3) the structure of their interactions,
and 4) the products or outputs of their deliberations. Policy decisions analyzed by these
components, in contrast to the traditional analysis, disclose a new set of relationships and
suggest a new view of the uses of information.
In context of information use, perhaps the most important output of the decision
process is a shared interpretation of the policy issue. This interpretation sets the
boundaries of the issue and the nature of issue-relevant information. Participants are
unlikely to attend to information incompatible with the shared interpretation. Information
is effective when used to shape the issue interpretation, fill specific gaps identified as
issue-relevant during the process, rationalize choices, and reshape the issue interpretation
as the issue environment evolves.
13
Cherry, Andrea J. "A multi-tracer estimation of groundwater recharge in a glaciofluvial aquifer in southeastern Manitoba." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ48143.pdf.
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Porter, Sandra. "Groundwater/surface water interaction in the Raisin River watershed, near Cornwall, Ontario." Thesis, University of Ottawa (Canada), 1996. http://hdl.handle.net/10393/10133.
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A field study was conducted in 1994 and 1995 to understand the interaction of groundwater and surface water in the Raisin River watershed, near Cornwall, Ontario. The Raisin River lies within an agricultural region which relies heavily on groundwater use. The regional groundwater supply is predominantly from a limestone aquifer which underlies various surficial deposits (primarily glacial till). Groundwater movement appears to be in a southeasterly direction, towards the St. Lawrence River. Seepage meters, mini-piezometers, and a falling head permeameter were used to (i) measure the flux of groundwater into (positive seepage) or out (negative seepage) of the Raisin River, and (ii) measure the hydraulic conductivity of the Raisin River sediments. Measurements were made at thirteen sites within the watershed. To identify the source of groundwater and study processes of streamflow generation during storm runoff, surface water, groundwater, and rainwater samples were collected for environmental isotopes (oxygen-18 and deuterium). Raisin River discharge data were also analysed. Seepage measurements and hydraulic conductivities exhibit significant variability. The coefficients of variation for seepage measurements ranged from 20.3 to 392%, and for hydraulic conductivity from 0 to 161%, depending on the site. Seepage flux ranges from $2.23\times10\sp{-6}$ to $\rm{-}9.82\times10\sp{-9}m\sp3m\sp{-2}s\sp{-1},$ and hydraulic conductivity ranges from 10$\sp{-6}$ to 10$\sp{-9}$ ms$\sp{-1}$ (a negative seepage flux indicates groundwater flow from the aquifer to the river). Environmental isotope analyses indicate that meteoric water is the source of local groundwater with a mean residence time of approximately 4 months. After a storm event, groundwater composed 63% of total stream discharge. The peak response in the river is approximately two days after a storm event. These variables indicate that groundwater/surface water relationships should be taken into account if decisions are made with respect to water quality or quantity. (Abstract shortened by UMI.)
15
Groce-Wright, Nigel C. "Analyzing a 10-Year Cave Drip Record in James Cave, Virginia: Implications for Storage and Recharge in Shallow Appalachian Karst Systems." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/104202.
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Karst aquifers, characterized by soluble rocks such as limestone and dolostone, provide drinking water to 20-25% of the world's population and are thus critical global water sources. However, recent work suggests that rapid alteration of karst aquifers due to the impact of climate change on precipitation patterns may affect recharge to these aquifers.
Much of the research on recharge in karst aquifers has relied on using patterns of spring discharge to quantify recharge. Spring outlets allow for continuous monitoring of discharge from karst aquifers, making them easily accessible monitoring sites. However, because springs can integrate multiple flow paths, it is difficult to rely on spring discharge patterns to get information on where and how karst aquifers are receiving recharge. Monitoring closer to the source of recharge through the measurement of cave drips allows for a more accurate analysis of recharge timing and mechanisms.
In this study, I conducted recession analyses on cave drip hydrographs from a 10-year record (2008-2018) of three drip monitoring stations within James Cave (Pulaski Co., VA) to: 1) examine differences in hydrologic characteristics of the epikarst (the zone of soil and weathered bedrock above a karst aquifer); 2) quantify the storage volume of the epikarst and 3) investigate seasonal, and annual trends in recharge.
Results of recession analysis show heterogeneity in epikarst hydrologic characteristics, reflected by calculations of the recession coefficient, , and storage volume. Calculations of the recession coefficient show subtle differences between the three drip sites, suggestive of spatial heterogeneity in permeability and storage in the overlying epikarst. The storage volume calculations show that during the recharge season (winter- spring), up to 95% of recharge through the unsaturated zone to the cave occurs through rapid pathways (i.e., fractures), and 5% through diffuse pathways (i.e., pores). However, during the recession period (spring-summer), when evapotranspiration is active, recharge through cave drips decreases and occurs predominantly through diffuse flow. Combined, these results underscore the importance of both spatial and temporal characterization of drip rates and other recharge inputs into karst aquifer systems.Master of Science
Karst aquifers, characterized by soluble rocks such as limestone and dolostone, provide drinking water to 20-25% of the world's population and are thus critical global water sources. Recent work suggests that climate change may alter how karst aquifers are recharged; however, few studies have addressed this potential impact. This study expands knowledge of recharge in karst aquifers through analysis of a 10-year record (2008-2018) of three cave drip measuring stations in James Cave (Pulaski Co., VA). I used recession analysis of the cave drip record to investigate temporal trends in recharge and to examine hydrologic characteristics of the epikarst, the zone of soil and weathered bedrock above the cave. Results of this analysis show seasonal patterns in cave drips, with the highest drip rates occurring in the winter and early spring. The analysis also shows spatial differences in hydrologic characteristics of the epikarst. Calculations of the storage volume show during the winter and early spring, up to 95% of recharge to the cave occurs through rapid pathways (i.e., fractures), and 5% occurs through diffuse pathways (pore spaces in the soil and rock). Results of this study underscore the importance of both temporal and spatial characterization of cave drips and other recharge inputs into karst aquifer systems. The information gained from this study will add the body of knowledge on how karst aquifers receive recharge, which will aid in protection and management of these critical drinking water sources.
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Bucklin, Jake. "Isotopic analysis of shallow groundwater of the Clear Creek watershed." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5431.
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The stable isotopic composition of groundwater within a watershed in eastern Iowa was studied in order to understand how water moves through the system. Samples were gathered using multiple observation wells and pore water samplers and then analyzed to determine the δ18O and δ2H of each sample. Shallow pore water is much more variable in its isotopic composition than deeper water and seems to be more greatly affected by evapotranspiration, whereas groundwater below the water table appears to show a stable isotopic signature suggesting the integration of multiple rain events. Other samples of similar depths across the slope of a hill were also used to observe differences across the area. By observing changes over time in the signatures of these samples, it can be seen that the crest of the hill is most greatly influenced by infiltration from precipitation while the side of the hill is influenced more by throughflow. By combining stable isotope analyses, knowledge of the medium through which the water is moving and the general mechanics of a watershed, a more advanced understanding of how water interacts with and moves through the ground can be gained.
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Kennedy, Jeffrey R. "Understanding Infiltration and Groundwater Flow at an Artificial Recharge Facility using Time-lapse Gravity Data." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/605117.
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Groundwater provides a fundamental resource for modern life. Throughout the world, groundwater is managed by storing (recharging) it underground in natural aquifers for future withdrawal and consumptive use. In Arizona, over 4 million people benefit from managed aquifer storage, but little effort is made to track the movement of recharged water through the subsurface. Motivated by current limitations in our ability to monitor percolation and groundwater movement at the scale of a recharge facility, an effort to collect time-lapse gravity data was carried out at the Southern Avra Valley Storage and Recovery Project (SAVSARP) operated by the City of Tucson, Arizona. In addition to collecting water-level data 12 wells, there were three primary gravity experiments: (1) five continuously-recording gravity meters (2 iGrav superconducting gravity meters and 3 gPhone gravity meters) were installed semi-permanently in control buildings adjacent to the recharge basins, (2) absolute gravity measurements were made at nine locations over a 17 month period, and (3) three relative-gravity campaigns were carried out on a network of 70 stations. This large-scale controlled experiment, with known infiltration and pumping rates, resulted in one of the most comprehensive datasets of its kind. Gravity data led to several hydrologic insights, both through direct measurement and modeling. First, the infiltration rate could be estimated accurately based on the initial rate of gravity change during infiltration, regardless of the specific yield. Using two gravity meters, the depth, and therefore speed, of the wetting front beneath a recharge basin was observed, including the time at which the water table was reached. Spatial maps of gravity change from relative gravity surveys show areas where infiltration efficiency is highest, and where groundwater accumulates; storage accumulated preferentially to the west of the recharge basins, away from pumping wells. Such information would be valuable for planning the location of pumping wells at a new facility. Gravity data were useful for calibration of a Modflow-NWT groundwater-flow model using the Unsaturated Zone Flow package to simulate recharge; the reduction in the posterior parameter distribution compared to the a priori estimate was substantial and similar to head data. In contrast to model-simulated head data, model-simulated gravity data were less sensitive to more distant model elements and more effective for calibration of a superposition-type model. Observed head data had a strong regional signal reflecting basin-scale conditions with only minor variation associated with individual recharge basins, and were therefore of limited usefulness for model calibration. Together, the methods developed by the study and interpretations they made possible suggest that gravity data are an effective way to better understand large-scale infiltration and groundwater movement.
