Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 113-117).

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1987. / Includes bibliographical references (leaves 149-151).

Thesis (M. S. - Soil, Water and Environmental Science)--University of Arizona, 1999. / Includes bibliographical references (leaves 91-94).

Thesis (Ph.D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 219-230).

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 111-120).

Thesis (Ph. D.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Orientador: Rodrigo Lilla Manzione / Resumo: A recarga é um parâmetro necessário para o sistema de gestão em recursos hídricos como subsídio ao controle de outorga e planos de bacia. Apesar disso, a dinâmica de recarga das águas subterrâneas contém alta complexidade e sua quantificação é de difícil obtenção quando comparada com medições de águas superficiais, que conta com métodos mais acessíveis. Contudo, através da utilização de modelagens, foi possível progredir em metodologias para solucionar ou estimar as informações referentes ao recurso hídrico subterrâneo. Uma das metodologias mais aplicadas para o cálculo da recarga em aquíferos livres é o método Water Table Fluctuation (WTF), que estima o valor da recarga através da variação de nível do aquífero e com dados de precipitação local. Assim foi realizado o cálculo da estimativa de recarga da área de afloramento do Aquífero Guarani, no Estado de São Paulo, município de Bofete. Os valores de recarga de aquífero encontrados foram em torno de 30% a 48% das precipitações, mostrando a relação das águas meteóricas com as subterrâneas. Os resultados foram discutidos no escopo da integração da recarga das águas subterrâneas nos planos de bacia, mostrado como essa informação pode ser utilizada por agências reguladoras e comitês de bacias. / Abstract: Groundwater recharge is a necessary parameter for water resources management as the foundation for giving water use rigths and watershed management plans. Unfortunately, groundwater dynamics are highly complex and its quantification is difficult to obtain as compared to surface water, which can use more accessible methods. However, through the use of models, it is possible to use multiple methodologies to determine information on groundwater resources. One of the most applied methodologies for calculating the recharge of unconfined aquifers is the Water Table Fluctuation (WTF) method, which can be used to calculate the level variation of the aquifer using local precipitation data. In the state of São Paulo in the municipality of Bofete, the accumulation of the recharge area of the Guarani Aquifer was calculated. The aquifer recharge values were found to be around 30% to 48% of the total precipitation, showing the relation between the meteorical water and the groundwater. The results were discussed in the scope of groundwater recharge integration in watershed plans, showing how this information can be used by regulatory agencies and watershed committees. / Mestre

The Saline Valley Conservancy District (SVCD) formed in 1980 to provide groundwater to communities in Saline and Gallatin, Counties, Illinois. Sulfate contamination from a nearby coal mine threatens the SVCD’s current well field. Three of the wells are reaching the end of their service and have elevated levels of sulfate. This study investigated multiple well configurations on three different parcels of land to find possible new well locations that do not recharge water directly from the mine site over a 50-year period. A steady-state finite difference groundwater flow model was created using Graphic Groundwater GIS (Krienert and Esling, 2016), a pre and post-processor for MODFLOW (Harbaugh, 2005) and MODPATH (Pollock, 2012). The calibration and sensitivity analysis followed methods from Esling et al. (2008). Hydraulic heads were calibrated to the land surface and a systematic sensitivity analysis varied recharge, hydraulic conductivity, and drain and river conductance to produce composite capture zones. Well locations must also meet SVCD requirements that would minimize distance from current water lines and consider properties they already owned. New wells also needed to be located in areas where the aquifer exceeds 25 m thick and be separated by 305 meters to minimize drawdown. This study also considered the effects of irrigation on the aquifer. Varying recharge, hydraulic conductivity and conductance within reasonable ranges created six capture zones for the proposed wells, each with different geometries. The capture zones were superimposed onto a map to make a composite capture zone which should contain the actual capture zone for the wells. Varying conductance caused subtle changes in capture zone geometry. Low values of conductance caused particle tracks to elongate. Irrigation wells and some proposed well locations caused substantial dewatering in one area of the aquifer. The study discovered several well configurations on each of the parcels that do not source water from the mine site over 50 years.

Groundwater is considered a reliable resource, relatively insensitive to seasonal or even multi-year climatic variation, however quantifying aquifer-scale estimates of stress in diverse hydrologic environments is particularly difficult due to data scarcity and the limited number of techniques in deriving stress parameters, such as use and availability, which can be applied over a large spatial area. The scope of this project is to derive aquifer-scale estimates of annual volumes for groundwater withdrawal, recharge, and groundwater’s contribution to environmental flows as a means to provide screening level estimates of aquifer-scale stress using the groundwater footprint. British Columbia (BC) has mapped and classified more than 1100 aquifers, but the level of development for each aquifer has always been subjectively based on well density or the anecdotal knowledge of groundwater use. Sectoral groundwater use is critical for local regions and aquifer-scale groundwater stress studies which are significantly impacted by changes in the groundwater use nominator. Results suggest that BC uses a total of ~562 million cubic meters of groundwater annually. The largest annual groundwater use by major sectors is agriculture (38%), finfish aquaculture (21%), industrial (16%), municipal water distribution systems (15%), and domestic private well users (11%). Estimating recharge uses multi-scale methods to examine the recharge mechanisms and provide a more reliable recharge estimate in complex mountainous terrain. Local-scale recharge was estimated using the water table fluctuation (WTF) method outlined by Cuthbert (2014). Aquifer-scale recharge was quantified using a quasi-2D water balance model and generalized aquifer parameters of soil and aquifer material, regional climate, and water table depth. Regional scale aquifer recharge was attributed the areal average recharge flux modelled by the global hydrologic model, PCR-GLOBWB. Results show that generally recharge predictably varies with precipitation and that the average recharge is 791 mm for the local-scale method, 462 mm (32% of precipitation) for the aquifer-scale and 393 mm (33%) for the global hydrologic model. This study estimates groundwater’s contribution to environmental flows across the province for this first time using two separate approaches. The first approach uses the groundwater presumptive standard, which is a general standard for managing groundwater pumping. The second method introduces a novel approach for estimating the contribution of groundwater to environmental flows using the existing environmental flow needs framework and an understanding of low flow zone hydrology. In general, both methods show larger contributions from groundwater to environmental flows in the Lower Mainland and southern Vancouver Island compared to the Interior. For each aquifer, the groundwater footprint (expressed as the unitless ratio of groundwater footprint to aquifer area) is calculated four times; using results from each of the two methods used to estimate recharge and each of the two methods used to estimate the groundwater contribution to environmental flows. Of the unconfined aquifers (n = 404) in the province, 43 aquifers (11%) are stressed with high certainty, 32 aquifers (8%) are stressed with low certainty, 296 aquifers (70%) are less stressed, and 29 aquifers (11%) were not included due to missing parameters or issues where modelled recharge was less than environmental flows. / Graduate / 2019-10-25