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1
Kaseke, Evans. "Fuzzy linear programming and reservoir management." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26708.
Full textAbstract:
The presence of imprecision in parameter specification of water resources
management problems leads to the formulation of fuzzy programming
models. This thesis presents the formulation of a two-reservoir system problem as a fuzzy L.P. model. The aim is to determine if larger monetary
benefits, over and above the usual benefits, can be obtained from the system. The other aim is to determine if desired industrial and domestic water allocations, as well as outflows for selected periods can be achieved.
The problem is formulated as a conventional L.P. model. Then selected water allocations and outflows are fuzzified resulting in a fuzzy L.P. model. The alternative fuzzy L.P. model is also presented.
Monetary benefits larger than those from the conventional L.P. were obtained through the fuzzy L.P. model. The desired water allocations and outflows were also realised for selected periods. Sensitivity information was obtained for fuzzy and non-fuzzy constraints. The alternative fuzzy L.P. model did not give additional valuable information than that obtained from the initial fuzzy L.P. model.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
2
Xie, Ming 1973. "Prediction of daily net inflows for management of reservoir systems." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33043.
Full textAbstract:
Operational planning of water resource systems like reservoirs and hydropower plants calls for real-time forecasting of reservoir inflow. Reservoir daily inflow forecasts provide a warning of impending floods or drought conditions and help to optimize operating policies for reservoir management based on a fine time scale. The aim of this study was to determine the best model for daily reservoir inflow prediction through linear regression, exponential smoothing and artificial neural network (ANN) techniques. The Hedi reservoir, the third largest reservoir in south China with a 1.144 x 109 m 3, was selected as the study site. The performance of these forecasting models, in terms of forecasting accuracy, efficiency of model development and adaptability for future prediction, were compared to one another. All models performed well during the dry season (inflow with low variability), while the non-linear ANNs were superior to other models in frontal rainy season and typhoon season (inflow with high variability). The performance of ANN models were hardly affected by the high degree of uncertainty and variability inherent to the rainy season. Stepwise selection was very helpful in identifying significant variables for regression models and ANNs. This procedure reduced ANN's size and greatly improved forecasting accuracy for ANN models. The impact of training data series, model architecture and network internal parameters on ANNs performances were also addressed in this study. The overall evaluation indicates that ANNs are an effective and robust tool for input-output mapping under more extreme and variable conditions. ANNs provide an alternative forecasting approach to conventional time series forecasting models for daily reservoir inflow prediction.
3
Malik, Kazim A. "An intelligent portfolio management approach to gas storage field deliverability maintenance and enhancement." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4833.
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Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains vii, 105 p. : ill. (some col.) ; map (part col.). Includes abstract. Includes bibliographical references (p. 58-59).
4
Seetha, Ram Katakam V. "Conjunctive And Multipurpose Operation Of Reservoirs Using Genetic Algorithms." Thesis, Indian Institute of Science, 2000. https://etd.iisc.ac.in/handle/2005/222.
Full textAbstract:
Optimal operation of reservoir systems is necessary for better utilizing the limited water resources and to justify the high capital investments associated with reservoir projects. However, finding optimal policies for real-life problems of reservoir systems operation (RSO) is a challenging task as the available analytical methods can not handle the arbitrary functions of the problem and almost all methods employed are numerical or iterative type that are computer dependent. Since the computer resources in terms of memory and CPU time are limited, a limit exists for the size of the problem, in terms of arithmetic and memory involved, that can be handled. This limit is approached quickly as the dimension and the nonlinearity of the problem increases.
In encountering the complex aspects of the problem all the traditionally employed methods have their own drawbacks. Linear programming (LP), though very efficient in dealing with linear functions, can not handle nonlinear functions which is the case mostly in real-life problems. Attempting to approximate nonlinear functions to linear ones results in the problem size growing enormously. Dynamic programming (DP), though suitable for most of the RSO problems, requires exponentially increasing computer resources as the dimension of the problem increases and at present many high dimensional real-life problems can not be solved using DP. Nonlinear programming (NLP) methods are not known to be efficient in RSO problems due to slow rate of convergence and inability to handle stochastic problems. Simulation methods can, practically, explore only a small portion of the search region. Many simplifications in formulations and adoption of approximate methods in literature still fall short in addressing the most critical aspects, namely multidimensionality, stochasticity, and additional complexity in conjunctive operation, of the problem. As the problem complexity increases and the possibility of arriving at the solution recedes, a near optimal solution with the best use of computational resources can be very valuable. In this context, genetic algorithms (GA) can be a promising technique which is believed to have an advantage in terms of efficient use of computer resources.
GA is a random search method which find, in general, near optimal solutions using evolutionary mechanism of natural selection and natural genetics. When a pool of feasible solutions, represented in a coded form, are given fitness according to a objective function and explored by genetic operators for obtaining new pools of solutions, then the ensuing trajectories of solutions come closer and closer to the optimal solution which has the greatest fitness associated with it. GA can be applied to arbitrary functions and is not excessively sensitive to the dimension of the problem. Though in general GA finds only the near optimal solutions trapping in local optima is not a serious problem due to global look and random search.
Since GA is not fully explored for RSO problems two such problems are selected here to study the usefulness and efficiency of GA in obtaining near optimal solutions. One problem is conjunctive operation of a system consisting of a surface reservoir and an aquifer, taken from the literature for which deterministic and stochastic models are solved. Another problem is real-time operation of a multipurpose reservoir, operated for irrigation (primary purpose) and hydropower production, which is in the form of a case study.
The conjunctive operation problem consists of determining optimal policy for a combined system of a surface reservoir and an aquifer. The surface reservoir releases water to an exclusive area for irrigation and to a recharge facility from which it reaches the aquifer in the following period. Another exclusive area is irrigated by water pumped from the aquifer. The objective is to maximize the total benefit from the two irrigated areas. The inflow to the surface reservoir is treated as constant in deterministic model and taken at 6 different classes in stochastic model. The hydrological interactions between aquifer and reservoir are described using a lumped parameter model in which the average aquifer water table is arrived at based on the quantity of water in the aquifer, and local drawdown in pumping well is neglected. In order to evaluate the GA solution both deterministic and stochastic models are solved using DP and stochastic DP (SDP) techniques respectively. In the deterministic model, steady state (SS) cyclic (repetitive) solution is identified in DP as well as in GA. It is shown that the benefit from GA solution converges to as near as 95% of the benefit from exact DP solution at a highly discounted CPU time.
In the stochastic model, the steady state solution obtained with SDP consists of converged first stage decisions, which took a 8-stage horizon, for any combination of components of the system state. The GA solution is obtained after simplifying the model to reduce the number of decision variables. Unlike SDP policy which gives decisions considering the state of the system in terms of storages, at reservoir, aquifer, and recharge facility, and previous inflow at the beginning of that period, GA gives decisions for each period of the horizon considering only the past inflow state of the period. In arriving at these decisions the effect of neglected state information is approximately reflected in the decisions by the process of refinement of the decisions, to conform to feasibility of storages in reservoir and aquifer, carried out in a simplified simulation process. Moreover, the validity of the solution is confirmed by simulating the operation with all possible inflow sequences for which the 8-stages benefit converged up to 90 % of the optimum. However, since 8 stages are required for convergence to SS, a 16-stage process is required for GA method in which the first 8 stages policy is valid. Results show that GA convergence to the optimum is satisfactory, justifying the approximations, with significant savings in CPU time.
