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1
Yeates, Peter Stafford. "Deep mixing in stratified lakes and reservoirs." University of Western Australia. Centre for Water Research, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0046.
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The onset of summer stratification in temperate lakes and reservoirs forces a decoupling of the hypolimnion from the epilimnion that is sustained by strong density gradients in the metalimnion. These strong gradients act as a barrier to the vertical transport of mass and scalars leading to bottom anoxia and subsequent nutrient release from the sediments. The stratification is intermittently overcome by turbulent mixing events that redistribute mass, heat, dissolved parameters and particulates in the vertical. The redistribution of ecological parameters then exerts some control over the ecological response of the lake. This dissertation is focused on the physics of deep vertical mixing that occurs beneath the well-mixed surface layer in stratified lakes and reservoirs. The overall aim is to improve the ability of numerical models to reproduce deep vertical mixing, thus providing better tools for water quality prediction and management. In the first part of this research the framework of a one-dimensional mixed-layer hydrodynamic model was used to construct a pseudo two-dimensional model that computes vertical fluxes generated by deep mixing processes. The parameterisations developed for the model were based on the relationship found between lake-wide vertical buoyancy flux and the first-order internal wave response of the lake to surface wind forcing. The ability of the model to reproduce the observed thermal structure in a range of lakes and reservoirs was greatly improved by incorporating an explicit turbulent benthic boundary layer routine. Although laterally-integrated models reproduce the net effect of turbulent mixing in a vertical sense, they fail to resolve the transient distribution of turbulent mixing events triggered by local flow properties defined at far smaller scales. Importantly, the distribution of events may promote tertiary motions and ecological niches. In the second part of the study a large body of microstructure data collected in Lake Kinneret, Israel, was used to show that the nature of turbulent mixing events varied considerably between the epilimnion, metalimnion, hypolimnion and benthic boundary layer, yet the turbulent scales of the events and the buoyancy flux they produced collapsed into functions of the local gradient Richardson number. It was found that the most intense events in the metalimnion were triggered by high-frequency waves generated near the surface that grew and imparted a strain on the metalimnion density field, which led to secondary instabilities with low gradient Richardson numbers. The microstructure observations suggest that the local gradient Richardson number could be used to parameterise vertical mixing in coarse-grid numerical models of lakes and reservoirs. However, any effort to incorporate such parameterisations becomes meaningless without measures to reduce numerical diffusion, which often dominates over parameterised physical mixing. As a third part of the research, an explicit filtering tool was developed to negate numerical diffusion in a threedimensional hydrodynamic model. The adaptive filter ensured that temperature gradients in the metalimnion remained within bounds of the measured values and so the computation preserved the spectrum of internal wave motions that trigger diapycnal mixing events in the deeper reaches of a lake. The results showed that the ratio of physical to numerical diffusion is dictated by the character of the dominant internal wave motions.
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Gipey, Collins D. "Manganese analysis and speciation in freshwater lakes and reservoirs /." [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16202.pdf.
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Koçyigit, Müsteyde Baduna. "Numerical modelling of wind-induced circulation in lakes and reservoirs." Thesis, Cardiff University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412516.
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Bierlein, Kevin Andrew. "Predicting induced sediment oxygen flux in oxygenated lakes and reservoirs." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/73502.
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Bubble plume oxygenation systems are commonly used to mitigate anoxia and its deleterious effects on water quality in thermally stratified lakes and reservoirs. Following installation, increases in sediment oxygen flux (JO2) are typically observed during oxygenation and are positively correlated with the bubble plume gas flow rate. Studies show that JO2 is controlled by the thickness of the diffusive boundary layer (DBL) at the sediment-water interface (SWI), which is in turn controlled by turbulence. As a result, JO2 can be quite spatially and temporally variable.
Accurately predicting oxygenation-induced JO2 is vitally important for ensuring successful oxygenation system design and operation. Yet despite the current understanding of physical and chemical controls on JO2, methods for predicting oxygenation-induced JO2 are still based on empirical correlations and factors of safety. As hypolimnetic oxygenation becomes more widely used as a lake management tool for improving and maintaining water quality, there is a need to move from the current empirically based approach to a mechanistic approach and improve the ability to predict induced JO2. This work details field campaigns to investigate and identify appropriate models of oxygen supply to the SWI and oxygen demand exerted from the sediment, with the intent to use these models to predict oxygenation-induced JO2.
Oxygen microprofiles across the SWI and near-sediment velocity measurements were collected in situ during three field campaigns on two oxygenated lakes, providing simultaneous measurements of JO2 and turbulence. Field observations show that oxygenation can increase JO2 by increasing bulk hypolimnetic oxygen concentrations, which increases the concentration gradient across the SWI. Oxygenation can also enhance turbulence, which decreases the DBL thickness and increases JO2. Existing models of interfacial flux were compared to field measurements to determine which model best predicted the observed JO2. Models based on the Batchelor scale, friction velocity, and film-renewal theory all agree reasonably well with field observations in both lakes. Additionally, the oxygen microprofiles were used to fit a transient model of oxygen kinetics in lake sediment and determine the appropriate kinetic model. Oxygen microprofiles in both lakes can be described using zero-order kinetics, rather than first-order kinetics.
The interfacial flux and sediment kinetic models are incorporated into a coupled bubble plume and 3-D hydrodynamic lake model, allowing for spatial and temporal variation in simulated JO2. This comprehensive model was calibrated and validated to field data from two separate field campaigns on Carvin's Cove Reservoir, Virginia. Simulated temperature profiles agreed quite well with field observations, while simulated oxygen profiles differed from observed profiles, particularly in the bottom 1 m of the water column. The model overestimates oxygen concentrations near the sediment, which results in higher simulated JO2 than was observed during the field campaigns. These discrepancies are attributed to oxygen-consuming chemical processes, such as oxidation of soluble metals, which are not accounted for in the hydrodynamic model. Despite this, the model is still able to capture the impact of bubble plume operation on JO2, as simulated JO2 is higher when the diffusers are operating. With some additional improvements to the water quality modeling aspects of the model, as well as further calibration and validation, the model should be able to reproduce observed JO2 provided oxygen concentrations near the SWI are accurately reproduced as well. The current work is an attempt to push toward a comprehensive lake oxygenation model. A comprehensive model such as this should improve the ability to predict oxygenation-induced JO2 and lead to improvements in the design and operation of hypolimnetic oxygenation systems.Ph. D.
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Littlejohn, Carla Louise, and n/a. "Influence of Artificial Destratification on Limnological Processes in Lake Samsonvale (North Pine Dam), Queensland, Australia." Griffith University. Australian School of Environmental Studies, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050211.133123.
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Artificial destratification equipment was installed in Lake Samsonvale in October 1995 to reduce the biomass of potentially toxic cyanobacteria in the reservoir. This study was undertaken to investigate the effects of the destratifier on the limnological processes occurring in the lake and to determine if operation of the destratifier has been effective at reducing the summer populations of Cylindrospermopsis raciborskii and Microcystis aeruginosa. The study showed that artificial destratification of Lake Samsonvale has been successful at reducing the surface to bottom thermal gradient and increasing dissolved oxygen concentrations at depth. While the destratifier has not resulted in the lake becoming completely 'mixed' during summer, it has weakened resistance to mixing from meteorological events, which has led to a reduction in mean concentrations of total and dissolved phosphorus during summer. Although not conclusive, it is likely that the influence of the destratifier is restricted to a narrow radial distance around the bubbleplumes during periods of strong stability, so internal loading may continue to provide a substantial source of nutrients for cyanobacterial growth, particularly in regions of the lake less influenced by the destratifier. The results for cyanobacteria are less encouraging. Despite the reduction in concentrations of dissolved phosphorus, the destratifier has not been effective at reducing summer populations of C. raciborskii and M. aeruginosa. On the contrary, there is evidence to suggest that populations have actually increased which could have serious operational consequences for the lake by mixing the previously buoyant cyanobacteria to the level of the water off-take. The growth season for C. raciborskii has been extended by up to 3 months and population onset now occurs during spring. This increase in spring populations could be a result of significantly greater baseline populations during winter, or the earlier germination of akinetes as a result of increased sediment temperatures. The seasonal successional relationship between C. raciborskii and M. aeruginosa appears to have shifted from one of alternating dominance between the two species to one of co-existence under conditions of intermediate disturbance. It was concluded that although the continued operation of the destratifier may prove useful to minimise water treatment costs through reducing internal loading of dissolved constituents, it has not been successful in achieving its original objective of controlling cyanobacterial populations in the lake.
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Doubek, Jonathan Patrick. "The Effects of Hypoxia on Zooplankton Communities in Lakes and Reservoirs." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/83574.
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Global change is altering the community composition, variability, and behavior of organisms in a diverse suite of ecosystems. Because of climate change and eutrophication, freshwater lakes and reservoirs are experiencing an increase in low dissolved oxygen concentrations (hypoxia) in their bottom waters (hypolimnion), which can disrupt ecological communities. Zooplankton, important aquatic organisms for regulating water quality and food webs, are one group of organisms affected by hypoxia since zooplankton need oxygen to respire.
My research shows that hypoxia may disrupt zooplankton behavior and increase the variability of zooplankton communities. Zooplankton ubiquitously exhibit diel vertical migration, where the majority of the population resides in the hypolimnion during the daytime to escape predation from fish and damage from ultraviolet radiation. At night, many zooplankton ascend to the surface waters to feed on phytoplankton, when there is decreased risk of predation and radiation.
