Environmental management has increasingly become a participatory process. In recent times, emphasis has been placed on watershed-based solutions to remediate the problems of diffuse source pollution and to engage stakeholders in designing solutions. Water quality models are an integral part of this process; such models are often inaccessible to lay stakeholders. A review of the literature suggests that properly applied partnerships have several benefits that go beyond decision-making. Stakeholder education and enhancements to the eventual outcome from stakeholder insight and support are two such benefits. To aid engineers and scientists, who often do not interact directly with other stakeholders, several best practices were identified that may be applied to develop, manage, and evaluate stakeholder partnerships. Environmental Decision Support Systems (EDSSs) have been shown to be an effective way to promote stakeholder partnerships in environmental decision-making. Many current EDSSs were designed to be used by experts, thus limiting their effectiveness for stakeholder engagement. Often, these EDSSs, if designed for lay stakeholders, were not coupled with water quality models. To demonstrate that complex water quality models may be made accessible to stakeholders, without any significant changes to the modeling scheme, a web-based EDSS was developed for the Occoquan Reservoir, located in northern Virginia, U.S.A., and its tributary watershed. The developed EDSS may also be readily extended to other watersheds and their modeling programs. The current implementation of the EDSS enables users to modify land use and analyze simulated changes to water quality due to these modifications. A local-network server cluster, based on the Locally Distributed Simultaneous Model Execution (LDSME) framework, was also developed and served as a backend to the EDSS. The server cluster can support simultaneous execution of multiple water quality models or any other software on disparate computers. This system was employed to study pre-development and other land use modification scenarios in the Occoquan Watershed. The pre-development scenario offers an easy-to-understand and universally-applicable baseline for measuring waterbody and watershed restoration progress. It enabled computation of a measure called the "developed-excess," which is independent of local conditions and may be used for comparisons among various watershed sub-divisions or between watersheds. / Ph. D.

No contexto da disponibilidade hídrica comprometida pela poluição de mananciais da Região Metropolitana de São Paulo e da preocupação dos gestores quanto à inadequação desta água para o abastecimento público, este trabalho apresenta a modelagem matemática como uma ferramenta de auxílio na identificação das causas e minimização de impactos negativos sobre proliferação de algas no reservatório Jundiaí. O modelo CE-QUAL-W2, bidimensional na longitudinal e vertical, é aplicado para a representação da hidrodinâmica e da qualidade da água no reservatório, para posterior avaliação de oxigênio dissolvido e clorofila-a. A calibração e a validação do modelo foram realizadas a partir de dados de monitoramento de perfil e superfície no reservatório, permitindo a caracterização do regime de mistura polimítico e das concentrações de algas e oxigênio dissolvido, entre os anos de 2012 e 2017. Notou-se que as discrepâncias entre as concentrações do epilímnio e do hipolímnio não permanecem por longos períodos, devido à frequência de mistura e estratificação instável no reservatório estudado. Evidenciou-se a necessidade de se caracterizarem as populações de algas e cianobactérias presentes no reservatório, por serem as variáveis de maior influência nos índices de algas e oxigênio. Quanto aos fatores externos que interferem na proliferação de algas, destaca-se o aporte difuso de nutrientes diretamente afluente ao reservatório, sendo também relevantes a radiação solar de onda curta, a elevação de temperatura do ar, e nutrientes provenientes dos tributários e da transferência de água do canal de interligação entre os reservatórios Biritiba e Jundiaí. Alternativas para controle de blooms de algas, no caso em estudo, incluem o controle da utilização de fertilizantes e pesticidas, preservação da mata ciliar e a implantação de bacias de retenção ou de alagados (wetlands). / In the context of water availability compromised by the pollution of water resources in the Metropolitan Region of São Paulo and the concern of managers regarding its inadequacy for water supply, this work presents mathematical modeling as a tool for identifying the causes of and minimizing negative impacts on algal blooms in the Jundiaí Reservoir. CE-QUAL-W2, a two-dimensional longitudinal-vertical model, is applied for hydrodynamics and water quality representation of the reservoir, for further evaluation of dissolved oxygen and chlorophyll-a. Model calibration and validation were performed based on profile and surface monitoring data, allowing the characterization of the polymictic regime and the concentrations of algae and dissolved oxygen, between the years 2012 and 2017. It was noted that the discrepancies between the concentrations of epilimnium and hypolimnium do not remain for long periods, due to the frequency of mixing and unstable stratification in the reservoir. It was evidenced the need to characterize populations of algae and cyanobacteria present in the reservoir, since they are the variables that have the greatest influence on algal and oxygen indices. As for the external factors that interfere in algal proliferation, the diffuse contribution of nutrients directly to the reservoir needs special attention, being also relevant short-wave solar radiation, rise of air temperature, nutrients from the tributaries and transfer from interconnection channel between the Biritiba and Jundiaí reservoirs. Alternatives for control of algae blooms in the present case include control of the use of fertilizers and pesticides, preservation of riparian vegetation, retention basins and wetlands.