For real-time operation of a multipurpose reservoir, a rule curve (RC) based monthly operation is formulated and applied on a real-life problem involving releases for irrigation as well as power production. The RC operation is based on the target storages that have to be maintained, at each season of the year, in the reservoir during normal hydrological conditions. Exceptions to target storages are allowed when the demands have to be met or for conserving water during the periods of high inflows. The reservoir in the case study supplies water to irrigation fields through two canals where a set of turbines each at the canal heads generate hydropower. A third set of turbines operate on the river bed with the water let out downstream from the dam. The problem consists of determining the the RC target storages that facilitate maximum power production while meeting the irrigation demands up to a given reliability level. The RC target storages are considered at three different levels, corresponding to dry, normal, and wet conditions, according to the system state in terms of actual (beginning of period) storage of the reservoir. That is, if the actual beginning storage of the reservoir is less than some coefficient, dry-coe, times the normal target storage the target for the end of the period storage is taken at the dry storage target (of the three sets of storages). Similarly the wet level is taken for the end of the period target if the actual beginning storage is greater than some coefficient, wet-coe, times the normal storage. For other conditions the target is the normal storage level.
The dry-coe and wet-coe parameters are obtained by trial and error analysis working on a small sequence of inflows. The three sets of targets are obtained from optimization over a 1000 year generated inflow sequence. With deterministic DP solutions, for small sequences of inflows, the optimization capability of GA-RC approach, in terms of objective function convergence, and generalization or robustness capability of GA-RC approach, for which the GA-RC benefit is obtained by simulating the reservoir operation using the previously obtained GA-RC solution, are evaluated. In both the cases GA-RC approach proves to be promising. Finally a 15 year real-time simulation of the reservoir is carried out using historical inflows and demands and the comparison with the historical operation shows significant improvement in benefit, i.e. power produced, without compromising irrigation demands throughout the simulation period.
5
Seetha, Ram Katakam V. "Conjunctive And Multipurpose Operation Of Reservoirs Using Genetic Algorithms." Thesis, Indian Institute of Science, 2000. http://hdl.handle.net/2005/222.
Full textAbstract:
Optimal operation of reservoir systems is necessary for better utilizing the limited water resources and to justify the high capital investments associated with reservoir projects. However, finding optimal policies for real-life problems of reservoir systems operation (RSO) is a challenging task as the available analytical methods can not handle the arbitrary functions of the problem and almost all methods employed are numerical or iterative type that are computer dependent. Since the computer resources in terms of memory and CPU time are limited, a limit exists for the size of the problem, in terms of arithmetic and memory involved, that can be handled. This limit is approached quickly as the dimension and the nonlinearity of the problem increases.
In encountering the complex aspects of the problem all the traditionally employed methods have their own drawbacks. Linear programming (LP), though very efficient in dealing with linear functions, can not handle nonlinear functions which is the case mostly in real-life problems. Attempting to approximate nonlinear functions to linear ones results in the problem size growing enormously. Dynamic programming (DP), though suitable for most of the RSO problems, requires exponentially increasing computer resources as the dimension of the problem increases and at present many high dimensional real-life problems can not be solved using DP. Nonlinear programming (NLP) methods are not known to be efficient in RSO problems due to slow rate of convergence and inability to handle stochastic problems. Simulation methods can, practically, explore only a small portion of the search region. Many simplifications in formulations and adoption of approximate methods in literature still fall short in addressing the most critical aspects, namely multidimensionality, stochasticity, and additional complexity in conjunctive operation, of the problem. As the problem complexity increases and the possibility of arriving at the solution recedes, a near optimal solution with the best use of computational resources can be very valuable. In this context, genetic algorithms (GA) can be a promising technique which is believed to have an advantage in terms of efficient use of computer resources.
GA is a random search method which find, in general, near optimal solutions using evolutionary mechanism of natural selection and natural genetics. When a pool of feasible solutions, represented in a coded form, are given fitness according to a objective function and explored by genetic operators for obtaining new pools of solutions, then the ensuing trajectories of solutions come closer and closer to the optimal solution which has the greatest fitness associated with it. GA can be applied to arbitrary functions and is not excessively sensitive to the dimension of the problem. Though in general GA finds only the near optimal solutions trapping in local optima is not a serious problem due to global look and random search.
Since GA is not fully explored for RSO problems two such problems are selected here to study the usefulness and efficiency of GA in obtaining near optimal solutions. One problem is conjunctive operation of a system consisting of a surface reservoir and an aquifer, taken from the literature for which deterministic and stochastic models are solved. Another problem is real-time operation of a multipurpose reservoir, operated for irrigation (primary purpose) and hydropower production, which is in the form of a case study.
The conjunctive operation problem consists of determining optimal policy for a combined system of a surface reservoir and an aquifer. The surface reservoir releases water to an exclusive area for irrigation and to a recharge facility from which it reaches the aquifer in the following period. Another exclusive area is irrigated by water pumped from the aquifer. The objective is to maximize the total benefit from the two irrigated areas. The inflow to the surface reservoir is treated as constant in deterministic model and taken at 6 different classes in stochastic model. The hydrological interactions between aquifer and reservoir are described using a lumped parameter model in which the average aquifer water table is arrived at based on the quantity of water in the aquifer, and local drawdown in pumping well is neglected. In order to evaluate the GA solution both deterministic and stochastic models are solved using DP and stochastic DP (SDP) techniques respectively. In the deterministic model, steady state (SS) cyclic (repetitive) solution is identified in DP as well as in GA. It is shown that the benefit from GA solution converges to as near as 95% of the benefit from exact DP solution at a highly discounted CPU time.
In the stochastic model, the steady state solution obtained with SDP consists of converged first stage decisions, which took a 8-stage horizon, for any combination of components of the system state. The GA solution is obtained after simplifying the model to reduce the number of decision variables. Unlike SDP policy which gives decisions considering the state of the system in terms of storages, at reservoir, aquifer, and recharge facility, and previous inflow at the beginning of that period, GA gives decisions for each period of the horizon considering only the past inflow state of the period. In arriving at these decisions the effect of neglected state information is approximately reflected in the decisions by the process of refinement of the decisions, to conform to feasibility of storages in reservoir and aquifer, carried out in a simplified simulation process. Moreover, the validity of the solution is confirmed by simulating the operation with all possible inflow sequences for which the 8-stages benefit converged up to 90 % of the optimum. However, since 8 stages are required for convergence to SS, a 16-stage process is required for GA method in which the first 8 stages policy is valid. Results show that GA convergence to the optimum is satisfactory, justifying the approximations, with significant savings in CPU time.