My results from intensive 24-hour sampling campaigns suggest that hypolimnetic hypoxia may alter zooplankton migration, biomass, and behavior, which may in turn exacerbate water quality degradation due to the critical role zooplankton play in freshwater ecosystems. In addition, field surveys in four reservoirs over three years revealed that hypoxia may increase the variability of zooplankton communities compared to oxic conditions. Consequently, as lakes and reservoirs experience increased extent and duration of hypoxia in the future, it is critical to understand how more variable zooplankton communities alter freshwater ecosystem functioning.Ph. D.
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Morillo, Sebastian. "Engineering solutions to water quality problems in lakes." University of Western Australia. Centre for Water Research, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0153.
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Lake restoration and management strategies focus on reducing the negative impacts of enriched or polluted inflows. These strategies become of paramount importance when lakes are used for recreational and/or drinking water purposes. Long term control of eutrophication and turbidity problems associated with large inflow loads is usually oriented to catchment management. Although it has been suggested that this is the correct long term approach, public concerns usually require a short term solution. In addition, due to political and economic costs related to changes in catchment management, in-lake restoration technologies have been emerging as a viable pretreatment option, complementary to water treatment plants, both reducing the operational costs of the water treatment plant and ameliorating the water residing in the lakes. This research investigates the effects of two in-lake technologies on the dynamics of inflowing rivers, where basin shape plays a significant role. The three lakes in this study suffer from eutrophication combined with a distinctive water quality problem: from turbidity in Silvan Reservoir (Australia), to heavy metal loads in Coeur d'Alene Lake (USA) and industrial wastes in Lake Como (Italy). Firstly, the influence of basin morphology, wind speed, and wind direction on the fate and transport of two rivers flowing into the L-shaped Coeur d'Alene Lake was examined, and it was shown that transport and mixing patterns in a lake can be greatly influenced by the shape of the lake, leading to important consequences for the plankton ecology in the lake. Secondly, in Silvan Reservoir we investigated the potential to modify the basin shape using vertical barriers, increasing the retention time and hence the barrier capacity to microbial pollution. A final in-lake technology was tested for Lake Como, using a downward pointing impeller to remove polluted water from the coastal margin. Lessons from these three examples indicate that there is significant potential for in-lake remediation at relatively low cost, over relatively short timescales.
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Weisbrod, Barbara [Verfasser]. "Dynamics of toxic cyanobacteria in lakes and artificial water reservoirs / Barbara Weisbrod." Konstanz : KOPS Universität Konstanz, 2021. http://d-nb.info/1228271925/34.
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Wilson, Helen M. "An evaluation of alternative management strategies for shallow eutrophicated lakes and reservoirs." Thesis, University of Plymouth, 1995. http://hdl.handle.net/10026.1/1870.
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External phosphorus loadings on a range of freshwater Sites of Special Scientific Interest (SSSIs) thought to be affected by eutrophication were predicted utilising export coefficients. The effect of such loadings on lake trophic status was evaluated using the Vollenweider-OECD eutrophication model. Estimates of the relative contribution of phosphorus from various sources enabled the selection of possible reduction strategies on a site specific basis. The effect of reduction strategies on trophic status was predicted with the aid of the model. It was established that diffuse agricultural losses of phosphorus are the most common source of enrichment. However, consented discharges of sewage efHuent appear to affect a significant number of sites. Phosphorus in urban runoff is a notable source for lakes situated in less rural areas. Agricultural point sources significantly influence a small number of lakes. A critique of the methodology concluded that the use of separate export coefficients for organic and inorganic sources may be useful for identifying appropriate management strategies, but that the scientific basis for such an approach is dubious. In addition, the employment of agricultural returns for data on livestock levels may introduce an unacceptable degree of error into the calculations. The Vollenweider-OECD model appears to predict the trophic status of the lakes under assessment reasonably well, but there is a need for a reliable method of ascertaining loading reduction objectives. A review of current legislation and policy applicable to the alleviation of eutrophication of freshwater SSSIs encompassed laws relating to nature conservation, to water quality, and to agricultural extensiflcation. It confirmed that legislation which directly addresses the problem is nonexistent, but that certain laws may be applied in a piecemeal manner. In general, the form of nature conservation protection adopted in this country is not designed to prevent deterioration of water quality. An aspect of eutrophication control which may prove to be the most problematical in legislative teniis is the regulation of diffuse agricultural sources of phosphorus. Proposals for changes in law and policy on this issue included the establishment of a catchment-wide scheme, specifically designed to reduce diffuse agricultural lossesof phosphorus, and targeted at eutrophicated SSSIs.
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Garaway, Caroline Jane. "Small waterbody fisheries and the potential for community-led enhancement : case studies in Lao PDR." Thesis, Imperial College London, 1999. http://hdl.handle.net/10044/1/12552.
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Based on case studies in Lao PDR, this research investigates the importance of small waterbody fisheries to rural households, the impact of enhancement initiatives on resources and resource users, and the opportunities and constraints of communityled enhancement. Detailed biological, socio-economic, and institutional data on small water body fisheries were collected and analysed in an integrated framework. Small waterbody fisheries contributed substantially to rural livelihoods, with average household catches of 66 kg/year, equivalent in value to approximately half the household rice production (the major crop grown in the region). Poorer households caught and sold more fish than other socio-economic groups. Active management of small waterbody fisheries by stocking and the regulation of fishing had significant impacts on fish stocks, yields, and the type, magnitude and distribution of benefits to villagers. Stocked fisheries managed by and for the village showed higher standing stocks and returns to fishing effort, and thus generated substantial efficiency benefits even though yields were not significantly higher than in unmanaged fisheries. Benefits were in the form of income to the community, partially passed on to households, (equally between socio-economic groups), through reduced financial contributions to the village. Institutional analysis suggests that locally adapted rules, ownership rights, low cost monitoring and enforcement, and information about benefits are key factors in promoting and sustaining community enhancement efforts, as well as the presence of individuals with substantial leadership skills. Results suggest that communities can and do successfully set up and maintain enhancement initiatives and that enhancement of small water body fisheries can generate substantial benefits. However these will only be sustained if it corresponds to villager's objectives and coincides with conducive institutional arrangements and, crucially, an enabling external policy environment. To achieve the full potential of enhancements, research should be aimed at furthering villager's understanding of the status and potential of their resource in terms of these objectives.
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Thompson, Lisa C. "The influence of hydraulic retention time on planktonic biomass in lakes and reservoirs /." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56754.
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Hydraulic retention time (HRT) might contribute to the substantial variation in phosphorus-chlorphyll and chlorophyll-zooplankton models because rapid flushing might depress plankton development. However, for a world-wide data set. HRT was not correlated with chlorophyll. Total phosphorus had no effect on chlorphyll when hypereutrophic sites were considered separately, but chlorophyll was negatively related to HRT. Short term HRT, averaged over periods up to one month, was not correlated with chlorophyll, or zooplankton biomass, in seven impoundments on the St. Lawrence and Ottawa Rivers. The size distribution of algae was not affected by HRT. The proportion of rotifer to total zooplankton biomass was positively related to HRT, but this trend disappeared when nauplius biomass was removed from the total. These results indicate that rapid flushing does not necessarily reduce planktonic biomass and that short term HRT is not useful for the prediction and management of planktonic biomass in these systems.
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Mehling, Molly Gail. "DEVELOPMENT AND APPLICATION OF A GEOSPATIAL DATABASE OF SIERRA NEVADA LAKES AND RESERVOIRS." Miami University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=miami1142529953.
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Olding, Daniel D. "Phytoplankton community composition in relation to environmental conditions in urban lakes, ponds and reservoirs." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0003/MQ40701.pdf.
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Allen, Jason D. "Correlating phytoplankton assemblages with water quality in Illinois lakes and reservoirs : validating models based on historical data /." View online, 2008. http://repository.eiu.edu/theses/docs/32211131464742.pdf.
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Gorrie, Jason Robert. "An Examination Of Water Quality Impacts On Lake Manassas." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/32815.
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Lake Manassas is a man-made impoundment in the Northern Virginia suburbs of Washington, D.C. The lake currently supplies drinking water at an average rate of 10.5 million gallons per day to the City of Manassas, Virginia. The lake discharges, via the Broad Run, a tributary of the Occoquan Reservoir. The Occoquan Reservoir supplies potable water to over 750,000 people in the Northern Virginia area.
This thesis presents the results of a limnological analysis of Lake Manassas. The techniques used are established limnological techniques to arrive at a profile which can be compared to accepted scales of ranking.
One conclusion from the analysis is that Lake Manassas is eutrophic, which means that the production of biomass in the lake is at a higher than desired rate. The result of this eutrophic condition is that the water quality of the lake will decline rather rapidly. Another conclusion is that Broad Run is the major supplier of nutrients into Lake Manassas, but that conditions are also affected by a point source discharge from a sewage treatment plant. These conclusions are consistent with previous studies done on Lake Manassas.
In summary, Lake Manassas is an important water resource in the Northern Virginia area, and it is important to continue to closely monitor and manage runoff practices in the watershed to ensure the lake does not degrade to unacceptable conditions.Master of Science
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Crile, Patrick. "A Limnological Analysis of Lake Manassas, with an Updated Baseline Through 2010." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/19337.
