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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Sistema de suporte a decisão para o lançamento de efluentes. / Decision support system for wastewater discharge and water abstraction rights.

Bonnecarrere Garcia, Joaquin Ignacio 15 April 2011 (has links)
Esta tese desenvolveu um Sistema de Suporte a Decisão para auxiliar na concessão de outorga de lançamento de efluentes, através do qual é possível avaliar estratégias de outorga visando facilitar o processo de análise e a efetivação do instrumento. O SSD utiliza em seu processo de análise algoritmos evolucionários para a otimização do processo de alocação de demanda e de carga efluente, visando a maximização dos usos e a minimização dos custos das medidas de tratamento de efluentes, respeitando os limites estabelecidos pela classe de enquadramento dos corpos dágua. Os algoritmos evolutivos analisados foram os Algoritmos Genéticos, Particle Swarm Optimization e o Differential Evolution. Entre as estratégias de outorga consideradas estão o atendimento da legislação ambiental para o lançamento de efluentes, a isonomia entre os usuários, o atendimento aos padrões de qualidade estabelecidos pelo enquadramento dos corpos hídricos e as restrições impostas pelo órgão gestor aos usuários ou as finalidades de uso. Para avaliar o desempenho do SSD foi realizado um estudo de caso na Bacia Hidrográfica do Rio Atibaia, no Estado de São Paulo. O Rio Atibaia foi escolhido por apresentar problemas de disponibilidade hídrica e conflitos pelo uso da água, o que permite avaliar os resultados do SSD para as diferentes estratégias em um caso real. Os resultados obtidos pelos três algoritmos para as estratégias analisadas foram satisfatórios atendendo as restrições e penalidades impostas à função objetivo. Observou-se que a estratégia de outorga que não considerou a Legislação Ambiental para lançamento de efluentes e a questão da isonomia entre os usuários apresentou o menor custo global das medidas de tratamento de efluentes. Este resultado se deve ao fato desta estratégia ser menos restritiva que as demais analisadas, e pelo melhor aproveitamento da vazão disponível no trecho para diluir os efluentes. As estratégias propostas neste estudo tiveram como principal objetivo avaliar o comportamento do SSD na obtenção das análises, assim como analisar a flexibilidade dos algoritmos na introdução de restrições e penalidades. Para a escolha das estratégias de outorga, destaca-se o importante papel do Comitê de Bacia e do órgão gestor para definir as prioridades, tendo em vista que os critérios de outorga, a legislação ambiental e a isonomia, podem acarretar em investimentos mais elevados para a implementação das medidas de tratamento. O Sistema de Suporte a Decisão proposto nesta tese representa um avanço no processo de gestão de recursos hídricos, uma vez que envolve importantes critérios e estratégias na análise da outorga de direito de uso da água, sem dissociar os aspectos de quantidade e qualidade da água e aspectos econômicos para sua efetivação. / This study presents a Decision Support System (DSS) to assist in the issuing of wastewater discharge and water abstraction rights, including the evaluation of alternative pollution control strategies used to facilitate the analysis and implementation of the instrument. The DSS substantiates its analysis with the use of evolutionary algorithms for the optimization of water demand and wastewater discharge allocation. It intends to maximize the uses and minimize the costs of wastewater treatment measures, according to the limits imposed by the water quality standards. The evolutionary algorithms investigated in this study include Genetic Algorithms, Particle Swarm Optimization and Differential Evolution. Among the strategies considered for the issuing of water rights were the compliance with environmental legislation for wastewater discharge, the equality between water users, the water quality standards et by the water bodies classification, and the restrictions imposed by the responsible controlling agency. The SSD was evaluated on a case study area, at Atibaia River, located in the State of Sao Paulo. The Atibaia River was chosen because of the existence of innumerous conflicts of over water use and availability. It allows the assessment of the SSD performance, to different strategies, in a real case scenario. The SSDs results, using all three introduced algorithms, were satisfactory to the strategies analyzed, as they complied with the restrictions and penalties imposed to the objective function. Strategy one, with no restrictions or penalties, had the lowest overall cost of wastewater treatment measures, in comparison to strategy two, equity between water users, and three, compliance with Environmental Laws. This result is due to the fact that strategy one is less restrictive than the two others, and because of the best use of the available flow, in each respective reach, to dilute the wastewater discharge. The main objective of the proposed strategies is to evaluate the performance of the SSD in getting the results, as well as to analyze the flexibility of the algorithms when new restrictions and penalties are introduced in the decision making process. Water users, other stakeholders and the responsible controlling agency have an important role in the selection of suitable strategies and priorities of uses. Higher investments to implement water treatment measures may become necessary according to the strategy chosen. In addition, when a strategy is not well defined, it may cause unnecessary investments. The DSS proposed in this study represents an advance in water resources management. It involves important criteria and strategies used in the analysis of wastewater discharge and water abstraction rights, without disassociating water quality and quantity aspects as well as economic factors for its implementation.
212