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Al-Sabbry, Mohammed Mohammed. "An economic and institutional assessment of groundwater recharge in an arid environment: Tucson Basin case study." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288798.
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The City of Tucson, located in a semi-arid region, faces escalating pressure on its groundwater resources associated with rapid urbanization and population growth over tbe past 50 years. Because of concern that the declining water table will threaten the city's development, bringing water from Colorado River via the Central Arizona Project (CAP) was perceived as the sole solution for Tucson's water problem. As soon as CAP water arrived in Tucson in 1992, its quality provoked a quarrel over its use for potable purposes. A significant outcome of that quarrel was the enactment of the 1995 Consumer Protection Act (CPA). The primary objective of the CPA is to preclude the use of CAP water for drinking purposes at least until year 2000, unless it is treated to achieve the same quality as the groundwater previously supplied. The CPA encourages using CAP water for non-potable purposes and for replenishing Tucson aquifer through recharge. This study examines the economic and institutional issues involved in utilizing CAP water for recharge and non-potable purposes in the Tucson Basin. The economic assessment focuses on the impact of CAP water recharge on the water table, the resulting pumping cost savings, and the concomitant benefits of saving groundwater and of using CAP water instead of reclaimed water. The institutional assessment focuses on the effectiveness of using CAP water in stabilizing groundwater withdrawal and replenishing Tucson's aquifer. Four planning scenarios were designed to measure and compare the costs and benefits with and without CAP water recharge. Cost-Benefit Analysis was utilized to measure recharge costs and benefits and to derive a rough estimate of cost savings from preventing land subsidence. The results indicate that the institutional requirements can be met since one scenario relatively stabilizes groundwater and the two other scenarios will recover it. The economic benefits from reducing pumping cost and saving groundwater are not economically significant. Yet, when combing the use of CAP water for recharge and non-potable purposes, scenario 3 would not only augment the water table, but also demonstrate positive net economic benefits from savings groundwater, decreasing pumping costs and using CAP water instead of reclaimed water.
19
Eden, Susanna. "Deciding to Recharge." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/191242.
Full textAbstract:
Public water policy decision making tends to be too complex and dynamic to be described fully by traditional, rational models. Information intended to improve decisions often is rendered ineffective by a failure to understand the process. An alternative, holistic description of how such decisions actually are made is presented here and illustrated with a case study. The role of information in the process is highlighted. Development of a Regional Recharge Plan for Tucson, Arizona is analyzed as the case study. The description of how decisions are made is based on an image of public water policy decision making as 1) a structured, nested network of individuals and groups with connections to their environment through their senses, mediated by their knowledge; and 2) a nonlinear process in which decisions feed back to affect the preferences and intentions of the people involved, the structure of their interactions, and the environment in which they operate. The analytical components of this image are 1) the decision makers, 2) the relevant features of their environment, 3) the structure of their interactions, and 4) the products or outputs of their deliberations. Policy decisions analyzed by these components, in contrast to the traditional analysis, disclose a new set of relationships and suggest a new view of the uses of information. In context of information use, perhaps the most important output of the decision process is a shared interpretation of the policy issue. This interpretation sets the boundaries of the issue and the nature of issue-relevant information. Participants are unlikely to attend to information incompatible with the shared interpretation. Information is effective when used to shape the issue interpretation, fill specific gaps identified as issue-relevant during the process, rationalize choices, and reshape the issue interpretation as the issue environment evolves.
20
Chavez, Rodriguez Adolfo 1951. "Modeling mountain-front recharge to regional aquifers." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/191124.
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The estimation of mountain-front recharge to regional aquifers is approached from a hydroclimatic standpoint. Analytical models of the seasonal water yield and streamflow are developed in this dissertation. These models are specialized for hard-rock mountainous watersheds where deep percolation occurs through fractures exclusively. Input variables are considered to be stochastic, and a relationship between precipitation and surface runoff is derived by using a deterministic physical process. Streamflow models for the summer and winter rainy seasons are developed separately in terms of known parameters of the storm process and unknown parameters of the physical process. The winter model considers the generation of surface runoff from both rainfall and snowmelt. These models include the long-term effective subsurface outflow from the mountainous watershed, or mountain-front recharge, as one of the parameters to be identified. The parameter estimation problem is posed in the framework of maximum likelihood theory, where prior information about the model parameters and a suitable weighting scheme for the error terms in the estimation criterion are included. The issues of model and parameter identifiability, uniqueness and stability are addressed, and strategies to mitigate identifiability problems in our modeling are discussed. Finally, the seasonal streamflow models are applied to three mountainous watersheds in the Tucson basin, and maximum likelihood estimates of mountain-front recharge and other model and statistical parameters are obtained. The analysis of estimation errors is performed in both the eigenspace and the original space of the parameters.
21
Safaei, Jazi Ramin. "Simulation of Groundwater Flow System in Sand- Lick Watershed, Boone County, West Virginia (Numerical Modeling Approach)." Thesis, Kent State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1555300.
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Determining the hydraulic properties of aquifer and aquitards (K,T,and S) is very important in hydrogeologic studies. These parameters can be identified by methods such as laboratory permeability and borehole hydraulic response test. Because these approaches are sometimes costly, involving drilling test holes, and often may not be feasible, numerical modeling approaches can be considered as alternatives. In the following study, numerical modeling is applied to simulate groundwater flow system to determine the hydraulic properties of a weathered/fractured zone in a valley located within the Appalachian Plateau Geomorphic Province. The Appalachian Plateau is characterized by relatively flat-laying but intensely eroded bedrock, comprising cyclical sequences of Pennsylvanian age sedimentary bedrock dominated by sandstone, siltstone, shale, coal, claystone, and occasionally limestone. Fractured/weathered sandstone is potentially the main bedrock groundwater transmitting formation. The extent of fractures is from the ground surface to about 120-150 ft (or roughly 30-40m) under the ground surface. The main groundwater flow occurs from within the intergranular pore space through fractures and along bedding planes of the bedrock.
The water level at a perennial stream in the valley can be considered as the phreatic ground-water level. Therefore, the elevation points along this stream may serve as model calibration points. Because the outflow from the valley is almost entirely via the creek, and creek water represents the groundwater level all along the valley, the model is calibrated and verified by the creek water elevations and the amount of water discharging through the valley. The site- specific hydrogeologic interpretation and evaluation technique presented in this study may be very well applicable to the significant portions of the Allegheny Plateau with similar geomorphologic, tectonic and lithologic characteristics.
22
Phraner, Ralph Wilson 1950. "A hydrogeological evaluation and feasibility analysis of artificial groundwater recharge and recovery in eastern Pauba Valley, Riverside County, California." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/278003.
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The Rancho California Water District has an opportunity to conjunctively manage available ground, surface, imported, and reclaimed water resources through a program of artificial recharge and recovery. The site of proposed operations is eastern Pauba Valley, Riverside County, California. Hydrogeological analyses were conducted to identify valley aquifers, evaluate hydraulic properties and quantify ground water storage, movement and yield. Field studies included nine aquifer tests, a survey of well locations and construction of five monitoring wells. All data collected were entered into a computerized Water Resources Information Management System (WRIMS) custom configured for the project. A finite-difference computer simulation model was constructed to evaluate the feasibility and facilities requirements of two alternative recharge and recovery programs. Computer simulation results confirm the feasibility of 9,000 and 18,000 acre feet per year recharge and recovery programs.
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Stewart, Anne M. "Estimation of urban-enhanced infiltration and groundwater recharge, Sierra Vista subbasin, southeast Arizona USA." Thesis, The University of Arizona, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618344.
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This dissertation reports on the methods and results of a three-phased investigation to estimate the annual volume of ephemeral-channel-focused groundwater recharge attributable to urbanization (urban-enhanced groundwater recharge) in the Sierra Vista subwatershed of southeastern Arizona, USA. Results were used to assess a prior estimate.
The first research phase focused on establishment of a study area, installation of a distributed network of runoff gages, gaging for stage, and transforming 2008 stage data into time series of volumetric discharge, using the continuous slope-area method. Stage data were collected for water years 2008 - 2011.
The second research phase used 2008 distributed runoff data with NWS DOPPLER RADAR data to optimize a rainfall-runoff computational model, with the aim of identifying optimal site-specific distributed hydraulic conductivity values and model-predicted infiltration.
The third research phase used the period-of-record runoff stage data to identify study-area ephemeral flow characteristics and to estimate channel-bed infiltration of flow events. Design-storm modeling was used to identify study-area predevelopment ephemeral flow characteristics, given the same storm event. The difference between infiltration volumes calculated for the two cases was attributed to urbanization. Estimated evapotranspiration was abstracted and the final result was equated with study-area-scale urban-enhanced groundwater recharge. These results were scaled up to the Sierra Vista subwatershed: the urban-enhanced contribution to groundwater recharge is estimated to range between 3270 and 3635 cubic decameters (between 2650 and 2945 acre-feet) per year for the period of study. Evapotranspirational losses were developed from estimates made elsewhere in the subwatershed. This, and other sources of uncertainty in the estimates, are discussed and quantified if possible.