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Lake Manassas is an approximate 706 acre man-made lake located in greater Prince William County near the town of Gainesville, Virginia. The lake was created in 1968 on Broad Run to serve as the primary water supply for the City of Manassas and its residents. The Lake Manassas watershed lies within the greater Occoquan River watershed which drains into the Potomac River and Chesapeake Bay. Water within Lake Manassas and its tributaries has been monitored since 1971 and this thesis presents a comprehensive limnological analysis of the Lake with an analysis of water quality impacts over time. Lake Manassas remains an enriched or eutrophic system, meaning the levels of nutrients and biomass production in lake waters is above desired standards. Nutrient loading occurs via a stream network with the largest contributor being Broad Run which is consistent with previous water quality studies.
The lake serves as the sole water source for nearly 40,000 residents and businesses and ensuring clean and safe water is of significant importance. Close monitoring in conjunction with the implementation of appropriate management practices within the watershed are necessary to prevent water quality from becoming significantly degraded.
Master of Science
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John, V. Chandy. "Development and application of linked hydrodynamic-water quality models for small lakes, reservoirs, and tidal inlets." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ31528.pdf.
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Bryant, Lee Davis. "Dynamic forcing of oxygen, iron, and manganese fluxes at the sediment-water interface in lakes and reservoirs." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77337.
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The National Research Council recently called for a more interdisciplinary approach to drinking water research to address the critical issue of global drinking water supplies. Hypolimnetic oxygenation systems (HOₓ) are being increasingly used to improve water quality in stratified reservoirs by increasing dissolved oxygen (O₂) concentrations and subsequently suppressing the release of soluble species such as iron (Fe) and manganese (Mn) from the sediment into the water. However, while the influence of HOx on the water column has been established, little work has been done on how oxygenation affects sediment O₂ uptake (i.e., sediment oxygen demand) and other sediment-water fluxes. In response to the growing need for alternative approaches for improving water quality, we conducted highly interdisciplinary research to evaluate how O₂, Fe, and Mn cycling at the sediment-water interface is influenced by both natural and HOx-induced variations in water column dynamics, chemical redox processes, and microbial activity within the sediment, all of which may govern sediment-water fluxes. Studies were performed in an alpine lake in Switzerland and in an HOₓ-equipped drinking-water-supply reservoir in Virginia. This research was based on in situ field campaigns paired with laboratory experiments, microbial analyses, and computer simulation to elucidate variable sediment O₂ uptake and corresponding Fe and Mn cycling. This work is unique in that sediment-water fluxes were assessed using in situ data from both sides of the sediment-water interface.
Results show that sediment O₂ uptake flux is strongly controlled by both wind- and HOₓ-induced dynamic forcing. Our findings reveal that Fe and Mn fluxes were suppressed from the bulk hypolimnion via biogeochemical cycling in the oxic benthic region. Results also indicate that the sediment microbial community structure may directly respond to HOₓ-induced variation in sediment O₂ availability. Additionally, based on an analysis of the robustness of several commonly used methods for flux calculations, we show that flux estimates are not strongly dependent on the method chosen for analysis. Ultimately, by emphasizing the highly transient nature of sediment O₂ uptake, this research will aid in accurate characterization of various sediment-water fluxes and corresponding water quality. Our results will also directly contribute to the optimization of HOₓ operations and lake and reservoir management.Ph. D.
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Abrahamse, Matthew S. "Abundance and structure of burbot Lota lota populations in lakes and reservoirs of the Wind River drainage, Wyoming." Laramie, Wyo. : University of Wyoming, 2009. http://proquest.umi.com/pqdweb?did=1797714301&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Krenz, Robert J. "Photopigments as descriptors of phytoplankton assemblages for biotic assessment of Illinois lakes and reservoirs : an HPLC aided analysis /." View online, 2009. http://repository.eiu.edu/theses/docs/32211131592143.pdf.
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Mehling, Molly Gail. "Nearshore littoral benthic macroinvertebrates of lakes and reservoirs in the western US: Multiscale community patterns and implications for bioassessment." Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1312555319.
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Resende, João Furtado. "Automated calibration of a Carbon dynamic model for lakes and reservoirs : (calibração automática de um modelo de dinâmica de Carbono em lagos e reservatórios)." reponame:Repositório Institucional da UFPR, 2017. http://hdl.handle.net/1884/49081.
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Orientador : Michael MannichCoorientador : Cristóvão Vicente Scapulatempo Fernandes
Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia de Recursos Hídricos e Ambiental. Defesa: Curitiba, 16/03/2017
Inclui referências e apêndices
Resumo: A carência de medidas de fluxos de gases de efeito estufa (GEE), junto com as incertezas referentes às extrapolações de emissões pontuais para emissões totais, resultam em conclusões imprecisas referente a participação de reservatórios no clima global. O modelo matemático CICLAR é usado para simular fluxos de CO2 e CH4 por 45 anos no reservatório de Capivari, Paraná, Brasil. O modelo é estruturado em compartimentos de diferentes formas de carbono, como o carbono inorgânico dissolvido (CID) e o carbono orgânico particulado vivo (COPL). Processos químicos de transferência de massa entre compartimentos são modelados como reações de primeira ordem e de saturação que são controladas por parâmetros numéricos. O valor destes parâmetros são calibrados através da minimização de diferenças entre dados observados e modelados através de algoritmos de calibração. O algoritmo metaheuristico de Otimização Multi-objetivo por Enxame de Particulas Combinada de Pareto (CPMOPSO), que combina técnicas de seleção de líderes, mutações e subenxames, foi desenvolvido e aplicado como método de otimização. O algoritmo de calibração automática utiliza dados provenientes da calibração manual. Quatro cenários foram analisados: o avaliativo, que usa os primeiros 30 e os últimos 15 anos de dados do reservatório para calibrar e validar o modelo; e o retrospective, o prospectivo e o ideal, que usam 9 anos de dados, distribuídos de maneiras diferentes, para calibrar o modelo. A qualidade dos resultados da calibração foi positivamente considerada através do uso do cenário avaliativo. Os resultados da calibração sob os cenários retrospectivo e prospectivo mostraram que o algoritmo tende a superestimar emissões de metano se dados mal distribuídos são utilizados. A otimização sob o cenário ideal obteve melhores resultados e mostrou que a disposição dos dados tem maior impacto do que a quantidade sobre a calibração. Todas as soluções sob todos os cenários obtiveram soluções com coeficientes de Nash-Sutcliffe superiores a 0.95 para o período de calibração. As distribuições acumuladas das médias dos Potenciais de Aquecimento Global (GWP) mostraram que a maioria das soluções calibradas classificam o reservatório como um sumidouro de dióxido de carbono equivalente, absorvendo até 90 Gg de CO2 eq. Estimativas alternativas de estoque de carbono foram utilizadas para calibrar o modelo em um escopo em que nenhuma solução prévia é conhecida. São feitas considerações adicionas referentes a aplicação de métodos de análise de incertezas e agregação Bayesiana para melhor aferir múltiplos conjuntos de parâmetros. Palavras-chaves: Modelagem matemática. Dinâmica do carbono. Gases de efeito estufa. Potencial de aquecimento global. Enxame de partículas. Dominância de Pareto.
Abstract: The low availability of measured greenhouse gas (GHG) fluxes for lakes and reservoirs, coupled with uncertainties regarding extrapolating total reservoir emissions from point measurements, result in inaccurate conclusions regarding the role of reservoirs in the global climate. The Carbon Cycle in Lakes and Reservoirs (CICLAR) model is used to study potential contributions, through carbon dioxide (CO2) and methane (CH4) emissions, of the Capivari reservoir, Brazil, since its construction in 1970. The model is structured in compartments for different carbon forms, such as dissolved inorganic carbon (DIC) and live particulate organic carbon (POCL), and model chemical processes as first order reactions controlled by numerical parameters. The values of these parameters are calibrated by minimizing differences between original and modeled data through an optimization algorithm. The Combined Pareto Multi-objective Particle Swarm Optimization (CPMOPSO) metaheuristic algorithm, which combines leader selection, mutation and subswarm techniques, is developed and successfully used as the optimization technique. The automated calibration algorithm uses data originated from the manual calibration. Four calibration scenarios are used to analyze the impact of data disposition in the calibration results: the evaluative scenario that has the initial 30 years to calibrate and the final 15 to validate the model; and the retrospective, prospective and ideal scenarios, that uses 9 years of data differently distributed. The evaluative data scenario is used to assess the quality of the calibration results, which successfully fit the validation data. The retrospective and prospective scenario are used to analyze the performance of the calibration under unevenly spread data, and the results show that the model had a bias to overestimate methane emissions. The calibration under the ideal scenario is used to show that having evenly spread data has a bigger impact on calibration results than having larger amounts of data. All calibrated solutions for all scenarios present Nash-Sutcliffe coefficient values higher than 0.95 for the calibration period. The cumulative distribution of average Global Warming Potential (GWP) indexes shows that most calibrated solutions estimated that the Capivari reservoir is a sinkhole for equivalent carbon dioxide and that it can absorb up to 90 Gg of equivalent CO2. Alternative carbon stock estimations are used to calibrate the model under a framework in which the results cannot be validated due to no previous solutions being known. Further consideration are drawn regarding the application of uncertainty analysis and Bayesian aggregation methods to better assess the combination of multiple set of parameters. Keywords: Mathematical modeling. Carbon dynamics. Greenhouse gases. Global warming potential. Particle swarm optimization. Pareto dominance.