For real-time operation of a multipurpose reservoir, a rule curve (RC) based monthly operation is formulated and applied on a real-life problem involving releases for irrigation as well as power production. The RC operation is based on the target storages that have to be maintained, at each season of the year, in the reservoir during normal hydrological conditions. Exceptions to target storages are allowed when the demands have to be met or for conserving water during the periods of high inflows. The reservoir in the case study supplies water to irrigation fields through two canals where a set of turbines each at the canal heads generate hydropower. A third set of turbines operate on the river bed with the water let out downstream from the dam. The problem consists of determining the the RC target storages that facilitate maximum power production while meeting the irrigation demands up to a given reliability level. The RC target storages are considered at three different levels, corresponding to dry, normal, and wet conditions, according to the system state in terms of actual (beginning of period) storage of the reservoir. That is, if the actual beginning storage of the reservoir is less than some coefficient, dry-coe, times the normal target storage the target for the end of the period storage is taken at the dry storage target (of the three sets of storages). Similarly the wet level is taken for the end of the period target if the actual beginning storage is greater than some coefficient, wet-coe, times the normal storage. For other conditions the target is the normal storage level.
The dry-coe and wet-coe parameters are obtained by trial and error analysis working on a small sequence of inflows. The three sets of targets are obtained from optimization over a 1000 year generated inflow sequence. With deterministic DP solutions, for small sequences of inflows, the optimization capability of GA-RC approach, in terms of objective function convergence, and generalization or robustness capability of GA-RC approach, for which the GA-RC benefit is obtained by simulating the reservoir operation using the previously obtained GA-RC solution, are evaluated. In both the cases GA-RC approach proves to be promising. Finally a 15 year real-time simulation of the reservoir is carried out using historical inflows and demands and the comparison with the historical operation shows significant improvement in benefit, i.e. power produced, without compromising irrigation demands throughout the simulation period.
6
Pong, Chung-nam. "Water quality of reservoirs in Hong Kong /." View the Table of Contents & Abstract, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39604238.
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7
Kleopa, Xenia A. "Optimal reservoir operation for drought management." Ohio : Ohio University, 1990. http://www.ohiolink.edu/etd/view.cgi?ohiou1183650664.
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Moore, David L. "Reservoir management during drought an expert system approach." Ohio : Ohio University, 1993. http://www.ohiolink.edu/etd/view.cgi?ohiou1175718241.
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9
Kistenmacher, Martin. "Reservoir system management under uncertainty." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/49012.
Full textAbstract:
Reservoir systems are subject to several uncertainties that are the result of imperfect knowledge about system behavior and inputs. A major source of uncertainty arises from the inability to predict future inflows. Fortunately, it is often possible to generate probabilistic forecasts of inflow volumes in the form of probability density functions or ensembles. These inflow forecasts can be coupled with stochastic management models to determine reservoir release policies and provide stakeholders with meaningful information of upcoming system responses such as reservoir levels, releases, flood damage risks, hydropower production, water supply withdrawals, water quality conditions, navigation opportunities, and environmental flows, among others. This information on anticipated system responses is also expressed in the form of forecasts that must reliably represent the actual system behavior when it eventually occurs. The first part of this study presents an assessment methodology that can be used to determine the consistency of ensemble forecasts through the use of relative frequency histograms and minimum spanning trees (MST). This methodology is then used to assess a management model's ability to produce reliable ensemble forecasts. It was found that neglecting to account for hydrologic state variables and improperly modeling the finite management horizon decrease ensemble consistency. Several extensions to the existing management model are also developed and evaluated. The second portion of this study involves the management of the uncertainties in reservoir systems. Traditional management models only find management policies that optimize the expected values of system benefits or costs, thereby not allowing operators and stakeholders to explicitly explore issues related to uncertainty and risk management. A technique that can be used to derive management policies that produce desired probabilistic distributions of reservoir system outputs reflecting stakeholder preferences is developed. This technique can be embedded in a user-interactive framework that can be employed to evaluate the trade-offs and build consensus in multi-objective and multi-stakeholder systems. The methods developed in this dissertation are illustrated in case studies of real reservoir systems, including a seven-reservoir, multi-objective system in California's Central Valley.
10
龐仲嵐 and Chung-nam Pong. "Water quality of reservoirs in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B45013809.
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Helfer, Fernanda. "Influence of Air-Bubble Plumes and Effects of Climate Change on Reservoir Evaporation." Thesis, Griffith University, 2012. http://hdl.handle.net/10072/365996.
Full textAbstract:
It is estimated that open water reservoirs in Australia lose around 40% of their total water storage capacity per year to evaporation. This can be attributed to the country’s dry climate, with high temperatures and strong winds. To further exacerbate this issue, temperature increases have been recorded during the past decades, and this is predicted to continue over the coming years in Australia. This has been directing even greater concern to how much water will be lost from Australian reservoirs in the future through the evaporation process.
For several decades, Australia has been investigating mechanisms to minimize evaporation from reservoirs. These include the use of physical and chemical covers, windbreaks and even modifying the reservoir shape in order to reduce its surface area. Most of these techniques however, have been shown to be ineffective, as in the example of windbreaks; to be excessively expensive, as in the example of physical covers and modifying the reservoir shape; or to impose potential risks to the water quality, as in the use of chemical covers. Destratification by air-bubble plumes, which involves pumping compressed air into the interior of a reservoir, thereby allowing the resultant bubbles to rise and carry cold bottom water to the surface, is one technique that deserves further investigation. Air-bubble plumes have been suggested in literature as a potential mechanism for reducing evaporation from reservoirs due to their potential effects on water temperature change.
The primary aim of destratification by air-bubble plumes is to maintain or improve the quality of the reservoir water, specifically by increasing dissolved oxygen in the water. The potential of these systems to reduce evaporative losses is related to the change in water temperature attributable to mixing. The intuitive principle is that cold hypolimnetic water is lifted by the air bubbles, and once at the surface, this water mixes with the lighter epilimnetic water, reducing its temperature and consequently, evaporation rates.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
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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.
Full textAbstract:
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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Duvenage, Paul. "Developing a method for prioritising maintenance for reinforced concrete reservoirs." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96671.
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Thesis (MEng)--Stellenbosch University, 2015.ENGLISH ABSTRACT: The Department of Water Affairs and Forestry infrastructure has shown a decline in condition from 2006 to 2011, according to the Infrastructure Report Card. With the increase in population, the additional demand placed on the already ageing infrastructure together with inadequate maintenance exacerbates the deterioration of these structures. Much has been done to improve the provision of basic water services to South Africans, however to ensure that basic water services remain intact, maintenance of the existing structures is of paramount importance. The storage of potable water in a hygienic manner is essential to the water provision network, thus focus is placed on water reservoirs (in particular reinforced concrete water reservoirs). It has been identified that there is a lack of appropriate policies, practices, procedures and guidelines related to the maintenance of municipal water reservoirs. The solution that this study proposes is to develop a maintenance prioritization method for reinforced concrete water reservoirs. This method specifically provides the user (i.e facility manager) with a systematic approach to assessing and allocating a condition value to the reservoir, which is used to prioritize maintenance activities. This method follows the approach used by the TRH/TMH manuals and bridge management systems that are implemented throughout South Africa. This method includes, the breakdown of essential reservoir components thus facilitating the development of future asset registers, the deterioration mechanisms that affect these reservoirs along with the appropriate identification methodologies and the percentage contributions of each component to the overall condition of the facility. The research for the prioritization method is conducted by combining literature with feedback from industry professionals. The literature featured investigation of the components of concrete reservoirs and deterioration mechanisms that affect these components. The results of the feedback from the industry professionals indicated that some of the components contribute more to the overall condition of the facility than others. This contribution is based on the importance of the component with regard to the provision of service and safety. Thus, in the case of a concrete reservoir, the walls are more essential to the provision of service and safety than the access components, thus its contribution percentage is higher. The research suggests that if the prioritization method could successfully be implemented, it will provide the users additional information that can be used to prioritise maintenance activities at both component and network level. Further, it may allow for the development of a comprehensive asset register of concrete reservoirs and may also aid in the financial planning related to the maintenance of these structures.