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Neff, Kirstin Lynn. "Seasonality of Groundwater Recharge in the Basin and Range Province, Western North America." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/556969.
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Alluvial groundwater systems are an important source of water for communities and biodiverse riparian corridors throughout the arid and semi-arid Basin and Range Geological Province of western North America. These aquifers and their attendant desert streams have been depleted to support a growing population, while projected climate change could lead to more extreme episodes of drought and precipitation in the future. The only source of replenishment to these aquifers is recharge. This dissertation builds upon previous work to characterize and quantify recharge in arid and semi-arid basins by characterizing the intra-annual seasonality of recharge across the Basin and Range Province, and considering how climate change might impact recharge seasonality and volume, as well as fragile riparian corridors that depend on these hydrologic processes. First, the seasonality of recharge in a basin in the sparsely-studied southern extent of the Basin and Range Province is determined using stable water isotopes of seasonal precipitation and groundwater, and geochemical signatures of groundwater and surface water. In northwestern Mexico in the southern reaches of the Basin and Range, recharge is dominated by winter precipitation (69% ± 42%) and occurs primarily in the uplands. Second, isotopically-based estimates of seasonal recharge fractions in basins across the region are compared to identify patterns in recharge seasonality, and used to evaluate a simple water budget-based model for estimating recharge seasonality, the normalized seasonal wetness index (NSWI). Winter precipitation makes up the majority of annual recharge throughout the region, and North American Monsoon (NAM) precipitation has a disproportionately weak impact on recharge. The NSWI does well in estimating recharge seasonality for basins in the northern Basin and Range, but less so in basins that experience NAM precipitation. Third, the seasonal variation in riparian and non-riparian vegetation greenness, represented by the normalized difference vegetation index (NDVI), is characterized in several of the study basins and climatic and hydrologic controls are identified. Temperature was the most significant driver of vegetation greenness, but precipitation and recharge seasonality played a significant role in some basins at some elevations. Major contributions of this work include a better understanding of recharge in a monsoon-dominated basin, the characterization of recharge seasonality at a regional scale, evaluation of an estimation method for recharge seasonality, and an interpretation of the interaction of seasonal hydrologic processes, vegetation dynamics, and climate change.
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Randle, Nicholas Loring. "Simulating Groundwater Flow Through Methanogenic Coal Beds of the Tongue River Watershed." Thesis, The University of Arizona, 2014. http://hdl.handle.net/10150/339053.
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As an effort to gain a better understanding of the processes that enable and sustain coal bed methanogenesis in the western Powder River Basin, a steady-state groundwater flow model using MODFLOW 2005 was constructed. The model covers the middle Tongue River Watershed of north-central Wyoming and southeastern Montana and is comprised of five heterogeneous layers. The model is designed to determine the location of recharge and quantify the volume and velocity of groundwater fluxes to, from and within methanogenic coal beds. Analysis of the model's results indicate a groundwater regime dominated by horizontal flow, with little hydrologic connection between the methanogenic coal beds and the near-surface aquifers and streams. The model predicts only 3.88 cubic feet per seconds (cfs) or 2.17 percent of the total steady state flux within the modeled domain percolates downward to potentially reach the methanogenic coal beds. Most of this downward flux is predicted to occur at the base of the Bighorn Mountains. Additionally, the model predicts that the transit time to and resultant groundwater age within the methanogenic coal beds in the study area is on the order of thousands of years (predicted minimum age of 8,967 years).
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Carrera, Hernández Jaime Jesús. "Spatio-temporal analysis of aquifer recharge and groundwater potentiometric levels in the Basin of Mexico through the development of a regional database and an open source tool for groundwater flow modelling." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18446.
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The Basin of Mexico, where the Mexico City Metropolitan Zone (MCMZ) and its 20 million inhabitants are located, has had a two-sided approach towards water management, as it has struggled to drain the lakes that once covered this region while at the same time it started to transport in water from adjacent basins in the 1950s for water supply. In addition, the large amount of water extracted from the Basin's aquifer has caused drawdown of the groundwater table and consequently, land subsidence which reaches 40 cm/yr in some areas.The inhabitants of the Basin of Mexico, which comprises five different political entities and in which different agencies are in charge of water supply rely on the Basin's aquifer system as its main water supply source. After analyzing the existing water management policies in the Basin, this work suggests that in order to improve water management a regional groundwater flow model is needed. In order to develop this regional model, different tasks need to be fulfilled: a regional database is needed and regional estimates of aquifer recharge are also required. In order to develop a regional hydrogeological database in this area, the use of both a Relational Database Management System (RDBMS) and a Geographic Information System (GIS) is proposed in order to improve regional data management in the study area. Data stored in this new database, the Basin of Mexico Hydrogeological Database (BMHDB) comprises data on climatological, borehole and runoff variables, readily providing information for the development of hydrogeological models.This work presents a daily soil water balance which uses different vegetation and soil types as well as the effect of topography on climatological variables and evapotranspiration used to estimate recharge to the regional aquifer. Through the application of this model, it has been shown that the mountains that enclose the Basin of Mexico are the main recharge areas of the Basin's regional aquifer system. The spatiLa gestion de l'eau dans le bassin de Mexico (où se trouve la zone métropolitaine de la ville de Mexico avec ses 20 millions d'habitants), a eu deux approches opposées: d'abord on a lutté pour vider les lacs qui couvraient cette région auparavant puis dans les années 50 on commencé a importer de l'eau d'autres bassins.De plus, les grandes quantités d'eau extraites de la couche aquifère du bassin ont causé l'abaissement du niveau de la table d'eaux souterraines et par conséquent, l'aisément du terrain jusqu'à 40 cm/année dans quelques secteurs.Les habitants du Bassin de Mexico, qui comprend 5 entités politiques et où plusieurs organismes sont chargés de la gestion de l'eau, obtiennent leur eau essentiellement de l'aquifère. Après analyse des politiques actuelles de gestion de l'eau du bassin, ce travail suggère qu'a fin d'améliorer cette gestion, un modèle régional d'écoulement d'eaux souterraines est nécessaire. A fin de développer ce modèle régional il faut: une base de données hydrogéologiques et des évaluations de la recharge de la couche aquifère. En ce qui concerne la base de données hydrogéologiques régionale, on propose l'utilisation d'une base de données relationnelle et d'un système d'information géographique, ceci a fin d'améliorer la gestion des données. Les données stockées dans cette nouvelle base de données: "Base de Données Hydrogéologiques du Bassin de Mexico" sont des variables climatologiques, de forage et d'écoulement, fournissant aisément des informations pour le développement des modèles hydrogéologiques.Ce travail présente un bilan quotidien de l'eau (qui considère différents types de végétation et de sol ainsi que l'effet de la topographie sur des variables climatologiques et sur l'evapotranspiration) lequel est employé pour estimer la recharge à la couche aquifère régionale. Par l'application de ce modèle, on a montré que les montagnes qui renferment le bassin du Mexique sont les
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Vandemoer, Catherine 1955. "The hydrogeochemistry of recharge processes and implications for water management in the southwestern United States." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/191146.
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A geochemical approach to the evaluation of the chemistry of natural recharge processes in the Tucson basin was used to identify the major minerals controlling the evolution of ground water chemistry and to assess the viability of recharging imported Central Arizona Project water supplies. Well cuttings analyses and water quality samples from over 65 wells in the basin were used as input to the geochemical computer model PATH4 (Helgeson, 1970) and the sequence of aqueous species and mineral production in a recharge reference volume examined. The study reveals that natural processes in the basin lead to the increase in dissolved solids content in ground water over time and the production of secondary minerals such as calcite, calcium montmorillonite, kaolinite and poorly crystallized alumino-silicate phases. Secondary minerals grow into aquifer pore spaces and may, over time, be responsible for the reduction in aquifer porosity and the specific capacity of wells. The recharge of imported Central Arizona Project water will lead to an increase in the dissolved solids content of ground water and may, in certain areas of the basin, lead to the enhanced production of secondary minerals. The use of CAP water as a recharge source must be guided by the geochemical factors which influence the nature and scope of reactions between CAP water and the Tucson aquifer matrix. The study demonstrates the need for and identifies water quality and aquifer matrix criteria for the assessment of sources of recharge water and recharge facility sites. The use of geochemistry as a tool for quantitatively assessing ground water quality is demonstrated.
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Callahan, Michael Kroh. "Groundwater Controls on Physical and Chemical Processes in Streamside Wetlands and Headwater Streams in the Kenai Peninsula, Alaska." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5347.