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Stimson, Andrew Graham. "Fluvial carbon dynamics in degraded peatland catchments." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/fluvial-carbon-dynamics-in-degraded-peatland-catchments(94f066bd-cf18-4de3-9e4f-339476994fbf).html.
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Inland waters including streams, rivers, reservoirs and lakes are regarded as a significant site of Organic Carbon (OC) cycling, and greenhouse gas production. As a result, there has been significant recent interest in the rates and fate of fluvial carbon exported from organic soils, such as peatlands. Additionally, peatlands can be subject to substantial degradation resulting in high rates of fluvial OC export, and this has led to efforts to repair degraded peatlands through restoration programmes. As a consequence, the study of degraded areas is useful to quantify the upper values of carbon release, understand processes of transformation, and evaluate the success of restoration programmes. Importantly peatlands are also collection areas for drinking water, which has implications for treatment, and requires better understanding of carbon cycling upstream of treatment works, in headwater rivers, reservoirs and pipes. UK upland blanket peat catchments are a key location in which to consider global questions surrounding fluvial carbon export and transformations, as they are highly degraded, provide a source of drinking water supply, and are currently undergoing pioneering methods of landscape scale restoration. This thesis considers Kinder Scout, an area of highly degraded and gullied blanket peatland in the South Pennines, UK. Using analysis of water samples collected over several years in the Kinder reservoir catchment and plateau, this thesis presents three novel contributions to global questions concerning OC cycling and peatlands. Firstly it provides (to date), the only carbon budget for a reservoir in a peat dominated catchment with high Particulate Organic Carbon (POC) export, which demonstrates that reservoirs may be net sources of Dissolved Organic Carbon (DOC), with the implication that POC-DOC interactions are important OC transformation mechanism in degraded systems. Secondly through use of a unique integrated combination of methods, it considers changes in carbon flux and composition in both river, lake and pipe locations, providing detailed understanding of the relative roles of river reaches, reservoirs and supply pipes, in controlling fluvial carbon cycling in peatland systems, and upstream of water treatment works. An important implication here, is that rate and direction of change in water treatability varies through a catchment. Finally, it includes results from the first widespread monitoring of the catchment scale effects of a new method of peatland revegetation. This restoration approach is being applied at landscape scale and the findings here, are that despite fears to the contrary, it does not lead to short term increases in fluvial carbon loss, which is an important piece of evidence supporting practical conservation approaches in these systems. To further enhance this research, a combination of field and laboratory investigations into carbon transformation processes, and ongoing restoration mentoring should be undertaken.
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Dickey, Richard Jason Bayne David Roberge. "Oligotrophication effects following diversion of waste effluent from an embayment of Lake Martin, Alabama." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Fall/Theses/DICKEY_RICHARD_7.pdf.
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Graham, Philip Mark. "Modelling the water quality in dams within the Umgeni Water operational area with emphasis on algal relations / Philip Mark Graham." Thesis, North-West University, 2007. http://hdl.handle.net/10394/1022.
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Based on many years of water quality (including algal) and water treatment cost data,
available at Umgeni Water, a study was undertaken to better understand the water
quality relationships in man made lakes within the company's operational area, and
to investigate how water quality affected the cost of treating water from these lakes.
The broad aims to the study were to:
identify the key environmental variables that were affecting algal populations
in lakes; and if these were significant to
establish predictive models relating algae to the water quality; and to
develop models relating the water quality in lakes to the cost of treating water
from the lakes.
Semi-quantitative models were developed relating algal abundances with important
environmental variables. In most cases, the models developed were related to algal
populations that were known to adversely affect water treatment. Direct algal impact
on water treatment processes was through the production of either taste and odour
forming compounds (requiring advanced water treatment, such as use of activated
carbon), or their ability to clog sand filters and so reduce filter run times (requiring
more frequent backwashing of filters).
Thereafter lake water quality parameters (which included water physico-chemistry
and algae) were investigated to determine which factors were most significantly
impacting on water treatment and hence treatment costs at selected water works
(WW) within the Umgeni Water operational area. Models were developed relating
raw water quality entering respective water works with costs incurred in treating that
water. The models allowed simulations to be developed illustrating how changes in
water quality might impact on water treatment costs. The impact of eutrophication
and contamination of rivers and lakes, and its subsequent impact on surface water
resources, was quantified.Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2004.
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Mi, Chenxi [Verfasser], Dietrich [Gutachter] Borchardt, Thomas U. [Gutachter] Berendonk, and Karsten [Gutachter] Rinke. "Assessing climate change impacts on physical structure of lakes and reservoirs using one, two and three-dimensional hydrodynamic models / Chenxi Mi ; Gutachter: Dietrich Borchardt, Thomas U. Berendonk, Karsten Rinke." Dresden : Technische Universität Dresden, 2020. http://d-nb.info/1227833091/34.
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Rodrigues, Sonia Luiz. "Comparação da atenuação da radiação solar e dos fatores que determinam o clima de radiação solar subaquática em lagos e reservatórios do Brasil." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-23092003-112001/.
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O estudo da penetração da radiação solar no meio aquático foi desenvolvido em quatro partes. Na primeira delas, voltada para a atenuação da radiação solar na coluna dágua, foram discutidos fatores de interferência e suas inter-relações. Neste sentido, foi feita uma comparação da penetração da radiação solar em ecossistemas continentais naturais e artificiais, analisando as diferenças e similaridades. O estudo comparativo da atenuação da radiação solar subaquática em toda extensão de reservatórios constituiu a segunda parte deste trabalho. A comparação foi feita entre reservatórios que apresentam proximidades de localização, mas com diferenças marcantes nos usos e ocupações nas regiões em que os mesmos estão inseridos. Na terceira parte foram apresentados dois recursos de grande utilização na obtenção das respostas imediatas do ambiente aquático, do ponto de vista óptico, diante dos impactos sofridos. O primeiro recurso foi a determinação do espectrograma da radiação solar, indicando a atenuação da radiação solar subaquática na faixa fotossinteticamente ativa (400 nm - 700 nm). O outro recurso foi a obtenção do espectro de absorção da água superficial, que permitiu o estabelecimento do Índice de Absorção Espectral da Água, I.A.E.A., que facilmente possibilita a detecção de fontes pontuais de poluição e contaminação. Como quarta e última parte foi proposto o desenvolvimento de um aparelho a partir da reconstrução do hidrofotômetro (Modelo Nº 268 WA 310 GM MFG & Instrument Corp. Bronx. N.Y. 10 451), onde foi introduzido e adaptado o detector fotocondutivo (PIN - 250DP) em substituição às fotocélulas anteriormente danificadas. Durante o trabalho de campo, este aparelho foi testado e foi feita a comparação com os obtidos do Quanta-meter LI-COR (LI - 185A) também utilizado neste trabalho.The study of solar radiation penetration in aquatic environment was developed in four parts. The first one, directed to solar radiation attenuation in the water column, interference factors and their inter-relations were discussed. In this sense, a penetration comparison of the solar radiation in natural and artificial continental ecosystems was carried out, analyzing differences and similarities. The second part of this work consisted of a comparative study of underwater solar radiation in the entire reservoir. The comparison was done between reservoirs that are near to one another, but with marked differences in use and occupation within the regions where they are located. In the third part, two resources of great utilization in obtaining immediate response from the aquatic environment, from an optical point of view of the impacts experienced, were presented. The first resort was the spectrogram determination of solar radiation, which indicated the underwater solar radiation attenuation in the active photosynthetic range (400 nm - 700 nm). The other resort was the superficial water absorption spectrum, which allowed establishing the Water Spectral Absorption Index, I.A.E.A. that easily makes possible detection of accurate sources of pollution and contamination. The fourth and last part proposed to develop an apparatus from the construction of an underwater hydrophotometer (Model 268 WA 310 GM MFG & Instrument Corp. Bronx N.Y. 10451), where the photoconductor detector was adapted and introduced (PIN - 250DP) substituting the previously damaged photocells. During field work, this apparatus was tested and comparison was performed with data obtained from Quanta-meter LI-COR (LI - 185A), also used in this work.
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Tavares, Katia Sendra. "A comunidade de macrófitas aquáticas em reservatórios do médio e baixo Rio Tietê (SP) e em lagos da bacia do médio Rio Doce (MG)." Universidade Federal de São Carlos, 2002. https://repositorio.ufscar.br/handle/ufscar/2060.