AFRIKAANSE OPSOMMING: Die Departement van Waterwese en Bosbou se infrastruktuur het n afname in kondisie gradering getoon van 2006 tot 2011 volgens die Infrastruktuur Verslag Kaart. Die toename in die bevolking veroorsaak bykomende druk op die reeds verouderende infrastruktuur wat tesame met swak instandhouding die agteruitgang van hierdie strukture vererger. Baie is gedoen om die voorsiening van basiese waterdienste aan Suid-Afrikaners te verbeter, maar dit is uiters noodsaaklik dat bestaande strukture in stand gehou word om te verseker dat basiese waterdienste beskikbaar bly. Die berging van drinkwater op ’n higiëniese wyse is noodsaaklik vir die watervoorsieningsnetwerk met die gevolg dat daar op waterreservoirs, spesifiek gewapende beton waterreservoirs, gefokus word. Daar is vasgestel dat daar nie toepaslike praktyke, prosedures en riglyne met betrekking tot die instandhouding van van munisipale waterreservoirs bestaan nie. Die oplossing wat deur hierdie studie voorgestel word, is om ’n onderhoud prioritisering metode vir gewapende beton waterreservoirs te ontwikkel. Hierdie metode bied spesifiek aan die gebruiker (reservoir bestuurder) ’n sistematiese benadering om ’n toestandwaarde ten opsigte van die reservoir te bepaal en toe te wys, wat gebruik word om instandhoudingsaktiwiteite te prioritiseer. Hierdie metode volg die benadering van die TRH/TMH en brug bestuur sisteme, wat geimplimenteer word reg deur Suid Afrika. Hierdie metode sluit in die klassifiseering van hoof komponente van ’n gewapende beton reservoir wat die ontwikkeling van toekomstige bateregisters, die degenerasiemeganismes wat hierdie reservoirs beïnvloed tesame met die gepaste identifiseringsmeganismes en die bydrae volgens persentasie van elke komponent tot die algehele toestand van die fasiliteit, fasiliteer. Die navorsing ten opsigte van die prioritiserings metode is uitgevoer deur literatuur met terugvoer van bedryfskundiges te kombineer. Die literatuur wat geraadpleeg is handel oor die ondersoek na die komponente van gewapende beton reservoirs en degenerasiemeganismes wat hierdie komponente beïnvloed. Die studie dui aan dat, aan die hand van die bedryfskundiges se terugvoer, sommige komponente meer as ander tot die algehele toestand van die fasiliteit bydra. Hierdie bydrae is gebaseer op die belangrikheid van die komponent in terme van die voorsiening van dien ek veiligheid. Dus, is die geval van n beton reservoir, is die mure meer van beland as die toegans komponente in terme van voorsiening van diens en veiligheid. Die navorsing gee te kenne dat indien die prioritiserings metode suksesvol geïmplementeer kan word, dit die gebruiker bykomende inligting kan gee wat gebruik kan word om die instandhoudingsaktiviteite te prioritiseer op beide netwerk en komponente vlak. Verder, mag daar ’n omvattende bateregister van gewapende beton reservoirs ontwikkel kan word wat dus sal help met die finansiële beplanning rondom die instandhouding van hierdie strukture.
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Ruhl, Nathan A. "The Lotic-Lentic Gradient in Reservoirs and Estuaries." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1339177201.
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Peterson, Nick Ryan. "Subspecies composition, genetic variation and structure of Largemouth Bass in Puerto Rico reservoirs." Thesis, Mississippi State University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1604215.
Full textAbstract:
Subspecies composition and genetic variation are important to the growth and survival of Largemouth Bass and information on these genetic characteristics is required for proper management of the species. In Puerto Rico, a genetic evaluation is needed to develop management plans for Puerto Rico reservoirs and maintain Florida Largemouth Bass at the Maricao Hatchery. Subspecies composition was characterized among reservoirs and the contemporary Maricao Hatchery broodstock in Puerto Rico, and metrics were compared between subspecies and hybrids among reservoir populations. Genetic variation and structure was determined and compared to Largemouth Bass populations in their native range. Florida subspecies were prevalent in all populations and non-introgressed subspecies seemed to be better adapted to the island than introgressed forms. Genetic diversity was lower in Puerto Rico populations and substantial genetic structure among populations was lacking. These results provide genetic information to guide future management and propagation of Largemouth Bass in Puerto Rico.
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García, Iturbe Selma L. "Simulation of physical and chemical processes in reservoirs: Two case studies." Thesis, University of North Texas, 2005. https://digital.library.unt.edu/ark:/67531/metadc4968/.
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Managing water quality aspects requires the use of integrative tools that allow a holistic approach to this problem. Water quality models coupled to hydrodynamic models are these tools. This study presents the application of the water quality model WASP coupled to the hydrodynamic model DYNHYD for two distinct reservoirs: Lake Texoma and Tocoma Reservoir. Modeling the former included simulations of water velocities, water level, and four chemical and physical compounds: chlorides, dissolved oxygen (DO), biochemical oxygen demand (BOD), and total suspended solids (TSS); and validation of the results by comparing with observed values during March - May, 1997. The latter is still under project status and the simulation was performed in a prospective way. The analysis included simulations of water velocities under current and for expected conditions, DO and BOD. Both models, DYNHYD and WASP, fitted pretty well to observed conditions for Lake Texoma and for where Tocoma Reservoir has been planned. Considering management and decision support purposes, the role of boundary and loading conditions also was tested. For Lake Texoma, controlling boundary conditions for chlorides is a determinant factor for water quality of the system. However, DO and TSS in the reservoir are governed by additional process besides the condition of the boundary. Estimated loadings for this system did not provided significant effects, even though the allocation of a load for chlorides resulted in significant changes in the trend for expected chloride concentrations at the Washita River Arm of Lake Texoma. For Tocoma Reservoir, the expected concentration of DO all over the reservoir is going to driven by boundary conditions, as well as by the management of autochthonous BOD loadings provided by vegetation decomposition. These two factors will be determinant for the resulting water quality of the future reservoir.
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Bertone, Edoardo. "Decision Support System for Manganese Forecasting and Proactive Treatment in Subtropical Water Reservoirs." Thesis, Griffith University, 2015. http://hdl.handle.net/10072/366512.