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For this dissertation I studied groundwater and surface water interactions in the Kenai Lowlands, Alaska. In particular, I examine two important aspects of groundwater and surface water interactions: 1) Groundwater's influence on surface-water temperature; and 2) Groundwater's role in forming hydrologic flow paths that can connect uplands to streamside wetlands and streams. Chapter 2 investigates the controls on stream temperature in salmon-bearing headwater streams in two common hydrogeologic settings: 1) drainage-ways, which are low-gradient streams that flow through broad valleys; and 2) discharge-slopes, which are high gradient streams that flow through narrow valleys. The results from chapter 2 showed significant differences in stream temperatures between the two hydrogeologic settings. Observed stream temperatures were higher in drainage-way sites than in discharge-slope sites, and showed strong correlations as a continuous function with the calculated topographic metric flow-weighted slope. Additionally, modeling results indicated that the potential for groundwater discharge to moderate stream temperature is not equal between the two hydrogeologic settings, with groundwater having a greater moderating effect on stream temperature at the low gradient drainage-way sites. Chapter 3 examines the influence of groundwater on juvenile coho salmon winter habitat along the Anchor River. Two backwater habitats were selected from the larger set of 25 coho overwintering sites from a previous study for an in-depth hydrologic analysis. The results from chapter 3 showed that the type of groundwater discharge (i.e., focused versus diffuse groundwater discharge) can play an important role in determining habitat suitability in these backwater sites. During winter, focused discharge from a local groundwater seep maintained higher surface-water temperatures and higher concentrations of dissolved oxygen compared to the site with more diffuse groundwater discharge. Chapter 4 investigates the linkages along hydrologic flow paths among alder (Alnus spp.) stands, streamside wetlands, and headwater streams. Chapter 4 tested four related hypotheses: 1) groundwater nitrate concentrations are greater along flow paths with alder compared to flow paths without alder; 2) on hillslopes with alder, groundwater nitrate concentrations are highest when alder stands are located near the streamside wetlands at the base of the hillslope; 3) primary production of streamside wetland vegetation is N limited and wetlands are less N limited when alder stands are located nearby along flow paths; and 4) stream reaches at the base of flow paths with alder have higher nitrate concentrations than reaches at the base of flow paths without alder. The results from chapter 4 showed that groundwater nitrate concentrations were highest along flow paths with alder, however no difference was observed between flow paths with alder located near versus alder located further from streamside wetlands. Vegetation had a greater response to N fertilization in streamside wetlands that were connected to flow paths without alder and less when alder stands were near. Finally, higher nitrate concentrations were measured in streams at the base of flow paths with alder. The combined results of this dissertation showed that, in the Kenai Lowlands, groundwater and surface water interactions have a direct influence on the local ecology and that a fundamental understanding of the hydrology can aid in the successful management and protection of this unique and important ecosystem.
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Hartenstine, Sandra A. "Nutrient Standing Stocks and Partitioning in a Forested Coastal Plain Watershed: Groundwater, Stream and Marsh Creek." W&M ScholarWorks, 1991. https://scholarworks.wm.edu/etd/1539617639.
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Young, Stefan J. "Groundwater Model Studying Effects of Existing Recharge Basin and Proposed Subsurface Barrier for a Ranch in Santa Rosa Creek Watershed." DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2294.
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A groundwater model of a 126.2-acre ranch in Cambria, California was expanded upon to analyze the effects of artificial recharge and a subsurface barrier. The ranch lies within the 48mi2 Santa Rosa Creek Watershed along the Central Coast of California. The mainly agricultural watershed outfalls to the Pacific Ocean to its west. Creek Lands Conservation, a non-profit that aims to conserve and restore habitat along the Central Coast, plans to identify projects to restore stream flow during dry seasons in the creek that runs through the Santa Rosa Creek Watershed and to increase artificial groundwater recharge. This study focuses on two of those projects. One project is an existing recharge basin and the other is a subsurface barrier. The objective of this numerical model is to improve upon an existing model by using a longer duration of data to calibrate the model, calibrating the model to hydraulic properties of soil samples that were obtained from the site at various depths, refining elevations of layers through integration of new borehole exploration data, and adding updated and new data such as mountain front recharge and pumping rates. The modeling program used was GMS which allows calculation and determination of heads and flow directions. Within the model, there are three separate layers based on hydrogeological characterization from previous studies. There is an upper unconfined zone, a confining clay layer, and a confined zone. A package within GMS (Groundwater Modeling System) called PEST (i.e., Parameter ESTimation) was used to calibrate the model to known water surface elevations throughout the site. Data such as elevations, head boundaries, stream flow, pumping rates, recharge, evapotranspiration, well locations, and hydraulic properties of the subsurface was processed and incorporated into the overall model in GMS. Recharge rates from the basin were estimated to be 0.1 m/day roughly starting in February and ending in May for each year. The model showed that the confining layer slows down the flow of water from the recharge basin, but it does eventually percolate into the underlying groundwater aquifer before reaching Santa Rosa Creek after a time period of 5 years. The proposed subsurface barrier does reduce travel times of groundwater by roughly a year and helps percolation of water into the confined layer. With the subsurface barrier it was seen that the water held within the confined aquifer increased on average 5,200 m3 each year.
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Woodhouse, Elizabeth Gail. "Perched water in fractured, welded tuff mechanisms of formation and characteristics of recharge /." Diss., The University of Arizona, 1997. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1997_87_sip1_w.pdf&type=application/pdf.
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Lacher, Laurel Jane 1964. "Recharge characteristics of an effluent dominated stream near Tucson, Arizona." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/191199.
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Almost 90% of the treated sewage effluent processed by the two treatment plants serving the greater Tucson area is available for passive recharge through the Santa Cruz River streambed north of Tucson. In the absence of any major disturbance of the effluent channel, the recharge capacity of the streambed materials decreases over time as microbial activity, and possibly suspended sediments settling out of solution, act to clog the surficial sediments under the effluent stream. Effluent stream transmission-loss measurements made over the period from November 1994 to August 1995 provided data used to determine the average vertical hydraulic conductivity of the low-flow channel in the study reach through simulations using the computer model known as KINEROS2. Saturated hydraulic conductivity (KSAT) served as the calibration parameter in the model. The appropriate KSAT value was chosen for each set of field data by matching the observed and simulated downstream hydrographs for the study reach. KSAT values were corrected for viscosity changes resulting from changing average daily surface water temperatures over the study period. Saturated hydraulic conductivity values for the effluent stream channel ranged from a maximum of 37 mm/hr in January, 1995, following several major winter storms, to a minimum of 11 mm/hr in August, 1995, after a nearly six-month interstorm period. The saturated hydraulic conductivity values decay exponentially with time after the last major winter storm. The mathematical model describing this decay may be used to estimate effluent recharge rates under similar future meteorological and climatological conditions.
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Olson, Kevin Laverne 1954, and Kevin Laverne 1954 Olson. "Urban stormwater injection via dry wells in Tucson, Arizona, and its effect on ground-water quality." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/191990.
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My deepest respect and appreciation are extended to Dr. L. Gray Wilson for providing the opportunity to conduct this research, for his advice and assistance during the course of the research, and for his review of and suggestions for improving this manuscript. I would also like to thank Michael Osborn for his assistance. This research was funded by the City of Tucson. The assistance and direction provided by Mt. Bruce Johnson and Mt. Joe Babcock at Tucson Water are gratefully acknowledged. My thanks are also extended to Dr. Daniel D. Evans, Dr. L.G. Wilson, and Dr. Stanley N. Davis for serving on my thesis committee. Bruce Smith's assistance is gratefully acknowledged. Bruce spent two long days with 110-degree temperatures In a parking lot describing the lithology of sediment samples collected during the drilling phase of this research. He also determined the moisture content and particle size distribution on samples collected from the borehole. The assistance of Ralph Marra and Steve Brooks is also gratefully acknowledged. Ralph waded through city and county bureaucracies to determine zoning at each dry-well site. Steve assisted with collecting dry-well settling chamber sediment samples.
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Powers, Matthew. "Cadmium: a xenohormone present in the Rotterdam watershed and its potential influence on foetal femoral development." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1243296636.
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Gunn, Kpoti M. "Potential Impacts of Irrigation Groundwater Withdrawal on Water Resources in the Scippo Creek-Scioto River Watershed (Ohio)." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429888176.
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Choodegowda, Ravikumar B. "Modeling small reservoirs in the Great Plains to estimate overflow and ground-water recharge." Diss., Kansas State University, 2009. http://hdl.handle.net/2097/4610.
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Doctor of PhilosophyDepartment of Biological & Agricultural Engineering
James K. Koelliker
Small reservoirs catch and store water for long periods and they decrease streamflow and increase ground-water recharge. A field monitoring program provided the measured water depth for four years in several reservoirs in the Republican River Basin where there are concerns about their aggregate effects in the basin. The daily water budget operation for one reservoir was developed. Daily seepage rates were estimated by using precipitation, inflow and evaporation which was assumed equal to grass reference evapotranspiration (ET0), that average 120 to 150 cm/yr, along with the measured stage-storage and stage-surface area relationships. Two computer simulation modules, written in FORTRAN 95, were developed to estimate 1) overflow and gross seepage and 2) potential for ground-water recharge underneath the reservoir. Required daily input data are precipitation, ET0, and inflow from the watershed area. Required reservoir site characteristics include stage-storage and stage-surface area relationships, a standard seepage rate (S0) at 14 different levels in the reservoir, soil-water and plant-growth characteristics and a monthly crop-residue factor. The gross seepage module calculates water depth that determines daily overflow, the water-surface area for evaporation and the head of water on the 14 levels to cause seepage losses. If a level is not inundated, seepage is zero. If a level is inundated less than 0.3-m, S0 is used. When the water head (hL) on a level exceeds 0.3 m, the seepage rate (SL) is increased by, SL = S0 * (hL/0.3)0.25. This relationship was chosen after testing several exponent values between 0 and 1. The modules were calibrated on one reservoir and verified on two others in northwestern Kansas. Results showed runoff from the watersheds averaged about 1.2 to 1.6 cm/yr from the average annual precipitation of 46 to 62 cm. The three reservoirs reduced streamflow at the reservoir site by 74 to 97%, but 90 to 95% of the retained runoff was calculated to contribute to ground-water recharge. Several sensitivity analyses for model inputs were done. Results showed that, the ratio of the average annual inflow volume from the watershed area to the reservoir storage volume was the most sensitive input variable tested.