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Previous issue date: 2002-02-26Universidade Federal de Sao Carlos
Macrophytes have a fundamental role in the functioning of aquatic ecosystems due to their high primary productivity, participation in the nutrient cycling, and interactions with many other components of the system. Many species of macrophytes can be bioindicator of the trophic state or succession stage of the system. In the present work the macrophyte communities of twelve lakes in the Middle Rio Doce (MG) and a cascade of six reservoirs (SP) were analysed, comparing systems naturally and artificially fragmented. Four sampling expeditions to the Rio Doce system and three to the Tietê were performed during the 2001 2002 period. The macrophyte species present were recorded, photographed and collected for herborization. The community was analysed in relation to the species richness, dominant species, the frequence of occurrence and the species composition similarity, intra and inter lake and reservoir systems. The relationship between species richness and lake morphometry was also analised. Macrophyte biomass was determined for selected stands, in order to verify the existence of temporal variations. In the lakes of Middle Rio Doce system a total of 53 species were registered, belonging to 25 genera and 23 families. The occurrence of Habenaria fastor Hoene (Orchidaceae) in this system of lakes was recorded for the first time. The highest richness occurred in the lakes Barra and Verde. Species composition varied considerably among lakes and between periods. No statistically significant relationships were found between species richness and variables related to lake morphometry, although a tendency of increase in the species richness as a function of the increase in the area and perimeter of the lakes was observed. In Tietê reservoirs a total of 48 species were found, belonging to 26 genus and 22 families. The species composition in the first three reservoirs (Middle Tietê) differed from that on the last three reservoirs (Low Tietê). The relationship among the species richness and reservoir morphometry was not statistically significant, however there was a tendency of decreasing richness as the reservoir area or perimeter increased. Twenty three species were shared among both systems; 23 exclusively on lakes of Middle Rio Doce and 18 exclusively in on Tietê reservoirs. The families Cyperaceae and Onagraceae were the ones represented by the highest number of species in both systems. Marked differences were found between the studied systems. The macrophyte species richness was higher in the Middle Rio Doce lakes than in the Tietê reservoirs. In the lakes the increase in the area and perimeter were factors directly related to the increase in species richness whereas in the reservoirs this relationship was inverse. Biomass of macrophytes in selected stands varied greatly between periods, however total biomass per areal unity was similar, although the highest values were recorded in Nova Avanhandava and Ibitinga reservoirs. The results of this study have indicated that the lakes of Middle Rio Doce being a naturally fragmented system, ancient and stable, have a higher macrophyte diversity, whereas the Tietê reservoirs, recently and artificially fragmented and also with greater instability have a lower diversity. Also, the species richness in the reservoirs appeared to be not directly related to the area and perimeter, variables which are representative of their most propitious habitats in natural systems.
As macrófitas aquáticas têm papel fundamental no funcionamento dos sistemas aquáticos devido às suas elevadas taxas de produtividade primária, importância na ciclagem de nutrientes e interações com diversos outros componentes do sistema. Muitas macrófitas podem ser bioindicadoras do grau de trofia ou do estágio sucessional do sistema. O presente trabalho analisou as comunidades de macrófitas aquáticas de doze lagos do médio rio Doce (MG) e de seis reservatórios em cascata no médio e baixo rio Tietê (SP), comparando sistemas fragmentados de forma natural e artificial. Foram realizadas quatro amostragens no médio rio Doce e três no médio e baixo rio Tietê, durante o período de 2001 a 2002. As espécies de macrófitas presentes foram registradas, fotografadas e coletadas para herborização. A comunidade foi analisada quanto à riqueza de espécies, espécies predominantes, freqüência de ocorrência, similaridade da composição de espécies dentro e entre os sistemas e quanto às possíveis relações com o estado trófico dos ambientes e com as variáveis morfométricas. A biomassa foi determinada para determinados bancos de macrófitas, visando observar a variação temporal da mesma. Para os lagos do médio rio Doce foram registradas 53 espécies, distribuídas em 25 gêneros e 23 famílias. A ocorrência de Habenaria fastor Hoene (Orchidaceae) foi registrada pela primeira vez neste sistema de lagos. A maior riqueza de espécies ocorreu nas lagoas da Barra e Verde. A composição de espécies variou consideravelmente entre os lagos e entre as épocas. Não foram verificadas relações estatisticamente significativas entre a riqueza de espécies e as variáveis morfométricas,embora tenham sido observadas tendências de aumento da riqueza de espécies em relação ao aumento da área e do perímetro dos lagos. Para os reservatórios do médio e baixo rio Tietê foram encontradas 48 espécies, pertencentes a 26 gêneros e 22 famílias. A composição de espécies nos três primeiros reservatórios (Médio Tietê) foi bastante diferenciada daquela dos três últimos (baixo Tietê). As relações entre a riqueza de espécies e as variáveis morfométricas não foram estatisticamente significativas, notando-se, porém, uma tendência de diminuição da riqueza em função do aumento da área e do perímetro dos reservatórios. Foram encontradas 23 espécies comuns aos dois sistemas; 23 exclusivas dos lagos do médio rio Doce e 18 exclusivas dos reservatórios do rio Tietê. Em ambos os sistemas as famílias Cyperaceae e Onagraceae estiveram representadas por maior número de espécies. Foram constatadas diferenças significativas entre os dois sistemas estudados. A riqueza de espécies foi maior para os lagos do médio rio Doce do que para os reservatórios do médio e baixo Tietê. Para os lagos o aumento da área e perímetro constituíram fatores diretamente relacionados ao aumento da riqueza de espécies enquanto para os reservatórios essa relação foi inversa. Os valores de biomassa para bancos de macrófitas amostrados nos dois sistemas mostraram variações acentuadas entre os períodos, contudo a biomassa por unidade de área foi similar, sendo os maiores valores registrados nos reservatórios de Nova Avanhandava e Ibitinga. Este estudo indica que os lagos do rio Doce sendo sistemas naturalmente fragmentados, antigos e estáveis contêm uma maior diversidade de macrófitas aquáticas enquanto os reservatórios oriundos de fragmentação artificial e recente, e por serem mais instáveis contêm menor diversidade de macrófitas e não diretamente correlacionadas com as variáveis morfométricas representativas dos habitats propícios às mesmas em ambientes naturais, como a área e o perímetro.
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Chang, Yan. "Impacts of Climate Changeson Reservoirs in Northern Sweden : case study of Akkajaure reservoir by modelling." Thesis, Linköpings universitet, Tema vatten i natur och samhälle, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-68419.
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Since the middle of the 20th century, the average temperature of the atmosphere near Earthsurface has increased. The global warming causes many effects in hydrological systems, suchas changes in thermal structure, water quality, aquatic ecosystems, etc. This thesis studies theimpact of climate change on Akkajaure reservoir, the second largest regulated reservoir inSweden, by simulating a predicted temperature rise based on the climate and hydrologicalconditions of Akkajaure in 1998-2002. The congeal duration, ice thickness and the turbulentkinetic energy (TKE) in the lake were calculated by the catchment hydrological model and thelake model. The movement of phytoplankton and their mean net production (MeanNP) rateare simulated by the dispersion model and the photosynthesis model. By comparing thesimulation results of past situation and three predicted scenarios, it is obtained that theincreases of temperature shorten the congeal duration, which is a lead factor for shortening thetrough period and amplification of peak value of TKE. The comparison of plankton particlesposition illustrates that the particles stay in a deeper position for a longer time because of thechanges of TKE. Though the plankton stays in euphotic zone longer as the temperatureincreases, the comparison of the mean production rate between the real scenario and thepredicted scenarios concludes that the mean production rate grows as the temperatureincreases because the shortened ice cover period makes the duration of absorbed sunlightincreases in lake. The effects of global warming may influence the distribution of microalgaein on high latitude lakes and reservoirs. The phytoplankton will stay in deeper water layers fora longer time.
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Sachse, René. "Influence of climate change on lake ecosystems - disentangling physical, chemical and biological interactions." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-167312.