No contexto da disponibilidade hídrica comprometida pela poluição de mananciais da Região Metropolitana de São Paulo e da preocupação dos gestores quanto à inadequação desta água para o abastecimento público, este trabalho apresenta a modelagem matemática como uma ferramenta de auxílio na identificação das causas e minimização de impactos negativos sobre proliferação de algas no reservatório Jundiaí. O modelo CE-QUAL-W2, bidimensional na longitudinal e vertical, é aplicado para a representação da hidrodinâmica e da qualidade da água no reservatório, para posterior avaliação de oxigênio dissolvido e clorofila-a. A calibração e a validação do modelo foram realizadas a partir de dados de monitoramento de perfil e superfície no reservatório, permitindo a caracterização do regime de mistura polimítico e das concentrações de algas e oxigênio dissolvido, entre os anos de 2012 e 2017. Notou-se que as discrepâncias entre as concentrações do epilímnio e do hipolímnio não permanecem por longos períodos, devido à frequência de mistura e estratificação instável no reservatório estudado. Evidenciou-se a necessidade de se caracterizarem as populações de algas e cianobactérias presentes no reservatório, por serem as variáveis de maior influência nos índices de algas e oxigênio. Quanto aos fatores externos que interferem na proliferação de algas, destaca-se o aporte difuso de nutrientes diretamente afluente ao reservatório, sendo também relevantes a radiação solar de onda curta, a elevação de temperatura do ar, e nutrientes provenientes dos tributários e da transferência de água do canal de interligação entre os reservatórios Biritiba e Jundiaí. Alternativas para controle de blooms de algas, no caso em estudo, incluem o controle da utilização de fertilizantes e pesticidas, preservação da mata ciliar e a implantação de bacias de retenção ou de alagados (wetlands). / In the context of water availability compromised by the pollution of water resources in the Metropolitan Region of São Paulo and the concern of managers regarding its inadequacy for water supply, this work presents mathematical modeling as a tool for identifying the causes of and minimizing negative impacts on algal blooms in the Jundiaí Reservoir. CE-QUAL-W2, a two-dimensional longitudinal-vertical model, is applied for hydrodynamics and water quality representation of the reservoir, for further evaluation of dissolved oxygen and chlorophyll-a. Model calibration and validation were performed based on profile and surface monitoring data, allowing the characterization of the polymictic regime and the concentrations of algae and dissolved oxygen, between the years 2012 and 2017. It was noted that the discrepancies between the concentrations of epilimnium and hypolimnium do not remain for long periods, due to the frequency of mixing and unstable stratification in the reservoir. It was evidenced the need to characterize populations of algae and cyanobacteria present in the reservoir, since they are the variables that have the greatest influence on algal and oxygen indices. As for the external factors that interfere in algal proliferation, the diffuse contribution of nutrients directly to the reservoir needs special attention, being also relevant short-wave solar radiation, rise of air temperature, nutrients from the tributaries and transfer from interconnection channel between the Biritiba and Jundiaí reservoirs. Alternatives for control of algae blooms in the present case include control of the use of fertilizers and pesticides, preservation of riparian vegetation, retention basins and wetlands.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.