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Carling, Gregory T. "The rate and timing of direct mountain front recharge in an arid environment, Silver Island Mountains, Utah." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2187.pdf.
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Gerner, Alexander. "A novel strategy for estimating groundwater recharge in arid mountain regions and its application to parts of the Jebel Akhdar Mountains (Sultanate of Oman)." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-137045.
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In arid regions, mountain catchments are the major contributor to the total natural water yield. Due to generally low groundwater tables, subsurface underflow - referred to as mountain-front recharge - is important in distinction to the surface runoff at the mountain front. The extent of the groundwater basin is hereby often vague. Approaches to assess mountain-front recharge are mostly based on groundwater data and integrate over time and space. This, however, cannot provide prognostic and time-dependent estimates of subsurface inflow to the adjacent alluvial basin aquifer. Consequently, the proposed strategy builds on rainfall based approaches. Temporal and spatial resolution is in this case mostly limited by data scarcity regarding hydrological characteristics of the catchment area and high-resolution rainfall data. The proposed novel strategy combines three approaches to tackle these challenges. A newly developed conceptual hydrologic model provides time-dependent estimates based on fully distributed monthly rainfall. For distinct response units and seasons, non-linear relationships between rainfall and recharge describe the hydrogeologic response. The derivation of the response functions is based on a mass balance and considers the principal recharge mechanisms. Parameterisation makes use of available expert knowledge on geomorphology and seasonal rainfall characteristics. As an efficient tool to assess uncertainties, fuzzy arithmetic is used for complementary long-term average water balance estimates. This technique allows considering fuzziness in rainfall input, crop water use in mountain oases, and best available assumptions on recharge as portion of rainfall. Uncertainty regarding the potential, albeit unknown extent of groundwater basins is portrayed based on continuous surfaces which represent the degree of membership to a distinct geographical entity (termed as fuzzy regions). Distinct subsets of these fuzzy regions represent potential groundwater basins for water balance assessment. The proposed strategy was applied on the large scale in an arid karst mountain range in northern Oman. The two complementary assessment approaches result in similar ranges of values. They are in good agreement with inversely computed inflow to a steady state groundwater model for the adjacent basin aquifer. The results of the conceptual hydrologic model are confirmed by the plausibility of average recharge rates for distinct response units and seasons. This shows that less intense winter rainfall contributes mainly to groundwater recharge. Uncertainties due to the vague extent of the groundwater basin are about 30 % of the total mean annual value. An option to mitigate this uncertainty is the complementary consideration of adjacent aquifer systems in future studies. Hydrogeologic survey and observation of groundwater levels in the alluvial basin aquifer in near distance to the mountains is a way to underpin these findings in future studies. This recommenddation applies not only to the discussed study area, but also to mountain block systems in generalIn ariden Gebieten haben Gebirgseinzugsgebiete einen wesentlichen Anteil am gesamten natürlichen Wasserdargebot. Aufgrund i. Allg. tief liegender Grundwasserspiegel ist - in Abgrenzung zum Oberflächenabfluss am Gebirgsrand - auch der unterirdische Abstrom (mountain-front recharge) von besonderer Bedeutung. Die Ausdehnung des unterirdischen Einzugsgebiets ist dabei oft vage. Ansätze zur Abschätzung des mountain-front recharge basieren meist auf Grundwasserdaten und integrieren in Zeit und Raum. Damit können allerdings keine prognostischen oder zeitabhängigen Schätzungen für den Zustrom zur benachbarten alluvialen Aquifer gemacht werden. Daher wird im folgenden ein niederschlagsbasierter Ansatz vorgeschlagen. Das vorgeschlagene neue Konzept kombiniert drei Ansätze, um den genannten Herausforderungen zu begegnen. Mit einem neu entwickelten konzeptionellen hydrologischen Modell auf Basis verteilter Niederschläge werden monatliche Werte für die Grundwasserneubildung bereitgestellt. Es basiert auf nicht-linearen Beziehungen zwischen Niederschlag und Grundwasserneubildung für definierte hydrologisch homogene Einheiten und Jahreszeiten. Deren Ableitung basiert auf einer Massenbilanz und berücksichtigt die wesentlichen Neubildungsmechanismen. Die Parametrisierung basiert auf Expertenwissen zu Geomorphologie und Niederschlagscharakteristika. Fuzzy Arithmetik wird zur Berücksichtigung von Unsicherheiten in einer ergänzenden mittleren jährlichen Wasserbilanz verwendet. Damit können Unschärfen im Niederschlagsinput, beim Pflanzenwasserbedarf in Gebirgsoasen und best verfügbaren Schätzungen der Neubildung als Bruchteil des Niederschlags effizient berücksichtigt werden. Mittels kontinuierlicher Oberflächen, die den Grad der Zugehörigkeit zu einer bestimmten geographischen Entität anzeigen (fuzzy regions) werden Unsicherheiten in der räumlichen Ausdehnung der unterirdischen Einzugsgebiete beschrieben. Definierte Teilmengen dieser fuzzy regions werden dann bei den Wasserhaushaltsbetrachtungen als potentielle Grundwassereinzugsgebiete verwendet. Der vorgeschlagene Ansatz wurde in einer ariden, teils verkarsteten Gebirgsregion im Norden des Sultanats Oman angewendet. Die beiden sich ergänzenden Ansätze zur Abschätzung der Grundwasserneubildung ergaben im langjährigen Mittel vergleichbare Werte. Diese stimmten auch gut mit den Ergebnissen einer inversen Grundwassermodellierung überein. Die Plausibilität der Neubildungsraten für bestimmte hydrologisch homogene Einheiten und Jahreszeiten spricht für die Verlässlichkeit der Ergebnisse des konzeptionellen hydrologischen Modells. Offensichtlich tragen insbesondere die weniger intensiven Winterniederschläge wesentlich zur Grundwasserneubildung bei. Die Unsicherheiten bezüglich der Ausdehnung des Grundwassereinzugsgebiets belaufen sich auf ca. 30 % des mittleren jährlichen Dargebots. Die komplementäre Betrachtung benachbarter Grundwassereinzugsgebiete ist ein denkbarer Weg, diese Unsicherheit in Zukunft zu reduzieren. Ein wesentlicher Beitrag um die Ergebnisse dieser Studie zukünftig weiter zu untermauern wären hydrogeologische Erkundung und Beobachtung von Grundwasserständen im alluvialen Aquifer, insbesondere nahe dem Gebirgsrand. Diese Empfehlung gilt über dieses Fallbeispiel hinaus für vergleichbare Systeme, in denen ein Gebirgseinzugsgebiet den Aquifer in der angrenzende Ebene speist
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Lagergren, Hanna. "Kan den hydrologiska modellen S-HYPE användas för att beräkna grundvattennivåer med tillräcklig noggrannhet?" Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-230983.