The Mormon Role in Irrigation Beginnings and Diffusions in the Western States: An Historical Geography

Harper, Kelly C. 01 January 1974 (has links)
Irrigation has played an important part in the development of the Western States. Its beginnings have often been associated with the Mormon settlement in Utah. However, irrigation had its inception in the West long before the Mormons came to the Great Basin in 1847. The spatial extent of irrigation before this date included limited acreage in nearly every Western State.Before their arrival in the Great Basin the Mormons had become acquainted with irrigation methods. Knowledge of irrigation had diffused to them primarily from the Spanish in the Southwest. Thus, they were well prepared to begin their irrigation enterprises in the West. After establishing the practice of irrigation securely in Utah, this region then served as a source area from which irrigation methods then diffused to other Western areas.Eventually, the status and influence of Mormon irrigation waned. In more recent years Utah has fallen behind other Western States in total irrigated acreage and in the application of new irrigation technology.
213

High-Frequency Nitrate Monitoring in Dynamic River Systems: the Case of Three Iowa Rivers in the Mississippi Basin

Banerjee, Malini De 01 July 2013 (has links)
High frequency water quality monitoring presents unique and unlimited opportunities of exploring spatio-temporal variation in water quality. Knowledge gained from analyzing high frequency water quality data can provide more clarity regarding transportation and processing of water constituents over time and space and scale. This study analyzes high frequency discharge, nitrate load and concentration data for three watersheds of different sizes - Cedar River Watershed, North Raccoon and Middle Raccoon. Each of these sites were monitored for 2-3 calendar years. Sudden spikes in discharge, nitrate concentration and load data, also defined as "events" were analyzed in great detail to understand the patterns in event occurrence and event intensity. Smaller watersheds seemed to have sharper and "flashier" events compared to bigger watersheds. Nitrate concentration events were flatter in shape compared to discharge and nitrogen load events. The relationship between nitrogen concentration and discharge was found to be varying over time, unlike the relationship between nitrate load and discharge, which were almost perfectly correlated for most site-year combinations. Based on more than 40,000 simulations, it was determined that high frequency water quality sampling is not only efficient in capturing minute spatio-temporal variations but can also capture nitrate exceedances to a greater degree. High frequency sampling was also associated with higher yield ratio in nitrate load estimates, not only during high flow periods, but also during the non-high-flow period.
214

Measuring Inorganic Carbon Fluxes from Carbonate Mineral Weathering from Large River Basins: The Ohio River Basin