The Occoquan Watershed is a 1515 square kilometer basin located in northern Virginia and contains two principal waterbodies: the Occoquan Reservoir and Lake Manassas. Both waterbodies are principal drinking water supplies for local residents and experience eutrophication and summer algae growth. They are continuously threatened by new development from the rapid expansion of the greater Washington D.C. region. The Occoquan model, consisting of six HSPF and two CE-QUAL-W2 submodels linked in a complex way, has been developed and applied to simulate hydrology and water quality activities in the two major reservoirs and the associated drainage areas. The studied water quality constituents include temperature, dissolved oxygen, ammonium nitrogen, oxidized nitrogen, orthophosphate phosphorus, and algae. The calibration of the linked model is for the years 1993-95, with a validation period of 1996-97. The results show that a successful calibration can be achieved using the linked approach, with moderate additional effort. The spatial and temporal distribution of hydrology processes, nutrient detachment and transport, stream temperature and dissolved oxygen were well reproduced by HSPF submodels. By using the outputs generated by HSPF submodels, the CE-QUAL-W2 submodels adequately captured the water budgets, hydrodynamics, temperature, temporal and spatial distribution of dissolved oxygen, ammonium nitrogen, oxidized nitrogen, orthophosphate phosphorus, and algae in Lake Manassas and Occoquan Reservoir. This demonstrates the validity of linking two types of state of the art water quality models: the watershed model HSPF and the reservoir model CE-QUAL-W2. One of the advantages of the linked model approach is to develop a direct cause and effect relationship between upstream activities and downstream water quality. Therefore, scenarios of various land use proposals, BMP implementation, and point source management can be incorporated into HSPF applications, so that the CE-QUAL-W2 submodels can use the boundary conditions corresponding with these scenarios to predict the water quality variations in the receiving waterbodies. In this research, two land use scenarios were developed. One represented the background condition assuming all the land covered by forest and the other represented the environmental stress posed by future commercial and residential expansion. The results confirm the increases of external nutrient loads due to urbanization and other human activities, which eventually lead to nutrient enrichment and enhanced algae growth in the receiving waterbodies. The increases of external nutrient loads depend on land use patterns and are not evenly spread across the watershed. The future development in the non urban areas will greatly increase the external nutrient production and BMPs should be implemented to reduce the potential environmental degradation. For the existing urban areas, the model results suggest a potential threshold of nutrient production despite future land development. The model results also demonstrate the catchment function of Lake Manassas in reducing nutrient transport downstream. / Ph. D.

<p>Estuaries interfacing with the land, atmosphere and open oceans can be influenced in a variety of ways by anthropogenic activities. Centuries of overexploitation, habitat transformation, and pollution have degraded estuarine ecological health. Key concerns of public and environmental managers of estuaries include water quality, particularly the enrichment of nutrients, increased chlorophyll a concentrations, increased hypoxia/anoxia, and increased Harmful Algal Blooms (HABs). One reason for the increased nitrogen loading over the past two decades is the proliferation of concentrated animal feeding operations (CAFOs) in coastal areas. This dissertation documents a study of estuarine eutrophication modeling, including modeling of major source of nitrogen in the watershed, the use of the Bayesian Networks (BNs) for modeling eutrophication dynamics in an estuary, a documentation of potential problems of using BNs, and a continuous BN model for addressing these problems.