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Sveriges geologiska undersökning (SGU) ansvarar för den nationella övervakningen av grundvattennivåer. I Grundvattennätet finns drygt 300 mätstationer där grundvattennivåer observeras två gånger varje månad. Grundvattensituationen i Sverige och grundvattenmagasinens fyllnadsgrad presenteras med kartor som konstrueras med data från de uppmätta grundvattennivåerna. För att öka detaljgraden i kartorna syftade detta arbete till att undersöka om beräkningar från den hydrologiska beräkningsmodellen S-HYPE kunde användas för att fylla ut med data där mätningar inte finns tillgängliga. Arbetet utfördes genom korrelationsanalyser mellan uppmätta och beräknade grundvattennivåer för att avgöra noggrannheten i S-HYPEs beräkningar av grundvattennivåer. Korrelationsanalyserna visade vilka egenskaper hos mätstationerna (miljövariabler) som gav upphov till avvikelser mellan beräknade och uppmätta nivåer. Två typer av modellerade grundvattennivåer har jämförts med uppmätta grundvattennivåer i SGUs Grundvattennät; grundvattennivåer som beräknas med avseende på arealandelarna av jordklasser och markanvändningen i varje delavrinningsområde (viktade medelgrundvattennivåer), samt grundvattennivåer som beräknas separat för varje specifik jordklass i ett delavrinningsområde. Resultaten visade att jordartsspecifikt beräknade nivåer gav bättre korrelation med uppmätta nivåer. Vidare analyser visade att S-HYPE beräknade nivåer i jordklassen grovjord med stor osäkerhet och att jordklassen kunde behöva delas upp för att öka modellens noggrannhet. En stark korrelation erhölls med beräknade nivåer i moränjordar där omättade zonen generellt är liten. Alla miljövariabler påverkade korrelationen mer eller mindre. Den känsligaste faktorn var dock den omättade zonens mäktighet, vilket visade sig då beräknade grundvattennivåer från S-HYPE blev för snabbreagerande när avståndet till grundvattennivån var stort. Speciellt tydligt blev det vid snösmältningen på våren då stor grundvattenbildning sker och mycket vatten under kort tid perkolerar till grundvattnet.The geological survey of Sweden (SGU) is responsible for the national monitoring of groundwater levels. In the Groundwater network there are just over 300 stations where groundwater levels are measured twice each month. The groundwater situation in Sweden and the “degree of filling” of groundwater are presented with maps made with data from measured groundwater levels. To increase the amount of information in the maps, this work intended to examine if calculated data from the hydrological model S- HYPE could be used to fill the spatial and temporal gaps where measured data were not available. The work was performed with correlation analyzes to determine the accuracy of the calculated groundwater levels from S-HYPE. Correlation analyses indicated which site characteristics (environmental variables) of the monitoring stations that caused possible deviations in the correlation. Two types of modeled groundwater levels were compared to measured levels; groundwater levels that were calculated with respect to the proportions of soil classes and land uses in each sub-basin (weighted mean groundwater levels), and groundwater levels that were calculated separately for a specific soil class. The results showed that levels calculated for specific soils gave better correlation with measured levels. Further analyzes showed that S- HYPE calculated levels in coarse soils with considerable uncertainty and that this soil class needs to be better defined. A strong correlation was obtained with the calculated levels in till soils. All environmental variables influenced the correlation to some degree. The thickness of the unsaturated zone, however, was the most sensitive factor in the correlation, which was evident because the calculated groundwater levels from S- HYPE were too fast-responding when the groundwater level was deep. This became particularly clear during the spring snowmelt, when groundwater recharge is large, and a large amount of water percolates to the groundwater zone.
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Lyles, Frank. "Climate Change Adaptation for Southern California Groundwater Managers: A Case Study of the Six Basins Aquifer." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/pomona_theses/172.
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Groundwater has been very important to the economic development of Southern California, and will continue to be a crucial resource in the 21st century. However, Climate Change threatens to disrupt many of the physical and economic processes that control the flow of water in and out of aquifers. One groundwater manager, the Six Basins Watermaster in eastern Los Angeles and western San Bernardino Counties, has developed a long-term planning document called the Strategic Plan that mostly fails to address the implications of Climate Change, especially for local water supplies. This thesis presents an in-depth analysis of the Six Basin Watermaster’s Strategic Plan as a case-study of how groundwater managers can improve their planning assumptions to better prepare for Climate Change. It begins with a brief history of how Southern California’s environment influenced the development of the institutions that manage the Six Basins’ groundwater, then provides a physical description of the aquifer itself. The current scientific literature on Climate Change’s expected impacts on California water supplies are summarized, and the implications of these impacts for basin management are highlighted. The Strategic Plan’s projects are evaluated and critiqued in light of these insights, including a need for the Strategic Plan to: explicitly consider Climate Change in its planning assumptions, use decision-making frameworks that account for uncertainty, and prepare for more frequent droughts and floods in the future. Climate Change will have important effects on how Southern California’s groundwater is managed, and the Six Basins Strategic Plan should be revised to better account for these impacts.
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Ayuso, Gabella Maria Neus. "Risk Assessment and Risk Management in Managed Aquifer Recharge and Recycled Water Reuse: The Case of Sabadell." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/379309.
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The increasing practice of water recycling, including or not managed aquifer recharge (MAR), requires to thoroughly assess the risks posed by it in real systems, not only in laboratory and column studies.
The present work has been developed in a case study in Sabadell, Spain. For this site, the treated effluent of the Ripoll River WWTP is discharged into the Ripoll River, thus enhancing the natural infiltration to the alluvial aquifer. Pumping of the groundwater induces a riverbed filtration process (RBF), which is one of types of MAR. The recovered water undergoes further post-treatments, including UV, chlorination and sand filtration. After the post-treatments, the water is used for park irrigation and street cleaning. This site was part of the RECLAIM WATER project, supported by the European Commission and devoted to studying MAR and the use of reclaimed water for it in different locations in Europe, as well as in other countries outside Europe. For Sabadell case study, named “RISMAR” in the present work, a risk assessment and a risk management have been developed. In addition, a quantitative microbial risk assessment (QMRA) has been developed too. QMRA is not as usually applied to recycled water schemes as it is to drinking water ones, and even less to MAR.
In order to develop the risk assessment, it was necessary to gather data on the site. Most of the data used to develop the present work were generated in the framework of the RECLAIM WATER project, and it included not only basic wastewater and surface water regular parameters and microbiological indicators, but also trace compounds, pathogens and antibiotic resistance genes. Other data were available from public institutions and previous works.
The main results of the risk assessment indicate that for the uses considered for the final treated water the risk is low and in some cases medium, with the exception of using the final treated water as drinking water. Currently, this use it is not in place at the site, and it is not expected to be in the near future. The QMRA results additionally indicate that cross-connection, swimming and the immunocompromised population would be in the limit of the acceptable level of risk. Thus, the immunocompromised population should be considered in risk assessments, as the risk for them might be much higher than for the rest of the population. The residual risks that needed to be managed and considered were posed by inorganic compounds, organic compounds, salinity and mobilization of inorganic compounds from the sediments.
Another important result of the work is that the RBF and subsurface treatment proved to be very useful in reducing the risks posed by pathogens, nutrients, organic compounds and particulates. In contraposition, other risks appeared, like the mobilization of inorganic compounds from the aquifer. Then, these positive results support the request by many authors of treating MAR as an additional treatment.
Finally, a risk management plan has been developed, integrating the results of the risk assessment. For this risk management plan, not only the critical control points are identified, as it is typical for risk managements, but the twelve elements of the framework issued by the Australian Government (NRMMC-EPHC–NHMRC, 2009) have been assessed and developed, thus supporting a robust risk management plan. Emphasis is put in corrective and preventive actions for the system, as well as in defining the critical limits, monitoring program and sampling points. Besides, validation is given the importance it has in order to ensure a proper functioning of the system.La regeneració d’aigües és una pràctica cada cop més generalitzada, que pot incloure o no recàrrega artificial d’aqüífers (MAR: Managed Aquifer Recharge), i que requereix una avaluació dels riscs en sistemes reals en ús. L’estudi actual es desenvolupà a Sabadell, Espanya. En aquest cas de MAR la recàrrega de l’aqüífer es realitza a través del llit del riu Ripoll i s’utilitza l’efluent secundari d’una depuradora. L’aigua que posteriorment s’extreu de l’aqüífer passa per un tractament ultraviolat, cloració i filtre de sorra, i s’utilitza per al reg de parcs i neteja de carrers. Aquest sistema formà part del projecte europeu RECLAIM WATER. Al present treball s’ha desenvolupat una avaluació i gestió del risc. A més a més, s’ha fet un estudi del risc probabilístic, cosa habitual en aigües potables però no en aigües regenerades o en MAR. Les dades utilitzades per a l’avaluació del risc es van generar en el marc del projecte RECLAIM WATER. Altres dades es van obtenir d’institucions públiques i altres estudis. L’avaluació del risc per als usos considerats de l’aigua recuperada i tractada indica que aquest és baix i en alguns casos moderat, amb l’excepció de l’ús com a aigua potable, que no es preveu fer a Sabadell. Els riscs residuals que cal considerar i gestionar tenen com a protagonistes els compostos inorgànics, els compostos orgànics i la salinitat. Un altre resultat important a tenir en compte és que la recàrrega a través del llit del riu és un tractament efectiu per a reduir els riscs derivats de patògens, nutrients, compostos orgànics i partícules. Aquest resultat dóna suport a la demanda de molts autors de considerar el MAR com a un tractament més. Finalment, s’ha desenvolupat un pla de gestió del risc, integrant els resultats de l’avaluació del risc. En aquest pla no només s’han identificat els punts de control crític sinó que també s’han avaluat els dotze elements de les Guies Australianes per a la gestió del risc en MAR, fent molt més robust l’estudi. L’èmfasi ha estat posat en les accions correctives i preventives, la definició dels punts de control crític, la monitorització del sistema i els punts de mostreig.
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Miller, Benjamin Verlinden. "The Hydrology of the Carroll Cave-Toronto Springs System: Identifying and Examining Source Mixing through Dye Tracing, Geochemical Monitoring, Seepage Runs, and Statistical Methods." TopSCHOLAR®, 2010. http://digitalcommons.wku.edu/theses/216.