Singer, Autumn B 01 July 2017 (has links)
Rising atmospheric CO2 concentrations have motivated efforts to better quantify reservoirs and fluxes of Earth’s carbon. Of these fluxes from the atmosphere, one that has received relatively little attention is the atmospheric carbon sink associated with carbonate mineral dissolution. Osterhoudt (2014) and Salley (2016) explored new normalization techniques to improve and standardize a process for measuring this flux over large river basins. The present research extends this work to the 490,600 km2 Ohio River drainage basin and 11 subbasins. The study estimated the DIC flux leaving these basins between October 1, 2013, and September 30, 2014, based on secondary hydrogeochemical, geologic, and climatic data. The total annual DIC flux for the Ohio River basin was estimated to be 7.54 x 1012 g carbon (C). The time-volume normalized value of DIC flux for the Ohio basin was 3.36 x 108 g C/km3 day, where the km3 refers to the amount of water available during the year. This was within 71.4% agreement with the Barren River data (Salley, 2016) and within 63.9% agreement with the Green River data (Osterhoudt, 2014). In general, normalized DIC flux values of sub-basins containing at least modest amounts (more than 8%) of exposed carbonates (Tennessee, Cumberland, Green, Kentucky, Licking, Monongahela, and Allegheny) were in strong agreement with the normalized DIC flux of the Ohio River basin, whereas inclusion of basins with little or no near surface carbonates (Wabash, Great Miami, Scioto and Kanawha) yielded poor agreement. Regression analysis yielded strong agreement between DIC flux and the normalization parameters for the carbonate-bearing sub-basins (R2 = 0.97, p =
215

Longitudinal Thermal and Solute Dynamics in Regulated Rivers

Haider, Muhammad Rezaul 01 December 2017 (has links)
Dam releases increase river stage and can reverse groundwater movement into and out of the river. As the flood, thermal, and solute waves travel downstream in a regulated river, the size of the waves is anticipated to be affected both by river processes and exchanges with near river groundwater. This study established a modeling framework to quantify the influences of the groundwater exchanges on the temperatures and solute concentration dynamics along regulated rivers. The wave properties, volume of exchanges, conservative solute mass exchanges, and heat energy exchanges were calculated as a function of time and distance downstream. Results show that the temperature and solute concentrations are influenced by the arrival of flood waves. Groundwater exchanges were found to affect temperatures along the river with a minimal effect on solute concentration. These findings provide insight regarding the influences of hydropeaking occurring in a large fraction of rivers in the world which has important implications for water quality and the ecology of regulated rivers.
216

An Urban Karst Aquifer Resource Evaluation and Monitoring Toolbox

Kaiser, Rachel Anne 01 July 2019 (has links)
In urban karst areas, such as the City of Bowling Green, Kentucky and the Tampa Bay Metropolitan Area, groundwater quality faces a variety of threats. The development of residential, commercial, and industrial landuse types allows for a wide variety of groundwater pollutants to enter the karst groundwater systems. Various different models and indices have attempted evaluative approaches to identify issues in urban karst areas, but the methods vary by location and lack a focus on urban karst groundwater quality. There also exists a lack of a data-driven approach that is able to capture short- and long-term changes in threats to groundwater quality as a result of urbanization. The overall purpose of this study was to develop a holistic, data-driven evaluation toolbox with threat, vulnerability, and monitoring assessment tools for urban karst groundwater systems to better determine the possible threats, data collection needs, monitoring parameters, and analytical approaches needed to ensure groundwater quality is maintained in urban karst regions. This study focused on: 1) determining what indicators, parameters, resolution, and data quality need to be prioritized to create an effective, holistic monitoring framework for urban karst groundwater, and 2) developing an effective assessment and evaluative tools for urban karst groundwater quality sites using historic and modern data in an urban karst setting. The outcomes include an Urban Karst Aquifer Resource Evaluation (UKARE) Toolbox with a Threat, Vulnerability, and Monitoring evaluation tools that were applied and validated through application of the Toolbox using case studies in the City of Bowling Green, Kentucky and the Tampa Bay Metropolitan Area in Florida. The results demonstrate the universal applicability of the UKARE Toolbox to different urban karst sites and its effectiveness at scoring for threats and vulnerabilities, as well as identifying potential monitoring sites through primary data collection of water quality parameters and emerging pathogens at over 150 sites between both study areas. The final results of this study are useful to develop monitoring and management plans through a standardized scoring and evaluation tool in order to influence urban karst groundwater monitoring and management.
217

ANALYSIS OF DROUGHT ASSOCIATED IMPACTS ON THE CITY OF SAN BERNARDINO MUNICIPAL WATER DEPARTMENT’S WASTEWATER FLOW RATES AND CONSTITUENT CONCENTRATIONS