</p><p>Environmental models have emerged as great tools to transform data into useful information for managers and policy makers. Environmental models contain uncertainty due to natural ecosystems variability, current knowledge of environmental processes, modeling structure, computational restrictions, and problems with data/observations due to measurement error or missingness. Many methodologies capable of quantifying uncertainty have been developed in the scientic literature. Examples of such methods are BNs, which utilize conditional probability tables to describe the relationships among variables. This doctoral dissertation demonstrates how BNs, as probabilistic models, can be used to model eutrophication in estuarine ecosystems and to explore the effects of plausible future climatic and nutrient pollution management scenarios on water quality indicators. The results show interaction among various predictors and their impact on ecosystem health. The synergistic eftects between nutrient concentrations and climate variability caution future management actions.</p><p>BNs have several distinct strengths such as the ability to update knowledge based on Bayes' theorem, modularity, accommodation of various knowledge sources and data types, suitability to both data-rich and data-poor systems, and incorporation of uncertainty. Further, BNs' graphical representation facilitates communicating models and results with environmental managers and decision-makers. However, BNs have certain drawbacks as well. For example, they can only handle continuous variables under severe restrictions (1- Each continuous variable be assigned a (linear) conditional Normal distribution; 2- No discrete variable have continuous parents). The solution, thus far, to address this constraint has been discretizing variables. I designed an experiment to evaluate and compare the impact of common discretization methods on BNs. The results indicate that the choice of discretization method severely impacts the model results; however, I was unable to provide any criteria to select an optimal discretization method.</p><p>Finally, I propose a continuous variable Bayesian Network methodology and demonstrate its application for water quality modeling in estuarine ecosystems. The proposed method retains advantageous characteristics of BNs, while it avoids the drawbacks of discretization by specifying the relationships among the nodes using statistical and conditional probability models. The Bayesian nature of the proposed model enables prompt investigation of observed patterns, as new conditions unfold. The network structure presents the underlying ecological ecosystem processes and provides a basis for science communication. I demonstrate model development and temporal updating using the New River Estuary, NC data set and spatial updating using the Neuse River Estuary, NC data set.</p> / Dissertation

The main goal of the thesis is to create an accurate model of the current state of water quality modelling in the river basin. The basin of the Olšava River, as found in the bachelor thesis "Analysis of Water Quality in the Basin", is polluted with large concentrations of total phosphorus PTot. The master thesis analyses sources of nutrients in the basin that is mainly listed in the vulnerable areas indentified under the Nitrates Directive 91/676/EEC, on the protection of waters against pollution caused by nitrates from agricultural sources. For the water resources management and environmental policy is crucial to recognize distribution of pollution sources throughout main categories. The thesis is concerned with the seasonal variability of the average mass concentrations along the river channel. Broadly used mathematical modelling software of water quality is discussed in the sense of reliability, availability and user interface. Last but not least is a suggestion of two improvements of the water quality based on the MIKE Basin modelling software. The main aim of these proposals is to be realistic in the economical and environmental sense. Proposals consider both in point and non-point sources. Key words: Mathematical modelling, MIKE Basin, Water Quality, Water Quality models, Hydrology, Olšava

Orientador: Edevar Luvizotto Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-09T19:18:58Z (GMT). No. of bitstreams: 1 Trimboli_MarceloJose_M.pdf: 5392045 bytes, checksum: cc7d8b290241329ec9e101fc336f718c (MD5) Previous issue date: 2006 / Resumo: Neste trabalho são estudadas e avaliadas as etapas que visam a aplicação de modelagem matemática para obtenção de parâmetros de qualidade como a concentração de cloro livre residual em sistemas de abastecimento de água. Como estudo de caso e avaliação da proposição fui empregado o setor de abastecimento de Vila Liberdade na Cidade de Jundiaí-SP. Os resultados foram comparados com medições exaustivas de campo / Abstract: This work were studied and evaluated the stages that look for the use of the mathematics modeling to get parameters of quality like residual free chlorine concentration in network pipes . How case study and valuation of the proposition it was used the water supply sector of Vila Liberdade in the town of Jundiai - estate of São Paulo, BraziL The results were compared with exhaustive field measures / Mestrado / Recursos Hidricos / Mestre em Engenharia Civil