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Climate change affects lake ecosystems in many ways by direct and indirect temperature impacts on hydrophysical structure, hydrology, chemical cycles and on biological interactions. The identification of these climate signals can be complicated and superimposed by other environmental changes, such as land use changes. The aim of this thesis was to seperate temperature effects from effects of management and other environmental influences and to understand the underlying complex processes causing significant changes of ecosystem states. This understanding is important for decisions of lake and reservoir managers to counteract unfavorable consequences of climate change. For the recent study, long-term data of meteorological, hydrophysical and biological variables (phytoplankton, crustacean zooplankton, fish) of the German drinking water reservoir Saidenbach were analysed. Based on this long-term data set, strong indicators for climate induced changes have been identified. In particular, increasing water temperatures since 1975, earlier break up of ice covers and an altered hydrophysical structure could be detected. Thereby, stratification stability increased and turbulent mixing decreased in summer. The water of the reservoir warmed more than the tributaries resulting in a trend to deeper entrainment of the inflows. As further indicators of climate change, an increased annual biomass of phytoplankton and species shifts in the phytoplankton community in spring and summer had been observed. During the spring mass development, the diatom Aulacoseira subarctica became dominant in recent years with warm winters and early ice-out. Its unusual spatial pattern with occurrences in aphotic depths could be explained by easier resuspension compared to other diatoms. By being resuspended first and establishing a high inoculum, A. subarctica profits from an earlier ice-out and earlier full circulation. In spite of a reduced nutrient loading to the epilimnion, in summer, the diatom Fragilaria crotonensis was displaced increasingly by cyanobacteria. This species shift could be explained well by the hydrophysical regime shift. Although, the annual total phytoplankton biomass increased since 1990, the crustacean zooplankton in Saidenbach reservoir did not seem to profit from improved food resources. To the contrary, Daphnia abundances reduced tremendously. We could show that the influcence of fish stocks were underestimated. The stocked silvercarp may have contributed up to 70 % of the total zooplanktivorous fish biomass which had a temperature and density dependent effect. The faster growth of Daphnia at higher temperatures could not compensate for the more actively grazing fish when stock of zooplankitvorous fish was too high. Still, temperature was identified as the most important factor that explained 29 % of the zooplankton phenology, while the second most important predictors were zooplanktivorous fish biomass and nutrient loading, explaining 18 % of the variance. The importance of submerged macrophytes in shallow lakes is well investigated. To increase also the understanding of their impact and their role during climate change on water quality in deep lakes, a model for stratified lakes that includes submerged macrophytes was developed. The simulations showed that macrophyte effects were mainly positive for water quality and macrophytes in deep lakes were able to potentially reduce summer phytoplankton, especially cyanobacteria by 50 % in 11 m deep and still by 15 % in 100 m deep oligotrophic lakes. Nutrient competition with phytoplankton contributed most to this macrophyte effect. In conclusion, for deep lake restoration the re-establishment of submerged macrophytes might be as important as for shallow lakes. The full lake model includes hydrophysical and ecological submodules and thus will allow further comprehensive climate simulations and the evaluation of the effectivity of adaptive strategies and scenarios for deep lakes and reservoirsDer Klimawandel beeinflusst Seeökosysteme vielfältig durch direkte und indirekte Temperatureffekte auf die hydrophysikalische Struktur, die Hydrologie, chemische Kreisläufe und biologische Interaktionen. Die Identifikation von Klimasignalen kann durch Landnutzungs- und weitere Umweltveränderungen überlagert werden. Ziel dieser Arbeit war es, Temperatureffekte von Effekten zu unterscheiden, die durch Gewässermanagement oder anderen Umweltveränderungen verursacht werden. Weiterhin sollten komplexe Prozesse verstanden werden, die zu signifikanten Veränderungen in Seeökosystemen führen. Dieses Verständnis ist für Talsperren- und Gewässermanager von besonderer Bedeutung, um ungewünschten Folgen des Klimawandels entgegenwirken zu können. Für die Studie wurden Langzeitdaten für meteorologische, hydrophysikalische und biologische Variablen (Phytoplankton, Crustaceen-Zooplankton, Fischbesatz) der Talsperre Saidenbach ausgewertet. Mehrere Indikatoren für die Auswirkungen des Klimawandels konnten basierend auf diesen Daten identifiziert werden. Diese gehören insbesondere eine Erhöhung der Wassertemperatur seit 1975, zeitigere Eisaufbrüche und eine veränderte Schichtungsstruktur. Dabei wurde im Sommer die Schichtungsstabilität höher und die Intensität der Durchmischung geringer. Das Wasser in der Talsperre erwärmte sich stärker als die Zuflüsse, wodurch diese sich zunehmend tiefer und unterhalb der Thermokline einschichten. Eine zunehmende jährliche Phytoplanktonbiomasse und Artenwechsel innerhalb der Planktongemeinschaft sind weitere Indikatoren für Klimafolgen. Die Kieselalge Aulacoseira subarctica erlangte in Jahren mit warmen Wintern und zeitigen Eisaufbrüchen eine Dominanz während der Frühjahrsentwicklung. Das ungewöhnliche Auftreten dieser Art in aphotischen Tiefen konnte durch eine leichtere Resuspension im Vergleich zu anderen Kieselalgen erklärt werden. Durch zeitige Resuspension gleich nach Eisaufbruch kann A. subarctica ein hohes Inokulum etablieren. Trotz reduzierter Nährstoffzufuhr ins Epilimnion wurde im Sommer die Kieselalge Fragilaria crotonensis vermehrt durch Cyanobakterien verdrängt, was jedoch gut mit den Änderungen der hydrophysikalischen Struktur erklärt werden kann. Obwohl seit 1990 insgesamt mehr Phytoplankton zur Verfügung steht konnte das Crustaceen- Zooplankton in der Talsperre Saidenbach nicht von diesen verbesserten Nahrungsbedingungen profitieren. Die Daphnia-Abundanzen waren seit 1990 stark verringert. Es konnte gezeigt werden, dass der Einfluss des Fischbesatzes unterschätzt wurde und die künstlich ins System eingebrachten Silberkarpfen zeitweise bis zu 70% der zooplanktivoren Fischbiomasse ausgemacht haben. Zoo- planktivore Fische haben einen temperatur- und dichteabhängigen Effekt auf das Zooplankton. Das schnellere Populationswachstum von Daphnia kann bei hohem Besatz mit zooplanktivoren Fischen nicht die erhöhte Fraßaktivität der Fische ausgleichen. Dennoch konnte Temperatur als der wichtigste Einflussfaktor auf die Phänologie des Zooplanktons identifiziert werden, gefolgt von zooplanktivorem Fisch und Nährstoffzufuhr. Die Wichtigkeit von submersen Makrophyten in Flachseen ist gut untersucht. Um den Einfluss von Makropyhten auf die Wasserqualität während des Klimawandels auch in tiefen Seen abschätzen zu können, wurde ein komplexes Seemodell entwickelt. Die Simulationen zeigen, dass sich Makrophyten hauptsächlich positiv auf die Wassergüte auswirken und zur Reduktion von Phytoplankton, insbesondere von Cyanobakterien im Sommer, beitragen. In einem 11 m tiefen See betrug die Reduktion 50 %, in 100 m tiefen oligotrophen Seen immer noch 15 %. Die Konkurrenz um Nährstoffe mit dem Phytoplankton war dabei die ursächliche Makrophyten-Plankton-Interaktion. Submerse Makrophyten könnten für die Restaurierung von tiefen Seen folglich genauso wichtig sein, wie für Flachseen. Das komplette Seemodell enthält hydrophysikalische und ökologische Module und ermöglicht damit weitere umfassende Simulationen zur Untersuchung der Auswirkungen des Klimawandels und zur Evaluation von Adaptionsstrategien für Seen und Talsperren
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Stott, A. P. "Reservoir sedimentation and land use change in north west England." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379152.
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Clifford, Philip A. (Philip Alan). "Aquatic Vegetation Nutrient Budgets and Sedimentation in a Southwestern Reservoir." Thesis, North Texas State University, 1986. https://digital.library.unt.edu/ark:/67531/metadc504467/.
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During four growing seasons, aquatic vascular plant production and distribution were studied in Pat Mayse Lake, Texas, a 2425 hectare oligo-mesotrophic reservoir. The dominant macrophyte population was Myriophyllum spicatum L. Growth rates and regrowth rates of mechanically harvested Myriophyllum beds were found to be dissimilar. Based on estimates of watermilfoil nutrient content, there were insufficient nutrients in the entire population to alter the trophic status of this reservoir should all of the nutrients be instantaneously released. Sediments were the primary nutrient (nitrogen and phosphorus) sink. Bank erosion and solids transport from the watershed appear to contribute most of the sediments and a lake-wide mean sedimentation rate of 2.5 cm/year was estimated from sediment trap and core sample data.
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Williams, Nicholas T. "Modeling dissolved oxygen in Lake Powell using CE-QUAL-W2 /." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1755.pdf.
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Almeida, Caio Augusto de. "Aspectos do ciclo de vida de espécies bentônicas nativas e sua utilização na avaliação da qualidade de sedimentos de lagos naturais e reservatórios." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-29082007-210238/.
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Os estudos ecológicos, com vistas para a conservação do meio ambiente, vêm sendo intensificados desde meados do século XX. Devido à integração com várias outras ciências durante o processo de formação do conhecimento ecológico, esses estudos têm se tornado essenciais para o desenvolvimento de tecnologias e de políticas adequadas ao gerenciamento dos recursos naturais, em especial dos recursos hídricos. Estudos que contemplem a comparação entre sistemas naturais e artificiais são importantes na medida em que permitem investigar como esses sistemas reagem a perturbações antropogênicas de curto ou longo prazo. Há um consenso geral de que a camada de sedimento dos corpos d\'água desempenha um papel fundamental na dinâmica de transporte, acumulação e disponibilização de contaminantes nesses sistemas. A tríade de qualidade de sedimento é considerada uma das melhores abordagens para o estudo de sistemas aquáticos impactados por efluentes oriundos de atividades antrópicas. Habitats dulcícolas são particularmente suscetíveis à introdução de espécies exóticas de invertebrados. Uma possível rota de introdução dessas espécies é o cultivo em laboratório para testes de toxicidade. Substituí-las por espécies nativas com sensibilidade similar pode prevenir a introdução acidental de espécies exóticas, além de facilitar a obtenção de inóculos para as renovações da cultura, e de serem mais significativos na extrapolação dos resultados laboratoriais para situações em campo. Duas espécies nativas de organismos bentônicos foram estudadas com relação à aspectos de suas biologia e a adequação como organismos-teste em ensaios ecotoxicológicos: Chironomus xanthus (Díptera) e Branchiura sowerbyi (Oligochaeta). Os resultados dos testes de toxicidade ao pentaclorofenol para C. xanthus permitiram calcular uma CL50 (96h) de 0,111 mg/L com uma faixa de sensibilidade entre 0,082 e 0,141 mg/L. Os testes de sensibilidade de B. sowerbyi ao cloreto de potássio resultaram em uma CL50 (96h) de 0,364 g/L com uma faixa de sensibilidade entre 0,177 e 0,551 g/L. Realizou-se também um balanço energético geracional cumulativo para C. xanthus, obtendo-se os seguintes valores para as eficiências metabólicas calculadas: coeficiente instantâneo de assimilação de 98,14%, coeficiente de produção bruta de 14,76% e coeficiente de produção líquida de 15,03%. Além dos ensaios toxicológicos com os dois organismos, realizou-se um estudo comparativo entre o sistema de reservatórios em cascata do rio Tietê com o sistema de lagos naturais do Vale do Rio Doce, aplicando-se os princípios da tríade de qualidade de sedimentos. Os resultados dessa análise permitiram classificar os reservatórios estudados de acordo com o nível de qualidade ambiental sendo que o reservatório de Barra Bonita (SP) é considerado como o de pior qualidade, enquanto que os lagos do Vale do Rio Doce (MG) encontram-se ainda relativamente preservados.The ecological studies, with views for the conservation of the environment, have been intensified from middles of the century XX. Due to the integration with several other sciences during the process of ecological knowledge formation, those studies have become essential to the development of technologies and appropriate politics for the administration of the natural resource. Studies that contemplate the comparison among natural and artificial systems are important in the way it is allowed to investigate as those systems react to antropogenic disturbances of short or long periods. There is a general consensus that the sediment of the water bodies plays a fundamental part in the transport dynamics, accumulation and disposal of pollutants in these systems. The triad of sediment quality is considered one of the best approaches for the study the influence of pollutants originated from of human activities in aquatic ecossystems. Freshwater habitats are particularly susceptible to the introduction of exotic species of invertebrates. A possible route of introduction of those species is the cultivation in laboratory for toxicity tests. To substitute them for native species with similar sensibility can prevent the accidental introduction of exotic species, besides facilitating the inocula obtaining for the renewals of the culture, and may be more significant in the extrapolation of the laboratories results for field situations. Two native species of benthic organisms were studied regarding to aspects of their biology and the adaptation as organism-test in ecotoxicological assays: Chironomus xanthus (Díptera) and Branchiura sowerbyi (Oligochaeta). The results of the toxicity tests to the pcp for C. xanthus allowed to calculate a LC50 (96h) of 0,111 mg/L with a sensitivity range of 0,082 - 0,141 mg/L. The sensitivity testes for B. sowerbyi to the KCl resulted in a LC50 (96h) of 0,364 g/L with a sensitivity range of 0,177 - 0,551 g/L. An energy budget of C. xanthus was performed, being obtained the following values for the calculated metabolic efficiencies: instantaneous coefficient of assimilation of 98,14%, coefficient of production of 14,76% and coefficient of liquid production of 15,03%. A comparative study among the system of reservoirs in cascade of the Tietê river with the system of natural lakes of Rio Doce valley was applied following the principles of the triad of quality of sediments. The results of that analyze allowed to classify the reservoirs studied in agreement with the level of environmental quality and the reservoir of Barra Bonita (SP) is considered as the one of worse quality, while the lakes of Rio Doce Valley (MG) still meet relatively preserved.