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Water utilities around the world have adopted raw water treatment procedures in order to deliver to consumers the water that meets the drinking water quality standards set by national or international regulations. The raw water not only must be purified from harmful constituents that can cause waterborne diseases, but aesthetical standards must also be maintained to avoid customer complaints, which would reduce the confidence of the community towards the drinking water supplier. Potable water having a high concentration of manganese is one of the most widespread aesthetic issues reported by customers. Manganese in reservoirs is a trace metal typically present in small amounts. However, concentrations as small as 0.1 mg/L can cause water discoloration, staining, and even metallic taste. Many international drinking water standards set the upper acceptance limit to 0.05 mg/L for water delivered to the consumers; yet many water utilities such as Seqwater, in South East Queensland, Australia, usually target concentrations of manganese dissolved in the treated water lower than 0.02 mg/L, in order to avoid potential adverse customer reactions to discoloured water. The manganese removal procedure usually is limited to pre-filter chlorination, but for very high manganese levels, the addition of potassium permanganate is performed, because of the faster oxidation reaction.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Corrado, Kristi C. "An Analysis of the Corriental Reservoir Sediments in Relation to Ancient Maya Land Management and Sustainability Practices at Tikal, Guatemala." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1396454782.
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Scott, Robert Nigel. "Algal and related biological studies of reservoirs in South Wales with reference to management of water treatment systems." Thesis, Cardiff University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238187.
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Taymaz, Esmaeili. "THREE-DIMENSIONAL NUMERICAL STUDY ON FREE-FLOW FLUSHING FOR ENHANCING THE EFFICIENCY OF SEDIMENT MANAGEMENT IN RESERVOIRS." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/202697.
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Akpinar, Ezgi. "Aguadas: A Significant Aspect of the Southern Maya Lowlands Water Management Systems." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307320694.
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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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Mulhearn, David Thomas. "Community collaboration and restriction of use for the control of invasive threats in multipurpose reservoirs." Restricted access (UM), 2007. http://libraries.maine.edu/gateway/oroauth.asp?file=orono/etheses/37803141.pdf.
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Brown, Krista M. "GROUNDWATER-STREAM INTERACTIONS AND WATER QUALITY OF FORMER DAM RESERVOIRS IN NORTHEAST, OHIO." Kent State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=kent1564530847224908.
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Brown, Allan W. "The use of selected Scottish Reservoirs by waterfowl : the role of monitoring in site designation, conservation and management." Thesis, University of Dundee, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521702.
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Fernholz, Savannah. "Relative Densities, Population Characteristics, and Sampling Efficiency of Bighead and Silver Carp in Reservoirs of the Tennessee River and Cumberland River." Thesis, Tennessee Technological University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10979492.
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Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix (collectively referred to as bigheaded carp) were introduced to the United States in the 1970s and escaped into the Mississippi River from aquaculture ponds. Since their escape, bigheaded carp have become established in the Mississippi River Basin, including the Ohio River and its tributaries. More recently, bigheaded carp have invaded the Tennessee and Cumberland rivers. Little research has been conducted on bigheaded carp in Tennessee waters, with preliminary studies investigating the distribution and characteristics of established bigheaded carp populations, including growth rates and recruitment. My study represents the first systematic sampling of bigheaded carp in the Tennessee and Cumberland rivers, both tributaries to the Ohio River, and in large reservoirs in the southeast U. S. Standardized, multi-gear sampling methods were used to sample bigheaded carp in Kentucky Lake and Pickwick Lake on the Tennessee River and Lake Barkley and Cheatham Lake on the Cumberland River in 2017 and 2018. Overnight gill nets were the most effective gear, capturing an average of 17 Silver Carp per gill net gang. Short-set gill nets captured an average of one Silver Carp per gill net gang, and electrofishing captured an average of one Silver Carp per 10-minute electrofishing transect. Maximum total length (TL) was 1,390 mm for Bighead Carp and 1,111 mm for Silver Carp, and the maximum age for both species was 11 years. Average age and condition of Silver Carp was higher in upstream impoundments than downstream, and thus suggested an early invasion period from Ohio River movements. Gonadosomatic index (GSI; egg mass weight to body weight ratio) was also higher in upstream impoundments than downstream impoundments. Higher GSI values were observed in the spring and summer, when bigheaded carp may begin to spawn in response to high flows. Length-at-age estimates for the four reservoirs suggested bigheaded carp growth rates in the Tennessee and Cumberland rivers are similar to other populations in the US, indicating populations may be experiencing density effects in southeastern impoundments. No young of year (YOY) bigheaded carp were captured during the study, but weak and missing year classes due to erratic recruitment patterns are common in bigheaded carp, and monitoring for YOY fish should continue. Mean catch-per-unit-effort (CPUE) was not significantly different among reservoirs for the three gear types, and no significant seasonal variation in mean CPUE was observed for overnight gill nets. A lack of differences in CPUE across sampling seasons suggested population densities could be assessed as agencies could fit into their schedules. Overall, the results represent the first large-scale standardized sampling effort for bigheaded carp across four southeastern states and provide integral population information for natural resource managers. Future monitoring efforts should continue to track characteristics of bigheaded carp populations in the Tennessee and Cumberland rivers and determine effective control and management strategies for populations in large impoundments.
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Haynie, Rebecca S. "Investigating risks, effects, and a potential management strategy for avian vacuolar myelinopathy on Southeastern reservoirs using an eco-epidemiological approach." Connect to this title online, 2008. http://etd.lib.clemson.edu/documents/1211389032/.
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Salami, Yunus. "Risk Management in Reservoir Operations in the Context of Undefined Competitive Consumption." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5478.
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Dams and reservoirs with multiple purposes require effective management to fully realize their purposes and maximize efficiency. For instance, a reservoir intended mainly for the purposes of flood control and hydropower generation may result in a system with primary objectives that conflict with each other. This is because higher hydraulic heads are required to achieve the hydropower generation objective while relatively lower reservoir levels are required to fulfill flood control objectives. Protracted imbalances between these two could increase the susceptibility of the system to risks of water shortage or flood, depending on inflow volumes and operational policy effectiveness. The magnitudes of these risks can become even more pronounced when upstream use of the river is unregulated and uncoordinated so that upstream consumptions and releases are arbitrary. As a result, safe operational practices and risk management alternatives must be structured after an improved understanding of historical and anticipated inflows, actual and speculative upstream uses, and the overall hydrology of catchments upstream of the reservoir. One of such systems with an almost yearly occurrence of floods and shortages due to both natural and anthropogenic factors is the dual reservoir system of Kainji and Jebba in Nigeria. To analyze and manage these risks, a methodology that combines a stochastic and deterministic approach was employed. Using methods outlined by Box and Jenkins (1976), autoregressive integrated moving average (ARIMA) models were developed for forecasting Niger river inflows at Kainji reservoir based on twenty-seven-year-long historical inflow data (1970-1996). These were then validated using seven-year inflow records (1997-2003). The model with the best correlation was a seasonal multiplicative ARIMA (2,1,1)x(2,1,2)12 model. Supplementary validation of this model was done with discharge rating curves developed for the inlet of the reservoir using in situ inflows and satellite altimetry data. By comparing net inflow volumes with storage deficit, flood and shortage risk factors at the reservoir were determined based on (a) actual inflows, (b) forecasted inflows (up to 2015), and (c) simulated scenarios depicting undefined competitive upstream consumption. Calculated high-risk years matched actual flood years again suggesting the reliability of the model. Monte Carlo simulations were then used to prescribe safe outflows and storage allocations in order to reduce futuristic risk factors. The theoretical safety levels achieved indicated risk factors below threshold values and showed that this methodology is a powerful tool for estimating and managing flood and shortage risks in reservoirs with undefined competitive upstream consumption.Ph.D.