A qualidade da água do século XXI é um dos principais problemas da humanidade em decorrência de atividades de mineração, lançamentos de esgotos domésticos e industriais sem tratamento, utilização de agrotóxicos e pesticidas, retirada da vegetação ripária e depósito de lixo. A gestão dos recursos hídricos engloba, entre outras ações, caracterização ambiental, avaliação dos impactos das atividades instaladas na área de influência, investigação da capacidade de assimilação do corpo receptor, monitoramento ambiental e retroalimentação do processo de gestão como um todo. A proposta deste trabalho foi estudar a dinâmica dos rios Jacupiranguinha, município de Cajati - SP e Pariquera-Açu, município de Pariquera-Açu - SP (Bacia do Rio Ribeira de Iguape) nas diferentes fases do ciclo hidrológico, e propor cenários com vistas à sustentabilidade dos recursos hídricos do Baixo Ribeira de Iguape. Foram medidas variáveis físicas e químicas da água e do sedimento, além da quantidade de coliformes fecais e as estruturas da comunidade bentônica dos rios, além de variáveis climatológicas e hidrológicas. O modelo QUAL2K foi utilizado como ferramenta para diferentes simulações de cenários para a sub-bacia do rio Jacupiranguinha. Os resultados mostraram que os rios sofrem os impactos decorrentes da urbanização tanto com relação ao escoamento superficial urbano quanto com a entrada de efluentes clandestinos e de estações de tratamento. Este fato foi percebido pela alteração da qualidade das águas em relação à concentração de nutrientes e coliformes totais e fecais. Os sedimentos foram classificados como mineral e a constituição granulométrica pode ter contribuído para a estrutura da comunidade de macroinvertebrados que foi maior no rio Pariquera-Açu, pois este possui sedimento mais heterogêneo. A classe Insecta foi representada por maior quantidade de taxa e a família Chironomidae foi a que apresentou maior densidade absoluta de organismos. Estes resultados podem indicar comprometimento da saúde das sub-bacias. Pôde-se constatar através das simulações que a sub-bacia do rio Jacupiranguinha necessita de algumas intervenções em saneamento para a melhoria da qualidade de suas águas e que, para algumas variáveis, o estágio de poluição supera os limites de autodepuração do rio. Neste caso, medidas de conservação já não seriam suficientes, necessitando da implantação de um processo de recuperação da qualidade destas águas. / The twenty-first century water quality is one of the main problems of mankind as a result of mining activities, release of untreated industrial and domestic sewage, use of agrochemicals and pesticides, removal of riparian vegetation and garbage dump. Water resources management includes environmental characterization, impact assessment of activities located in influence area, to investigate the receiving body assimilative capacity, environmental monitoring and feedback management process as a whole. The purpose of this work was to study the dynamics of rivers Jacupiranguinha, Cajati city and Pariquera-Açu, Pariquera-Açu city - Brazil (Ribeira de Iguape River Basin) in different phases of the hydrological cycle, and propose scenarios to water resources sustainability of the Ribeira de Iguape basin. Water and sediment physical and chemical variables, fecal coliforms and benthic community structure of rivers were measured, besides the weather and hydrological conditions. QUAL2K model was used as a tool for simulations of different scenarios for the sub-basin of Jacupiranguinha river. The results showed that the rivers are suffering the impacts of urbanization both in relation to urban runoff as the discharge of illegal domestic effluents and those from treatment stations. This fact was noticed by water quality changes on nutrient concentrations and total and fecal coliforms. The sediments were classified as mineral formation and particle size may have contributed to the benthic community structure which was higher in Pariquera-Açu river, because of its sediment heterogeneity. Insecta was dominant and Chironomidae showed the largest absolute density of organisms. These results may indicate impairment of health of sub-basins. It could be observed through simulations that Jacupiranguinha river needs some assistance in sanitation to improve the quality of its waters and the stage of pollution exceeds the limits of river self-purification. In this case, conservation measures would no longer be sufficient, necessitating the deployment of a recovery process of the quality of these waters.