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Belinsky, Tammy L. "The effects of lake dymanics on the water quality of Abel Lake Reservoir." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43832.
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The Abel Lake Reservoir in Stafford County, Virginia, was investigated to evaluate the lake's temporal and spatial dynamics with respect to water quality and water treatment problems. A limnological survey was conducted. The survey included all conventional parameters for the characterization of hydrodynamics and lake-water quality.
Abel Lake was found to be a typical temperate-zone lake that stratifies thermally in the summer, and the hypolimnetic water quality subsequently degrades with the depletion of oxygen. The lake then circulates in the fall in a process that begins in the shallow, upstream area of the lake and progresses downstream gradually until the deepest regions have circulated. The circulation process brings poor quality water from the hypolimnion to the surface where it is drawn into the treatment facility and creates treatment problems.
Results also show that algal growth and nutrient concentrations were moderate during the study, however, the potential for cultural eutrophication is present should unmonitored development of the watershed occur.Master of Science
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Eggink, Judith. "An Investigation of the Limnological Dynamics of Lake Manassas." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/36059.
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Lake Manassas, located in the Occoquan Watershed in Virginia is a man-made impoundment of the Broad Run river. This lake surface area is approximately 697 acres, and it drains approximately 46,500 acres. Currently, the reservoir supplies drinking water to the City of Manassas and some areas of Western Prince William County, but if necessary, can help supply drinking water to 750,000 people in the Northern Virginia area.
Since 1984, the Occoquan Watershed Monitoring Laboratory has been sampling seven streams and eight lake stations as part of a program funded by of the City of Manassas. Lake Manassas is an important drinking water resource for the City and the surrounding areas and is used for recreational purposes as well. It is extremely important to continuously monitor the lake closely so that any6 undesirable trends in water quality may be detected and addressed. Currently surrounding the lake are two golf courses, with two more golf courses planned for the future, as well as homes, and recreational areas.
Overall, Lake Manassas is still considered to be eutrophic, which is the same conclusion reached in previous reports. The main nutrient source is Broad Run, but there are other smaller sources as well that are of concern. South Run has decreased nutrient loadings since the last report in 1996. Another conclusion is that the lake is Phosphorus-limited, but at times, the lake comes close to being nitrogen-limited.Master of Science
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Radford, Wilbur Edward. "Relocation of earthquakes in the Lake Sinclair reservoir area." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/25807.
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Du, Feu Timothy Avon. "Tropical reservoir fisheries : Lake Kainji, Nigeria: a case study." Thesis, University of Hull, 2003. http://hydra.hull.ac.uk/resources/hull:5505.
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Dodson, Susan Boyd. "Eutrophication Potential of Reclaimed Wastewater: An Ecological Study of Water Reuse in an Urban Texas Reservoir." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc935568/.
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This study determined effects of addition of secondarily treated municipal wastewater effluent on an urban reservoir receiving system. Monthly water quality monitoring of the receiving reservoir and the wastewater, chemical analysis, and monthly laboratory algal assays, were conducted from September 1984 to September 1985. The nutrient status and algal growth potential of the receiving water and the wastewater confirmed the biostimulatory properties of the wastewater. Field validation studies were conducted using limnocorrals. Tertiary treatment of the wastewater using chemical coagulation precipitation with alum and ferric chloride reduced phosphorus concentrations in the wastewater to levels which supported significantly less algal biomass than untreated wastewater. These studies indicate ferric chloride to be a more effective coagulant for phosphorous removal alum.
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Estrada, Miguel Angel. "The dynamics of the planktonic communities of two Oregon reservoirs." PDXScholar, 2000. https://pdxscholar.library.pdx.edu/open_access_etds/4307.
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From June 1998 to July 1999, the dynamics of the plankton in Hagg Lake and Barney Reservoir were studied with the purpose to identify the succession dynamics of the planktonic species, to test the Plankton Ecology Group (PEG) model, and to explore the relationships between these successions and the physical and chemical variables.
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Saji, Niffy. "Development of a Guide to Lake and Reservoir Zone Determination." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/31587.
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Reservoirs are generally created by damming rivers. The upper reaches of any reservoir is generally narrow and winding like the parent river. This is the riverine zone of the reservoir. The reservoir is deepest and widest near the dam. Here, lake-like conditions exist and the water is quiescent. This is the lacustrine zone. The transitional zone separates the lacustrine and riverine zone. It has intermediate characteristics.
There are many characteristics, both physical and chemical, that differentiate between these three zones. Based on the differences in characteristics between the three zones, a method has been developed to successfully divide any reservoir into three zones. The method developed was applied to Lake Manassas and the Occoquan Reservoir located in the Occoquan watershed in Virginia. Both are man-made impoundments.
Analysis of data, based on the method developed, was successfully in dividing both reservoirs into the three zones. This method may therefore be successfully applied to obtain zonation in reservoirs.
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Banks, Kenneth E. (Kenneth Edward). "Analysis of Phytoplankton Responses to Water Chemistry Dynamics in a Moderately Eutrophic North Texas Reservoir." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc278929/.
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Canonical correspondence analysis (CCA) was used to explore relationships between measured environmental variables and in situ phytoplankton communities in a moderately eutrophic North Texas Reservoir.
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Ambers, Rebecca Kelly Robinson. "Sedimentation, mercury contamination, and clay mineralogy of the Dorena Lake Watershed, Western Oregon /." view abstract or download file of text, 2000. http://wwwlib.umi.com/cr/uoregon/fullcit?p9978243.
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Thesis (Ph. D.)--University of Oregon, 2000.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 169-178). Also available for download via the World Wide Web; free to University of Oregon users.
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Holley, Michael Paul Maceina Michael J. "An evaluation of the catfish fishery in Wilson Reservoir, Alabama." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Fall/Theses/HOLLEY_MICHAEL_23.pdf.
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El-Arabawy, Mohsen Mohamed Mohamed. "Lake Nasser reservoir sedimentation estimates for various water resources planning alternatives." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342801.
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Watschke, Darin Allen. "Assessment of tributary potential for wild rainbow trout recruitment in Hebgen Reservoir, Montana." Thesis, Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/watschke/WatschkeD0506.pdf.
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Cassidy, Kelly Michela. "Use of Remote Sensing for Cover Type Interpretation Over the Ray Roberts Reservoir Area." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc798144/.
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As part of a pre-impoundment study for the Ray Roberts Reservoir Area, Landsat-5 multi-spectral scanner (MSS) imagery was used for cover type interpretation. This research was concerned with analysis techniques for MSS images and a comparison of results obtained using computer assisted interpretatin of MSS images and a comparison of results obtained using computer assisted interpretation of MSS images with those obtained using manual interpretation of false color infrared (CIR) photographs.
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McGinnis, Daniel Frank. "Two-Dimensional Lake and Reservoir Modeling: Natural and Plume-Induced Mixing Mechanisms." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/29395.