Doctorate
Civil, Environmental, and Construction Engineering
Engineering and Computer Science
Civil Engineering
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Brown, Forrest C. "The fish population of an east-central Indiana borrow pit lake with management implications." Virtual Press, 1985. http://liblink.bsu.edu/uhtbin/catkey/412514.
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The fish, invertebrate, and macrophyte communities of Dumpert's Lake, a borrow pit located in northwest Delaware County, Indiana were studied in 1979 and 1980. Data obtained from this study were used to evaluate the potential for quality fishing, to identify sport fish production problems, to assess largemouth bass food habits and habitat utilization, and to consider management options.Bluegill dominated the July and September, 1980 fish collections at 69 and 84 percent, respectively. The growth rates for age II and older bluegill indicated mortality rates above 55 percent. Stocklength (3 in., 76 mm) was.attained at annulus 2 and quality-length (6 in., 152 mm) was reached at age III+. The overall average annual growth increment was 48 mm (1.9 in.). Bluegill were in good condition by overall average K at capture (2.05) and at annulus formation (1.91). Corresponding mean Relative Weight (Wr) values were 106 and 107, respectively.Largemouth bass comprised 23 and 14 percent, respectively, of the July and September, 1980 fish collections. Bass attained stock-length (8 in., 200 mm) by age II+ and an additional 1.5-2.0 years (age III+ or older) was required to attain quality-length (12 in., 300 mm). Growth rates and length-frequency distribution verified mortality rates in excess of 60 percent for all age groups of stock-size bass. Average yearly growth was 70 mm (2.8 in.). Condition was poor by overall average K at capture (1.27) and at annulus formation (1.22). The overall mean Wr was 89 for the respective K values.A stock structure index, Proportional Stock Density (PSD), indicated an unbalanced largemouth bass and bluegill population. Bluegill PSD was 78 with largemouth bass PSD at 27.Radio telemetry observations for two largemouth bass monitored from late May to mid-July, 1980 indicated relative inactivity by observed displacement (98 and 366 m) with respective home ranges of 0.01 and 0.12 ha. Extensive use of shoreline cattails was noted at 79 and 84 percent of the respective locations. All observations were over lake depths of 0.5-0.9 m. Two bass tracked from late July to mid-September, 1980 were more active by displacement (1401 and 1429 m) with home ranges of 0.92 ha for both fish, and similar utilization of submergent pondweeds (46 and 50 percent, respectively). One bass was always observed over lake depths of 1.0 m or greater. The other bass was observed in shallow water (0.5-0.9 m) for 50 percent of the observations.Fish occurred more frequently (71 percent) in stomachs of largemouth bass ranging from 195-247 mm than in stomachs (11 percent) of bass 253-347 mm total length. Insects dominated the diet of the larger fish by percent in volume and weight (66 percent) compared to the smaller stock-size bass (21-22 percent). Odonata was the most frequent insect taxa in the diet of the smaller bass at 29 percent and Ephemeroptera was the dominant insect taxa (33 percent) in the diet of the larger fish.Epifaunal macroinvertebrates were more diverse by taxa compared to macroinvertebrates from three benthic habitats which were about equal in diversity by taxa. Zooplankton diversity by taxa was also similar among the benthic habitats. Macroinvertebrate density showed a trend of seasonal increase for the 1979 summer period, while distinct biomodal peaks for zooplankton abundance occurred in early July and late August, 1979 for vegetated and nonvegetated littoral zones.Najas flexilis, Potamogeton nodosus, and P. pusillus dominated the submergent macrophyte community in 1979. The overall mean seasonal dry weight biomass of macrophytes was 110 g/m2 (114 g/m3 ). Macrophyte control was recommended for improving the sport fishery.Ball State UniversityMuncie, IN 47306
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Choodegowda, Ravikumar B. "Modeling small reservoirs in the Great Plains to estimate overflow and ground-water recharge." Diss., Kansas State University, 2009. http://hdl.handle.net/2097/4610.
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Doctor of PhilosophyDepartment of Biological & Agricultural Engineering
James K. Koelliker
Small reservoirs catch and store water for long periods and they decrease streamflow and increase ground-water recharge. A field monitoring program provided the measured water depth for four years in several reservoirs in the Republican River Basin where there are concerns about their aggregate effects in the basin. The daily water budget operation for one reservoir was developed. Daily seepage rates were estimated by using precipitation, inflow and evaporation which was assumed equal to grass reference evapotranspiration (ET0), that average 120 to 150 cm/yr, along with the measured stage-storage and stage-surface area relationships. Two computer simulation modules, written in FORTRAN 95, were developed to estimate 1) overflow and gross seepage and 2) potential for ground-water recharge underneath the reservoir. Required daily input data are precipitation, ET0, and inflow from the watershed area. Required reservoir site characteristics include stage-storage and stage-surface area relationships, a standard seepage rate (S0) at 14 different levels in the reservoir, soil-water and plant-growth characteristics and a monthly crop-residue factor. The gross seepage module calculates water depth that determines daily overflow, the water-surface area for evaporation and the head of water on the 14 levels to cause seepage losses. If a level is not inundated, seepage is zero. If a level is inundated less than 0.3-m, S0 is used. When the water head (hL) on a level exceeds 0.3 m, the seepage rate (SL) is increased by, SL = S0 * (hL/0.3)0.25. This relationship was chosen after testing several exponent values between 0 and 1. The modules were calibrated on one reservoir and verified on two others in northwestern Kansas. Results showed runoff from the watersheds averaged about 1.2 to 1.6 cm/yr from the average annual precipitation of 46 to 62 cm. The three reservoirs reduced streamflow at the reservoir site by 74 to 97%, but 90 to 95% of the retained runoff was calculated to contribute to ground-water recharge. Several sensitivity analyses for model inputs were done. Results showed that, the ratio of the average annual inflow volume from the watershed area to the reservoir storage volume was the most sensitive input variable tested.
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Crouch, Ryan T. "Adding value to upground drinking water reservoirs: what makes a good yellow perch (Perca flavescens) fishery?" Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1291841439.
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Maia, James Lacerda. "Técnicas para o gerenciamento quanti-qualitativo de reservatórios com usos múltiplos da água: estudo de caso do reservatório de Barra Bonita - SP." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-13102009-101327/.