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In karst areas relationships between activities occurring on the surface and the overall health of the subsurface environment are often highly interconnected. However, the complex nature of karst flow systems can often make identification of these connections difficult. Carroll Cave, a large stream cave system located in the central Missouri Ozarks, is known for its biological and speleological significance. A dye tracing project to delineate a Carroll Cave recharge area through dye tracing has identified an area of 18.5 km2 which contributes water to the cave. The water from Thunder River within Carroll Cave was positively traced to eight springs of the thirteen springs at a distributary spring system known as Toronto Springs. Through examination of the geochemistry of the individual springs, differences in water chemistry between the various outlets has become evident. Additional work with YSI Sonde dataloggers and consideration of carbonate chemistry relationships has sought to further define the variations in hydrochemical behavior, thus aiding in the discrimination potential spring sources. Primary sources thought to contribute water to the spring system include Carroll Cave and Wet Glaize Creek, with some minor influence from other losing streams in the vicinity. Seepage runs along Wet Glaize Creek have also identified major losing reaches, in close proximity to structural features, which may contribute water to Toronto Springs. Examination of the measured parameters and derived have identified that Carroll Cave and Wet Glaize Creek are the primary end members for Ca2+, Mg2+, HCO3-, specific conductance, and temperature. Using these parameters a two end member mixing model has been developed which describes the mixing zone setting at Toronto Springs and calculates the average proportions of flow contributions by the end members. By using a multi-proxy approach of dye tracing, seepage runs, and geochemistry for the individual springs, the source waters and pathways for the springs at Toronto Springs have been identified.
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Loizeau, Sébastien. "Amélioration de la compréhension des fonctionnements hydrodynamiques du champ captant de Crépieux-Charmy." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENU010/document.
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Dans un champ captant, comme celui qui alimente l'agglomération lyonnaise, le fonctionnement de chaque « objet » (bassins d'infiltration, puits, rivières, nappe, zone non saturée) et leurs interactions sont complexes et mal connus. Dans un premier temps, une série d'essais d'infiltration à différentes échelles dans un bassin artificiel de réalimentation a permis de mieux appréhender le fonctionnement de cet ouvrage et de chiffrer les paramètres hydrodynamiques de la zone non saturée. Les résultats des interprétations par méthodes numériques fondées sur l'équation de Richards ont montré que les flux infiltrés dans les bassins dépendent principalement de la conductivité hydraulique à saturation d'une couche située directement sous le sable calibré couvrant le fond du bassin, identifiée comme étant moins perméable que la nappe. Cette couche conditionne l'existence d'une zone non saturée. La réalisation d'essais de pompage dans l'aquifère sur les forages d'exploitation et sur un dispositif spécialement mis en place durant ce travail a permis de déterminer les paramètres hydrodynamiques de la nappe. Une analyse des observations et une modélisation conceptuelle en 2D, puis en 3D ont permis d'identifier les mécanismes prépondérants (stratifications, apports et prélèvements) et de simuler correctement à la fois les flux infiltrés dans un des bassins d'infiltration et la remontée de la nappe. A l'échelle d'un bassin, les flux infiltrés sont variables dans le temps, ils dépendent de l'état de colmatage de la surface d'infiltration mais également de la température de l'eau infiltrée et de l'état hydrique initial du sol sous le bassin. Les analyses de sensibilité réalisées avec les modèles mis en place indiquent que la conductivité hydraulique à saturation de l'aquifère, mais également la proximité des conditions aux limites imposées dans la nappe (les rivières et les puits de pompage) influencent de manière prépondérante la remontée de la nappe. Une modélisation 3D d'un autre secteur du champ captant comprenant deux bassins d'infiltration, deux bras de rivière ainsi que des puits de pompage a été réalisée. La condition à la limite imposée sur les rivières est du troisième type en accord avec l'observation d'un sous-écoulement en nappe. Les échanges nappe/rivières sont calés sur des observations à partir d'une chronique de propagation d'une onde de crue dans la nappe. Des piézomètres en flûte de pan, spécifiquement implantés à proximité d'un bassin, ont permis d'observer des différences de charge hydraulique fortes à différents niveaux de l'aquifère lorsque le bassin d'infiltration est en eau. La modélisation 3D est conforme à ces observations. Elle a confirmé l'importance du rôle d'une hétérogénéité de type argilo-sableuse (de conductivité hydraulique à saturation inférieure aux autres lithologies présentes dans l'aquifère) dans les écoulements (direction et flux). Le modèle développé représente correctement les flux infiltrés via les bassins ainsi que les fluctuations de la piézométrie de la nappe. Il permet de vérifier l'inversion des écoulements par rapport aux infiltrations de la rivière, d'identifier les puits alimentés par les bassins d'infiltration et également de mettre en évidence les flux de nappe passant sous la rivièreIn a well field of the Lyon metropolitan area, designed for drinking water supply, behaviour of each object (infiltration basins, wells, rivers, aquifer, and unsaturated zone) and their interactions are complex and not well-known. As a first step, infiltration tests at different spatial scales in one artificial basin were performed to better understand the basin operation and to estimate the hydrodynamic parameters of the unsaturated zone. Results of interpretation, using numerical methods based on Richards equation, reveal that infiltrated basin fluxes mainly depend on saturated hydraulic conductivity of a layer located just below the calibrated sand layer that cover the basin bottom. Indeed this layer has been estimated to be less permeable than the aquifer, which allows the existence of the unsaturated zone below. Pumping tests in the groundwater have been performed using production wells and a well specially implemented during this thesis work in order to estimate aquifer hydrodynamic parameters. Observations analysis and a conceptual modelling, in 2D and then in 3D, lead to a better understanding of the controlling mechanisms (stratification, input and output) and to simulate both basin infiltration rates and water table rise. Considering the whole basin scale, input fluxes are transient, related to the clogging statement of the infiltration area but also to the temperature of inflow water and the initial statement of the soil just below the basin. Sensibility analyses using the models highlight that the amount of the water table rise is mainly influenced by the aquifer saturated hydraulic conductivity and also by the location of imposed boundaries in the aquifer (rivers and pumping wells). The model properly accounts basin inflow fluxes and water table fluctuations. The model is able to verify if flows are reversed in relation to river exchanges, if wells are fed by infiltration basins and it highlights aquifer flows below the river. A 3D modelling has been realised in another area of the well field, comprising two infiltration basins, two river arms and pumping wells. In agreement with underflow in the aquifer, rivers are imposed in the model as third kind boundary conditions. Aquifer and river exchanges are calibrated with observed data of one aquifer flood-wave propagation. Significant differences of hydraulic heads have been observed at different depths of the aquifer using panpipes piezometers, specifically implemented, close to one infiltration basin. Theses differences are closely related to basin operation. These observations are properly calculated by the 3D model. Using the model, the effect of one sandy-clay heterogeneous layer (whose saturated hydraulic conductivity is lower than the ones of other aquifer lithologies) on aquifer flows (direction and flux) is notable. The model properly accounts basin inflow fluxes and water table fluctuations. The model is able to verify if flows are reversed in relation to river exchanges, if wells are fed by infiltration basins and it highlights aquifer flow below the river
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Lecluse, Simon. "Modélisation de l'influence du changement climatique sur la nappe phréatique du Rhin Supérieur." Phd thesis, Université de Strasbourg, 2014. http://tel.archives-ouvertes.fr/tel-01037925.
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Cette recherche vise, dans un premier temps, à améliorer la connaissance du fonctionnement de l'aquifère du Rhin Supérieur entre Bâle et Lauterbourg, sur une période de temps présent (janvier 1986 à décembre 2002), puis, dans un deuxième temps, à évaluer l'impact du changement climatique sur l'aquifère. Pour obtenir ces résultats, nous avons utilisé le modèle hydrogéologique HPP-INV (Chardigny, 1997) pour le calage de différents paramètres par méthode inverse, pour évaluer le fonctionnement de l'aquifère du Rhin Supérieur en temps présent. Ce modèle, associé à un modèle hydrologique que nous avons développé pour l'occasion, nous a permis de calculer les évolutions piézométriques et de débits dans les rivières pour les 2 horizons futurs par rapport la période de temps présent. Nous avons d'abord caractérisé l'aquifère et défini son fonctionnement. Au niveau de la hauteur piézométrique et du débit dans les rivières de plaine, nous avons identifié le mois de février comme le mois des hautes eaux et le mois de septembre comme celui des basses eaux. A l'inverse, le Rhin suit un régime nivo-glaciaire, soit une période d'étiage en hiver et une période de pointe durant l'été. Nous avons également mis en évidence l'importance des échanges nappe-rivières dans le fonctionnement de l'aquifère, qui représentent 59 % du débit entrant et 87 % du débit sortant par rapport à la nappe phréatique. L'impact du changement climatique sur l'aquifère est ensuite étudié selon 3 scénarios d'émission de gaz à effet de serre développés par le GIEC (Groupement d'experts Intergouvernementaux sur l'Evolution du Climat) : un scénario optimiste, un scénario pessimiste et un scénario intermédiaire. Ces 3 scénarios d'émissions de gaz à effet de serre ont permis la création de 9 scénarios météorologiques, utilisés pour les prévisions sur 2 horizons futurs par rapport au temps présent (août 1961 à juillet 2000) : un futur proche (août 2046 à juillet 2065) et un futur lointain (août 2081 à juillet 2098). Nous avons déterminé que pour la période de futur proche, l'évolution piézométrique calculée dépend du scénario météorologique. En effet, certains scénarios prévoient un abaissement non significatif du niveau de la nappe, alors que d'autres prévoient une élévation. Enfin, un dernier prévoit une élévation du niveau de la nappe dans sa moitié Sud et un abaissement dans sa moitié Nord. Pour la période de futur lointain, certaines prévisions présentent un abaissement du niveau de la nappe, plus important pour le scénario climatique le plus pessimiste. Les autres scénarios présentent une élévation globale du niveau de la nappe, très variable selon le scénario météorologique.Concernant le débit dans les rivières, tous les scénarios prévoient la même tendance pour les 2 horizons futurs. Le Rhin présente une diminution du débit estival, soit son débit de pointe, et une augmentation de son débit hivernal, soit son débit d'étiage ; ce phénomène, plus important pour la période de futur lointain que pour la période de futur proche, montre une modification du régime du Rhin vers un régime pluvio-nival. Pour les autres rivières, nous avons observé une diminution du débit d'étiage et une augmentation du débit de pointe, plus importantes pour la période de futur lointain (entre -46% et -8% pour le débit d'étiage, et entre +32% et +94% pour le débit de pointe) que pour la période de futur proche (entre -42% et -6% pour le débit d'étiage, entre +0% et +102% pour le débit de pointe).