Budicin, Anthony Nicholas 01 June 2016 (has links)
This study examined the effects of drought on the City of San Bernardino Municipal Water Department’s (SBMWD’s) wastewater treatment plant (WWTP) wastewater flow rates and constituent concentrations. The study utilized data obtained from the SBMWD’s monthly discharge monitoring reports (DMRs), dating from 2007 to 2015. For each report the SBMWD Water Reclamation Plant (WRP) and Rapid Infiltration and Extraction (RIX) facility influent and effluent flow rates, along with concentrations of ammonia, biochemical oxygen demand (BOD), total suspended solids (TSS), total inorganic nitrogen (TIN), and total dissolved solids (TDS) were examined. Even though influent and effluent flow rates were examined for both WRP and RIX facilities, a majority of the flow-rate research concentrated on WRP influent flow rates because changes of influent flow rates cascade down the treatment process from WRP influent flow rates to RIX effluent flow rates. Impacts of the drought were analyzed by comparing drought statistics, for the Riverside-San Bernardino area, to influent flow rate trends and relevant constituent concentrations. Relevant constituent data were determined based on if they were discharged near their National Pollutant Discharge Elimination System (NPDES) permit limits. Pearson Correlation Analyses were used to assess any relationships between influent flow rates and relevant constituents. WRP influent flow rates and TIN concentrations were the only two parameters explored by this project that exhibited measurable changes related to the drought. WRP influent flow rates observed an inverse relationship with drought because persisting drought conditions led to decreased wastewater flow rates. TIN concentrations had a positive relationship with drought conditions based on the inverse correlation between influent flow rates, and the graphical relationship between drought conditions and TIN concentrations. The Pearson correlation coefficient for TIN concentrations and influent flow rates was -0.630 with a p-value less than 0.05, which is a strong negative relationship. Inconsistencies were observed during 2010 and 2011, which were non-drought periods. During non-drought periods it was expected that flow rates would be highest and constituent concentrations would be lowest. This was not the case because during 2010 and 2011 flow rates were lowest and TIN concentrations were highest, contradicting all other data. The drought-related justification for these abnormalities was that the implementation of the 20x2020 Water Conservation Plan, a California water management plan enacted in 2009, increased water conservation and reduced wastewater flow rates. However, there are many other factors that were not explored by this project that could have led to decreased wastewater flow rates, such as housing foreclosure rates peaking during 2010. Further studies are recommended.
218

EVALUATION OF A FILTRATION SORBENT FOR REMEDIATION OF ARSENIC IN GROUNDWATER

Do, Clement 01 June 2017 (has links)
A commercially available product, PURA PhosLock, was identified and evaluated for use as a sorbent to remove dissolved arsenic (As) from drinking water. Although marketed as a product to remove phosphate in aquaria, it is composed of iron oxide hydroxide (i.e., FeO(OH)), which is also known to adsorb dissolved As species from water. Arsenic was measured using standard methods and Graphite Furnace Atomic Absorption Spectroscopy. A first rough filtration test was performed to see if the PhosLock adsorbed As well. About 50 g of PhosLock was used to filter 10 L of tap water containing 100 ppb As. No detectable As was observed in the filtrate. A sorption study was then performed to determine the time required to reach equilibrium, which was attained after seven hours. A second set of sorption studies were performed using different As concentrations and the data was evaluated using the Langmuir adsorption model. The model predicted a maximum adsorption capacity of 457 to 636 mg/g. A final flowing water column breakthrough experiment was performed. Tap water spiked with 50 ppb was filtered through 0.5 grams of sorbent in a glass chromatography column. The results showed that seven liters of water were filtered before any As was detected. Over 10 L were filtered before the maximum contaminant level ( MCL) of 10 ppb was exceeded. The flow through study results showed that the PhosLock has an As adsorption capacity of 700 mg/g. This is consistent with the highest sorption capacity predicted by the Langmuir model. The results of this study show that PhosLock is a very effective and economical sorbent for the removal of As from drinking water.
219

Development of a Steady-State River Hydrodynamic and Temperature Model Based on CE-QUAL-W2