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Os aspectos quantitativos regem as práticas de engenharia visando o gerenciamento de reservatórios. Entretanto, a preocupação em relação aos aspectos qualitativos da água tem aumentado, já que um número cada vez maior de reservatórios estão sendo utilizados para vários tipos de usos. No processo de gerenciamento de reservatórios é necessário que se leve em consideração todos os usos que serão beneficiados pelo sistema em questão. Nesse sentido, o objetivo do trabalho foi o emprego de técnicas computacionais para análise quanti-qualitativa dos usos múltiplos do reservatório de Barra Bonita - SP, realizando simulações computacionais através do modelo MIKE BASIN; propondo e testando um modelo de otimização com programação não-linear baseado no método das restrições e incorporando o uso de geotecnologias para análise espacial (distribuição horizontal) e temporal (sazonalidade) da qualidade da água do reservatório. Selecionou-se o reservatório de Barra Bonita para análise, devido aos usos múltiplos da água (geração de energia, navegação, recreação, turismo e pesca) e a presença de uma eclusa para transposição do desnível entre a jusante da barragem e o reservatório de acumulação da hidrelétrica, o que torna o reservatório uma área de estudo diferenciada. Os resultados das simulações realizadas no modelo MIKE BASIN para avaliar os usos múltiplos do reservatório, demonstraram que o melhor cenário foi o que estabeleceu prioridades iguais para a geração de energia e a navegação. A maximização da geração de energia hidroelétrica, através do modelo de otimização, não prejudicou os outros usos do reservatório (principalmente a navegação) e, mesmo no período seco, a energia média gerada pelo modelo registrou valores acima da energia média real gerada pela Usina Hidrelétrica de Barra Bonita-SP (período de 2001 a 2005). O emprego de geotecnologias (software Surfer) proporcionou boas condições para análise espaço-temporal da qualidade da água, quando aliado ao conhecimento sobre as características e condições do ambiente de estudo. Os dados obtidos em campo, demonstraram que algumas variáveis analisadas, como a condutividade elétrica e a turbidez aumentam significativamente do período seco para o chuvoso, pois estão diretamente relacionados com o aporte de material orgânico e inorgânico. O potencial hidrogeniônico (pH) sofre uma variação muito pequena do período seco para o chuvoso, mas seus valores variam espacialmente, sendo encontrados valores maiores no compartimento da barragem para o período seco, e no final do braço do rio Piracicaba para o período chuvoso. Quanto ao oxigênio dissolvido, este aumenta bastante do período chuvoso para o seco, mas em ambos os períodos as maiores concentrações são encontradas no final do braço do rio Piracicaba - SP. Ressalta-se, que apenas o oxigênio dissolvido (estação seca) não se enquadrou no padrão da Resolução CONAMA nº 357/2005, para águas de classe II.The quantitative aspects rule the engineering practices aimed at reservoirs management. However, the concern about the qualitative aspects of water has increased, since a growing number of reservoirs are being used for many kinds of applications. In the process of reservoir management it is necessary to take into consideration all the uses that will benefit from the system itself. Hence, the objective of this study was the use of computational techniques for quantitative and qualitative analysis of the multiple applications of the reservoir of Barra Bonita - SP, performing computer simulations using the model MIKE BASIN, proposing and testing an optimization model with non-linear programming based on the constraint method and incorporating the use of geotechnologies for spatial (horizontal distribution) and time (seasonal distribution) analysis of the reservoir water quality. It was selected the reservoir of Barra Bonita for analysis because of the multiple applications of the water (power generation, navigation, recreation, tourism and fishing) and the presence of a lock for transposition of the gap between the dam downstream and the power plant accumulation reservoir, which makes the reservoir a different area of study. The results of the simulations performed in MIKE BASIN model to evaluate the multiple applications of the reservoir showed that the best scenario was the one in which the priorities were the same for power generation and navigation. The maximization of the hydropower generation through the optimization model, did not impair other uses of the reservoir (mainly navigation) and even in the dry season, the average power generated by the model registered values above the average real power generated by the Hydroelectric Power Plant of Barra Bonita-SP (from 2001 to 2005). The use of geotechnologies (Surfer software) provided good conditions for space-time analysis of water quality when coupled with the knowledge about the characteristics and conditions of the studied environment. The data obtained showed that some variables, such as electrical conductivity and turbidity significantly increase from the dry season to the rainy season, since they are directly related to the supply of organic and inorganic materials. The hydrogen potential (pH) undergoes a very small variation from the dry season to the rainy season, but its values vary spatially, with higher values found in the compartment of the dam during the dry season, and at the end of the arm of the Piracicaba river during the wet season. The dissolved oxygen greatly increases from the rainy season to the dry one, but in both periods the highest concentrations are found at the end of the arm of the river Piracicaba - SP. It is emphasized that only the dissolved oxygen (dry season) did not fit the pattern of CONAMA Resolution nº 357/2005, to class II waters.
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Weber, Michael [Verfasser], Bertram [Akademischer Betreuer] Boehrer, and Andreas [Gutachter] Lorke. "Optimizing withdrawal from drinking water reservoirs to combine downstream river demands with a sustainable raw water management / Michael Weber ; Gutachter: Andreas Lorke ; Betreuer: Bertram Boehrer." Landau : Universität Koblenz-Landau, Campus Landau, 2018. http://d-nb.info/1161409882/34.
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Brogan, Connor O'Beirne. "A Dam Conundrum: The Role of Impoundments in Stream Flow Alteration." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/85005.
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Over the past century, the world's rivers have become increasingly impounded to combat water scarcity and fossil-fuel reliance. Large dams have faded from popularity due to their adverse environmental effects, but small ponds and reservoirs continue to be constructed at high rates. Due to limited data regarding their size and flow, it has been difficult to assess how these smaller impoundments impact rivers. This study combined rainfall runoff data from the Chesapeake Bay Model with the unique routing framework of VA Hydro to create a simplistic hydrologic model capable of analyzing impoundment-induced flow alteration. Using standard design techniques and satellite imagery, a methodology was developed to build realistic stage-storage-discharge relationships for small and large impoundments. Eleven impoundments of the Difficult Run watershed were modeled within VA Hydro to assess their cumulative impact on downstream flow. Multiple models were created with different active impoundments and run for the full model period, 1984 - 2005. Flow alteration increased significantly with additional impoundments. Peak flows were attenuated as water was stored behind outlets, but median flows were increased as this water was slowly released. Average storm duration increased due to extended rising and falling limbs caused by impoundment outlets. Headwater channels increasingly ran dry, decreasing extreme low flows due to impoundment evaporation. Large reservoirs had a greater impact on median flows, but smaller ponds dominated low flow alteration. These results suggest that traditional hydrologic assumptions and metrics may be incapable of analyzing a changing flow regime without explicitly considering small and large impoundments upstream.Master of Science
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OCK, Giyoung. "PARTICULATE ORGANIC MATTER DYNAMICS IN THE DOWNSTREAM OF DAM RESERVOIRS: ROLES OF CHANNEL GEOMORPHOLOGY AND RESPONSES OF BENTHOS COMMUNITIES." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120804.
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Sequeira, Erik Augusto da Cruz. "Gestão do perímetro de rega da Barragem de Banca Furada: uma proposta." Master's thesis, ISA/UL, 2015. http://hdl.handle.net/10400.5/11112.