A qualidade da água do século XXI é um dos principais problemas da humanidade em decorrência de atividades de mineração, lançamentos de esgotos domésticos e industriais sem tratamento, utilização de agrotóxicos e pesticidas, retirada da vegetação ripária e depósito de lixo. A gestão dos recursos hídricos engloba, entre outras ações, caracterização ambiental, avaliação dos impactos das atividades instaladas na área de influência, investigação da capacidade de assimilação do corpo receptor, monitoramento ambiental e retroalimentação do processo de gestão como um todo. A proposta deste trabalho foi estudar a dinâmica dos rios Jacupiranguinha, município de Cajati - SP e Pariquera-Açu, município de Pariquera-Açu - SP (Bacia do Rio Ribeira de Iguape) nas diferentes fases do ciclo hidrológico, e propor cenários com vistas à sustentabilidade dos recursos hídricos do Baixo Ribeira de Iguape. Foram medidas variáveis físicas e químicas da água e do sedimento, além da quantidade de coliformes fecais e as estruturas da comunidade bentônica dos rios, além de variáveis climatológicas e hidrológicas. O modelo QUAL2K foi utilizado como ferramenta para diferentes simulações de cenários para a sub-bacia do rio Jacupiranguinha. Os resultados mostraram que os rios sofrem os impactos decorrentes da urbanização tanto com relação ao escoamento superficial urbano quanto com a entrada de efluentes clandestinos e de estações de tratamento. Este fato foi percebido pela alteração da qualidade das águas em relação à concentração de nutrientes e coliformes totais e fecais. Os sedimentos foram classificados como mineral e a constituição granulométrica pode ter contribuído para a estrutura da comunidade de macroinvertebrados que foi maior no rio Pariquera-Açu, pois este possui sedimento mais heterogêneo. A classe Insecta foi representada por maior quantidade de taxa e a família Chironomidae foi a que apresentou maior densidade absoluta de organismos. Estes resultados podem indicar comprometimento da saúde das sub-bacias. Pôde-se constatar através das simulações que a sub-bacia do rio Jacupiranguinha necessita de algumas intervenções em saneamento para a melhoria da qualidade de suas águas e que, para algumas variáveis, o estágio de poluição supera os limites de autodepuração do rio. Neste caso, medidas de conservação já não seriam suficientes, necessitando da implantação de um processo de recuperação da qualidade destas águas. / The twenty-first century water quality is one of the main problems of mankind as a result of mining activities, release of untreated industrial and domestic sewage, use of agrochemicals and pesticides, removal of riparian vegetation and garbage dump. Water resources management includes environmental characterization, impact assessment of activities located in influence area, to investigate the receiving body assimilative capacity, environmental monitoring and feedback management process as a whole. The purpose of this work was to study the dynamics of rivers Jacupiranguinha, Cajati city and Pariquera-Açu, Pariquera-Açu city - Brazil (Ribeira de Iguape River Basin) in different phases of the hydrological cycle, and propose scenarios to water resources sustainability of the Ribeira de Iguape basin. Water and sediment physical and chemical variables, fecal coliforms and benthic community structure of rivers were measured, besides the weather and hydrological conditions. QUAL2K model was used as a tool for simulations of different scenarios for the sub-basin of Jacupiranguinha river. The results showed that the rivers are suffering the impacts of urbanization both in relation to urban runoff as the discharge of illegal domestic effluents and those from treatment stations. This fact was noticed by water quality changes on nutrient concentrations and total and fecal coliforms. The sediments were classified as mineral formation and particle size may have contributed to the benthic community structure which was higher in Pariquera-Açu river, because of its sediment heterogeneity. Insecta was dominant and Chironomidae showed the largest absolute density of organisms. These results may indicate impairment of health of sub-basins. It could be observed through simulations that Jacupiranguinha river needs some assistance in sanitation to improve the quality of its waters and the stage of pollution exceeds the limits of river self-purification. In this case, conservation measures would no longer be sufficient, necessitating the deployment of a recovery process of the quality of these waters.