Xu, Wenwei 26 January 2014 (has links)
CE-QUAL-W2 is a 2-D hydrodynamic and water quality model that has been applied to reservoirs, lakes, river systems, and estuaries throughout the world. However, when this model is applied for shallow systems, this model requires a long calculation time to maintain numerical stability, compared to applications of reservoirs or deeper river systems. To solve this problem, a new hydrodynamic and temperature model was built based on the framework of CE-QUAL-W2 but that allows for steady-state hydrodynamic computations. By calculating the hydrodynamics at steady-state, the time step for stability is relaxed and simulations can proceed at much higher time steps. The rest of the model framework is still used for water quality state variables, in this case, temperature. The algorithm used for computing the water surface elevation is Manning's equation. This thesis study is one part of the Willamette Water 2100 project (Santelmann et al., 2012), which examines hydrological, ecological, and human factors affecting water scarcity in the Willamette River Basin. This study included three stages: (1) Convert six existing CE-QUAL-W2 V3.1 models into a newer version: CE-QUAL-W2 V3.7. (2) Develop the steady-state model code in FORTRAN. (3) Test the steady-state model on three river systems in the Willamette River Basin at Year 2001 and 2002. The result proved that the steady-state model could reduce the computing time by 90% for river applications, while predicting dynamic river temperature with high accuracy at a two-minute time scale. This new model will be employed to simulate the future of the Willamette River System at a decadal or centennial timescales, addressing river temperature concerns and fish habitat issues.
220

Groundwater-Surface Water Interactions near Mosier, Oregon

Jones, Cullen Brandon 01 August 2016 (has links)
The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that has received relatively little attention is the interaction between groundwater and surface waters at locations where interflow zones are intersected by the surface waters. The objective of my research is to investigate how CRBG interflow zone exposures in Mosier Creek may be controlling groundwater elevations in the area. The methods used include: (1) geochemical analysis of well cuttings and detailed geologic mapping along area streams to identify interflow zones of individual CRBG flows, (2) analysis of stream discharge data and groundwater elevation data to confirm exchange of groundwater and surface waters, and (3) collection and analyses of 31 water samples from area wells, streams, and springs, to determine if waters from individual CRBG aquifers can be hydrochemically identified and to further constrain understanding of surface and groundwater interactions. My study confirms that the general elevation of the Pomona Member and Basalt of Lolo interflow zone creek exposure is coincident with the elevation where a change in slope of the decline trend in 2004 is seen in Mosier area well hydrographs. Furthermore, the results of stream discharge data indicated a close connection between drawdown from groundwater pumping during irrigation season and groundwater- surface water interaction. At the time of drawdown in the upper-most CRBG aquifer (Pomona), the stream transitions from gaining to losing water into the groundwater system. Elemental chemistry data indicates the Frenchman Springs Sentinel Gap aquifer waters are the most evolved waters in this study. Stable isotopic data reinforced this determination as the Sentinel Gap waters are the lightest, or most negative, with regard to δD and δ18O. Sentinel Gap samples were more depleted than other aquifer samples by 4.38 to 6.89 0/100 for δD and 0.39 to 0.59 0/100 for δ18O. The results of the general chemistry and isotope data reveal a more evolved chemical signature in lower watershed groundwater versus a less evolved signature for waters from wells located higher up on the Columbia Hills anticline. This was interpreted to be the result of the major structural features in the area providing for a more regional pathway of recharge in lower watershed groundwaters, versus a more local source of recharge for upper watershed groundwaters. There was also a pronounced commingled signature in the elemental ratios of lower watershed aquifer waters. The suspected mechanism of recharge to lower watershed wells is through younger Cascadian deposits upslope from the local watershed. The findings of this study reveal the importance of a detailed understanding of CRBG stratigraphy and its relation to surface waters, especially for other areas within the Yakima Fold Belt or Oregon and Washington. Studies that do not consider the influence that individual CRBG flows can have on groundwater-surface water interactions, and the groundwater system as a whole, run the risk of improperly assessing the groundwater resource for a region.

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