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GLEESON, THOMAS. "Groundwater recharge, flow and discharge in a large crystalline watershed." Thesis, 2009. http://hdl.handle.net/1974/1986.
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The objective of this thesis is to constrain the fundamental hydrogeological processes of a large crystalline fractured rock watershed in the Canadian Shield. The fundamental hydrogeological processes of groundwater recharge, flow and discharge are examined individually as well as holistically using a revised conceptual model. The study area is the topographically-subdued Tay River watershed in eastern Ontario where a thin veneer of soil overlies Precambrian crystalline rocks and Paleozoic sediments. Spatial scales from local-scale (100s m2 to 1 km2) to watershed-scale (>100 km2) are examined. Recharge processes are defined using hydrogeological characterization, numerical simulation and isotopic, thermal and hydraulic responses to a snowmelt event. Soil thickness and bedrock transmissivity are highly heterogeneous at the local scale. Cold, 2H depleted snowmelt locally recharged the bedrock aquifer to depths of at least 20 m within two days. This rapid recharge process is localized to areas where the soil is very thin whereas slow recharge is likely widespread. The impact of lineaments on groundwater flow at the watershed-scale is examined using geomatic analysis, hydrogeological characterization, numerical simulation and fracture mapping. Lineaments are interpreted as structural features because the two principal lineament sets are oriented parallel to fracture and fault orientations. The fractured bedrock underlying lineaments generally consists of poorly connected zones of reduced permeability suggesting lineament can be barriers to recharge and flow in this setting. Natural conservative, radioactive, and thermal tracers are integrated with streamflow measurements and a steady-state advective model to delimit the discharge locations and quantify the discharge flux to lakes, wetlands, creeks and the Tay River. The groundwater discharge rate to most surface water bodies is low. Groundwater discharge is distributed across the watershed rather than localized around lineaments or zones of exposed brittle fractures. In the revised conceptual model, recharge is considered two separate processes, groundwater flow is compartmentalized and the discharge flux is considerably lower than porous media watersheds. This thesis provides a better understanding of fundamental hydrogeological processes in a large crystalline fractured rock watershed which impacts the sustainability of water resources and ecology.Thesis (Ph.D, Civil Engineering) -- Queen's University, 2009-07-13 14:51:25.244
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Gaskill, Teresa G. Restom. "Hydrology of forest ecosystems in the Honouliuli Preserve implications for groundwater recharge and watershed restoration /." Thesis, 2004. http://proquest.umi.com/pqdweb?index=0&did=813798261&SrchMode=1&sid=4&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1235092745&clientId=23440.
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Petrides, Jimenez Aristides Crisostomos. "Managed artificial aquifer recharge and hydrological studies in the Walla Walla Basin to improve river and aquifer conditions." Thesis, 2012. http://hdl.handle.net/1957/30292.
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This research project focuses on the Walla Walla River Basin located on the east side of the states of Oregon and Washington, USA. With the support and collaboration of the Walla Walla Basin Watershed Council, this work embraces four research topics. The first topic includes the feasibility study of artificial aquifer recharge in the Walla Walla Basin. Through development and application of a regional hydrological model, a methodology for evaluating locations of artificial aquifer recharge is presented with a test case. The second research topic evaluates the recharge rates observed from pilot test studies of artificial aquifer recharge. Scale dependence of recharge rates should be considered when excessive induced groundwater mounding forms beneath the infiltrating basins. The third topic utilizes groundwater tracers and simulation models to evaluate the hydraulic connection of springs to infiltrating basins of artificial aquifer recharge. Finally, the fourth topic as a proof of a technique, utilizes distributed temperature sensing technology with a pair of black and white coated fiber optic cables to estimate the effective exposure to solar radiation over the Walla Walla River.Graduation date: 2013
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Covina, Timothy Patrick. "Stream-groundwater interactions in a mountain to valley transition impacts on watershed hydrologic response and stream water chemistry /." 2005. http://etd.lib.montana.edu/etd/2005/covino/CovinoT1205.pdf.
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Rahayuningtyas, Christina, and 克麗絲汀. "Improving AVSWAT Streamflow Simulation by Cooperating Groundwater Recharge Prediction in Upstream Lesti Watershed, East Java, Indonesia." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/56593192500799333663.
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碩士國立中央大學
土木工程學系
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Upstream Lesti Watershed is one of the major watershed of East Java of Indonesia and it covers about 380,93 Ha. The basin has enough water resources to meet current demands but there are many challenges including high spatial and temporal variability in precipitation during one year. Good understanding of the water condition is very necessary to know the effect on streamflow of the Lesti river in each sub basin. This study investigated the contribution of sustainable management water resources in the Upstream Lesti Watershed by prediction the recharge of groundwater using water table fluctuation especially in dry season which can cooperating with the performance of the AVSWAT program ( Arc View Soil Water Assesment Tool) model by comparing observed streamflows with simulated streamflows at outlet. The water table fluctuation method from 4 well was used in the Upstream Lesti Watershed to evaluate the seasonal and annual variations in water level rise and to estimate the groundwater prediction (deep aquifer). The results show that annual water level rise with a range of 2800 mm - 5700 mm in 2007; 3900 mm - 4700 mm in 2008; 3200 mm – 5100 mm in 2009, and 2800 mm – 4600 mm in 2010. Based on standard values of specific yield and the measured water level rise, the prediction from area weighted that occur in sub basin 39 outlets in 2007 amounted to 736 mm; in 2008, amounted to 820,9 mm; in 2009 amounted to 786,7 mm, and the lowest was in 2010 are equal to 306,4 mm. Also, the correlation coefficient has a direct positive relationship range 0,7 < R <1 in the while Dv (%) in this study the smaller values of Dv were satisfied with the range of 23.32% - 55.3% in 2007 - 2010.
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Kuo, Kung-Wei, and 郭功偉. "Subsurface Water Movement and Groundwater Recharge of Terraced Paddy Fields in a Watershed-Experimental and Simulation studies." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7qr9n5.
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碩士國立臺北科技大學
土木工程系土木與防災碩士班
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The purpose of this research is to study the infiltration characteristic, the subsurface flow pattern, and the related preferential flow mechanisms of terrace paddy fields in the mountain areas. The experimental terrace paddy field is located in Gongliao District, New Taipei City. The in-situ tests including water requirement rate, double ring experiment, and soil water distribution. The soil textures and hydraulic conductivity is analysed in the laboratory. Based on the field and laboratory data obtained from experimental paddy field, a three-dimensional groundwater model FEMWATER was adopted to simulate subsurface water movement in the terraced paddy field subjected to various soil/water conditions for two adjacent upper and lower terraced blocks. The simulation scenarios including 1) with constant ponding water in both upper and lower blocks, 2) with constant ponding water only in upper block but remained dry condition in lower block, 3) with constant ponding water in both upper and lower blocks, and setting all soil layers to be saturated condition, and 4) with varied ponding water from rainfall were used to simulate the 3D subsurface water flow conditions. Simulation results showed that lateral seepage play an important role in subsurface water flow, which occupied 62%, 66%, 65%, and 60% of total field infiltration water in upper block for scenarios 1~4, respectively. For deep percolation, which can be regarded as groundwater recharge, scenario 1 achieved the highest amount, followed by scenario 4, 2, and 3. Simulation results also indicated that when water seepage into the slop embankment from upper block, downward movement will develop to the slop bottom and flow pattern will change in this area for different scenarios. For scenarios 1 and 4, the flow will converge the lateral seepage from lower block and continuously move downward, however, a portion of water from upper slop embankment will laterally flow into the lower block due to the tension force in scenario 2, and piezometric head difference in scenario 3, which will reduce the groundwater recharge amount compared to scenario 1. In addition, after the more long-term simulation, the scenario 3 will turn out to be unsaturated flow condition, which means the setting for all soil layers to be saturated condition was not suitable for real paddy environment in study site. It’s worth noting that groundwater recharge amount in scenario 4 was approximately 93% of scenario 1, which may due to the extremely high annual rainfall (>5,000mm) in the research area. The result of this research can be taken as reference for formulating future policies on the conservation of terraced paddy fields and the management of water resource.