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Lakes and reservoirs exhibit a number of mixing and transport mechanisms. Understanding the transport is crucial to understanding and predicting constituent and density structures. Transport in waterbodies can be natural, such as seiche-induced boundary mixing or advectively-driven inflows. Hypolimnetic oxygenation using bubble-plumes also leads to enhanced mixing. Whether natural or plume-induced, increased mixing will alter the waterbody properties. Conversely, the density structure affects the behavior of plumes as well as inflowing and outflowing water. For example, stratification resulting from impounding a river can result in nutrient and suspended solids retention. Similarly, operation of plumes can induce mixing in the hypolimnion, resulting in warming, increased nutrient transport, and resuspension of settled particles.
Modeling is extremely useful in determining the effects of dams on water quality constituents, enhanced transport, and the performance of mitigation techniques, such as hypolimnetic oxygenation. In this work, a variety of modeling techniques are used to evaluate natural and man-made mixing mechanisms. These include simple temperature and mass budgets, a two-dimensional lake model, and a two-phase plume model.
A bubble-plume and plume-enhanced mixing was studied in Lake Hallwil. It was found that the plume-lake interaction was much more complex then previously expected, and knowledge of the seiche- and plume-enhanced near-field was necessary to accurately model the plume performance. A two-dimensional lake model was then coupled with a linear-plume model to accurately predict not only the plume performance, but also the plume-enhanced mixing in Spring Hollow Reservoir. The same two-dimensional lake model, used in conjunction with data analysis, demonstrated that the Iron Gate I Reservoir was not a significant sink for suspended solids, with only the large, adjacent side bay (Orsova Bay) thought to be the permanent sink. Furthermore, significant stratification did not develop, preventing substantial primary productivity. While the impoundment did change the water quality characteristics, the extent is much less than previously expected. The modeling methods presented here and the coupled plume-reservoir model should be useful tools for the design, modeling and greater understanding of bubble-plumes and other transport-related phenomena in lakes and reservoirs.Ph. D.
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高橋, 浩., Hiroshi A. Takahashi, 秀樹 和田, Hideki Wada, 俊夫 中村, Toshio Nakamura, 英樹 三浦, and Hideki Miura. "<14>^C anatomy of algae in inland ponds and lakes, Antarctica." 名古屋大学年代測定資料研究センター 天然放射性元素測定小委員会, 1999. http://hdl.handle.net/2237/13443.
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Bray, Brandon. "Mafic replenishhment of multiple felsic reservoirs at the Mono domes and Mono Lake islands, California." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123289.
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The Long Valley Volcanic Field is best known for the paroxysmal 0.76 Ma Bishop Tuff caldera-forming eruption. Postcaldera volcanic activity initially was focused within the caldera complex and along its western and southern margins. Starting at ~60 ka, however, intracaldera volcanism ceased and the focus of activity shifted to the north into the Mono Basin. Frequent eruptions over the past 60,000 years have emplaced the Mono domes and the Mono Lake lavas. The Mono Lake lavas, as well as enclaves present in several of the Mono domes, comprise the only material of intermediate composition (andesite, dacite) erupted in the Mono Basin. Recent unrest in Long Valley, combined with the youth of the Mono Basin lavas, underlines the importance of better understanding the petrogenetic processes involved in generating these lavas. To aid in accomplishing this goal, we have undertaken a study of Mono Basin volcanism encompassing whole-rock major and trace element, Sr, Nd, Pb, and O isotopic, and electron microprobe glass, plagioclase, and amphibole analyses. Variations in major and trace elements suggest that fractional crystallization of feldspar (Sr, K2O), apatite (P2O5), titanomagnetite (V), zircon (Zr), and a LREE-bearing phase (La, Ce) has influenced the evolution of the Mono Basin lavas. Field observations, petrography, and chemistry together demonstrate that injection of more mafic magma is a universal process throughout the Mono Basin. Mafic enclaves of the Mono domes are stretched and rounded, with chilled margins between enclave and host rhyolite. Thin sections cut along the enclave-host border show millimeter-scale inclusions of rhyolite in the enclaves and vice versa. Paoha Island dacite has glass with 67-72 wt.% SiO2 and contains microscopic clots of more mafic glasses, with SiO2 contents as low as 64 wt.%. Isotopically, recently erupted regional basalts (e.g., Black Point) and the Mono dome enclaves represent the least radiogenic material in the Long Valley Volcanic Field, with 87Sr/86Sri <0.7056 and 143Nd/144Nd >0.5126. The silicic Mono Lake lavas and Mono dome rhyolites display increasingly crustal signatures, with 87Sr/86Sri >0.7058 and 143Nd/144Nd <0.5127, comparable to the Bishop Tuff. Oxygen and Pb isotopes throughout the sample suite also have crustal signatures, with 206Pb/204Pb >19 and δ18O >+6.5‰. The Mono Lake lavas generally are both younger and less evolved than the Mono domes, with lower 143Nd/144Nd, higher 206Pb/204Pb, and enrichment in trace elements including Ba and Sr. This implies that the Mono domes and the Mono Lake lavas are derived from different batches of magma, if not from separate magma chambers. The lack of any systematic relationship between the degree of chemical evolution and the age of a lava implies that several magma batches have been involved in the development of the Mono domes. Pronounced differences in trace element composition (Nb, Y) and isotopic values between the Negit Island and Paoha Island lavas indicate that they, too, are produced by the evolution of at least two different batches of intermediate-composition magma. Continued unrest in the south moat of Long Valley caldera hints at the potential for future volcanic activity there. Given the recent history of volcanism north of the caldera and the clear evidence presented here for continued mafic recharge beneath the Mono Basin, Mono Lake and the Mono domes are likely candidates for future eruptions.Le champ volcanique de Long Valley est connu pour l'éruption paroxysmale du Bishop Tuff, qui a excavé la caldeira il y a 0.76 Ma. L'activité postcaldeira fut concentrée initialement au sein de la caldeira et le long de ses frontières occidentales et méridionales. À partir de 60 ka, cependant, le volcanisme intracaldeira a cessé et le centre de l'activité s'est dirigé vers le nord, dans le bassin de Mono. Au cours des 60 000 années suivantes, les éruptions fréquentes ont produit les dômes de Mono et les laves du lac Mono. Les laves du lac Mono et les enclaves qui sont présentes dans plusieurs des dômes de Mono constituent le seul matériau de composition intermédiaire (andésitique, dacitique) qui a été éclaté dans le bassin de Mono. L'activité récente à Long Valley, combinée avec la jeunesse des laves du bassin de Mono, met l'accent sur l'importance de mieux comprendre les processus pétrogénétiques qui ont mené à la génération de ces roches. Nous avons entrepris une étude du volcanisme du bassin de Mono qui inclut des analyses des éléments majeurs et traces dans les roches, des analyses isotopiques de Sr, Nd, Pb, et O, et des analyses par microsonde électronique de verres volcaniques, de plagioclases, et d'amphiboles. Les variations en éléments suggèrent que la cristallisation fractionnée de feldspaths (Sr, K2O), d'apatites (P2O5), de titanomagnétites (V), de zircons (Zr), et d'une phase qui affecte les éléments de terres rares légères (La, Ce) a influencé l'évolution des laves. Les observations de terrain, la pétrographie, et la chimie démontrent ainsi que l'injection de magma mafique est un processus important. Les enclaves mafiques sont de formes étirées et arrondies, avec des marges figées entre les enclaves et la rhyolite hôte. Les lames minces de roches qui proviennent du long de la marge entre les enclaves et la rhyolite révèlent des inclusions de rhyolite de taille de l'ordre de quelques millimétres, et vice versa. La dacite de l'île de Paoha contient du verre ayant une composition en silice de 67-72% par masse. Elle contient des gouttes microscopiques de verre plus mafique, avec un contenu en SiO2 aussi bas que 64 pourcent poids. Les basaltes régionaux récentes et les enclaves des dômes de Mono possèdent les valeurs isotopiques les moins radiogéniques de tout le champ volcanique de Long Valley, avec 87Sr/86Sri <0.7056 et 143Nd/144Nd >0.5126. Les laves du lac Mono et les rhyolites des dômes de Mono ont des signatures plus influencées par la croûte terrestre, avec 87Sr/86Sri >0.7058 et 143Nd/144Nd <0.5127. Ces valeurs sont comparables à celles du Bishop Tuff. Les isotopes d'oxygène et de plomb dans la suite possèdent des signatures crustales, avec 206Pb/204Pb >19 et δ18O > +6.5 ‰. Les laves du lac Mono sont généralement plus jeunes et moins évoluées que celles des dômes de Mono, avec des valeurs de 143Nd/144Nd inférieures et de 206Pb/204Pb supérieures à celles des dômes. Elles démontrent aussi un enrichissement en éléments traces comme le Ba et le Sr. Ces observations impliquent que les dômes de Mono et les laves du lac Mono sont issus de lots de magmas différents, sinon de chambres magmatiques distinctes. L'absence de relation systématique entre le niveau d'évolution chimique et l'âge des laves suggère que plusieurs lots de magmas sont impliqués dans le développement des dômes de Mono. Les différences prononcées dans la composition en éléments traces (Nb, Y) et en valeurs isotopiques entre les laves de l'île de Negit et de l'île de Paoha indiquent que celles-ci sont aussi les produits d'une évolution d'au moins deux lots différents de magma de compositions intermédiaires. L'activité volcanique dans la région sud de la caldeira de Long Valley n'écarte pas la possibilité d'activité volcanique future. De plus, le volcanisme récent dans le nord de la caldeira, combiné avec la thèse de la recharge mafique sous le bassin de Mono, suggère que le bassin et les dômes de Mono pourraient connaitre de nouvelles éruptions futures.