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Mestrado em Engenharia Agronómica - Ramo de Engenharia Rural - Instituto Superior de AgronomiaThe São Nicolau Island has recently benefited from its first dam, the Banca Furada. In a region where water availability is limited and it is critical to manage this resource. This work aims to draw up a proposal for improving irrigation management for the irrigation area of the Banca Furada dam. To prepare this paper was performed a socio-economic survey to farmers who will benefit on the irrigation perimeter Were selected 12 crops within the most commonly used by farmers in the area and raised three rainfall scenarios. The irrigation crops consumption was achieved in the three scenarios and then proceeded to the simulation of reservoir operation for the same scenarios with "Simula" programme in VBA (Visual Basic) developed by Pro- Sistemas. As result it was found, that the irrigation areas cannot depass 36 ha, 41 ha and 55 ha, for scenarios 1, 2 and 3 respectively. Crops showed a gross margin exceeding 1,000 euros. The water consumption of crops does not differ much between scenarios, with two water consumption peaks on the perimeter, from November to February and from March to June.
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Lambert, Sébastien. "Transmission and management of brucellosis in a heterogeneous wild population of Alpine ibex (Capra ibex)." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1278.
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La gestion des maladies infectieuses dans la faune sauvage se heurte à de nombreuses limites, et le développement de stratégies efficaces représente un défi de taille. Pour atteindre cet objectif, une compréhension fine des facteurs influençant la transmission et la persistance de l’infection est nécessaire. Parmi ces facteurs, l’hétérogénéité de transmission est une caractéristique importante des populations sauvages. En effet, la diversité des comportements, des structures sociales et spatiales, ou encore des espèces peut conduire à des contributions très variables au nombre de nouvelles infections. Par conséquent, quantifier l’hétérogénéité de transmission pourrait permettre d’améliorer l’efficacité des mesures de gestion sanitaire dans la faune sauvage, en ciblant les individus ou les unités de population qui sont responsables de la majorité des évènements de transmission. L’objectif de cette thèse était d’améliorer les connaissances sur la gestion des maladies infectieuses dans des populations sauvages hétérogènes, en utilisant la brucellose à Brucella melitensis dans une population de bouquetin des Alpes (Capra ibex) comme modèle d’étude. En effet, la biologie de la brucellose et l’écologie de l’espèce hôte se prêtent bien à l’existence et donc à l’étude d’une hétérogénéité de transmission à différentes échelles. A l’aide de cultures bactériennes, nous avons tout d’abord montré que seulement 58 % des individus séropositifs sont à risque d’excréter la brucellose, et que ce risque diminue avec l’âge. Ensuite, mettant à profit l’existence d’informations détaillées sur la dynamique de population et le comportement du bouquetin, et de données épidémiologiques dans la population d’étude, nous avons développé un modèle individu-centré afin de quantifier l’hétérogénéité individuelle et spatiale de la transmission. Nous avons démontré que la transmission de la brucellose était hétérogène entre individus, les femelles provoquant environ 90% des nouvelles infections, et entre unités spatiales, plus de 80% des cas de transmission ayant lieu dans les trois sous-unités socio-spatiales qui forment la zone cœur du massif. Nous avons également estimé l’évolution temporelle de la séroprévalence et de la force d’infection, en utilisant différents modèles statistiques. Les résultats suggèrent que l’importante opération de capture menée en 2015, avec test systématique et élimination des individus séropositifs, a permis de diminuer la transmission de la brucellose dans la population. Sur la base de l’ensemble de ces résultats, nous avons évalués une série de stratégies de gestion sanitaire qui pourraient être utilisées à l’avenir dans la population. Les résultats, issus du modèle individu-centré, confirment que la stratégie prioritaire devrait être d’éliminer le plus d’individus séropositifs, et que cibler les femelles et/ou la zone cœur permet d’améliorer l’efficacité des mesures. Bien qu’il n’y ait pas de solution évidente pour la gestion de la brucellose dans notre cas d’étude, les stratégies de gestion ciblées sont très prometteuses et permettent de raffiner les mesures sanitaires classiquement utilisées. Il est donc primordial de bien comprendre l’hétérogénéité de transmission dans les populations sauvages infectées, et de rechercher des stratégies ciblées qui peuvent permettre d’améliorer la gestion en termes d’efficacité et d’acceptabilitéThe management of infectious diseases in wildlife reservoirs is particularly challenging and faces several limitations. The development of appropriate management strategies requires a detailed understanding of the factors affecting the transmission and persistence of the infectious agent in the population. Among these factors, heterogeneity of transmission is a common characteristic in natural host-pathogen systems. Indeed, wild animals express a broad range of behaviours, are organised in a variety of social and spatial structures, occupy many areas with very different characteristics and belong to a large diversity of species. Such heterogeneities, from between-individuals to between-species, may result in different contributions to the overall number of new cases of infections. Thus, understanding transmission heterogeneity could provide valuable insights on how to effectively manage these systems, by targeting the individuals or areas that are responsible for most transmissions. The aim of this thesis was to provide insights on the monitoring and management of infectious diseases in heterogeneous wild populations, using Brucella melitensis infection in a French population of wild Alpine ibex (Capra ibex) as a case study. The biology of brucellosis and the ecology of Alpine ibex makes this case study a good candidate for transmission heterogeneity at several levels. Using bacterial examinations, we first established that only 58% of seropositive individuals were at risk to excrete Brucella, and that this risk decreased with increasing age. Then, we took advantage of detailed information available on ibex population dynamics, behaviour, and habitat use, and on epidemiological surveys, to build an individual-based model in order to quantify heterogeneity at the individual and spatial levels. The transmission is extremely heterogeneous between individuals, with females generating around 90% of the new cases of brucellosis infection, and between spatial units, three of the five socio-spatial units (the core area) accounting for more than 80% of brucellosis transmission. Using statistical models to estimate the temporal dynamics of the seroprevalence and of the force of infection in the population, we found evidence that the massive captures with test-and-remove operations that were conducted in 2015 managed to reduce brucellosis transmission in the population. Based on these results, we evaluated several predictive disease management strategies in the individual-based model. Our results confirmed that the primary strategy should be to remove as many seropositive individuals as possible, and that strategies targeting females and/or the core area are more effective than untargeted management. Although there is no silver bullet for the management of brucellosis in the population of study, targeted strategies offer a wide range of promising refinements to classical sanitary measures. We therefore encourage to look for heterogeneity in other infection-wildlife systems and to evaluate potential targeted strategies for improving management schemes in terms of efficiency and acceptability
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Mendes, Ludmilson Abritta. "O impacto dos usos consuntivos na operação de sistemas de reservatórios para produção de energia elétrica." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-10052013-213408/.
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Este trabalho trata da avaliação dos impactos que os múltiplos usos da água causam à operação dos reservatórios de uma bacia hidrográfica para a geração de energia elétrica. Apresenta-se o equacionamento do modelo HIDRO, desenvolvido em linguagem GAMS para tratamento de problemas de otimização em Programação Não Linear, cuja função objetivo inclui variáveis relacionadas não somente à geração de energia, como também ao fornecimento de água aos diversos usos do recurso hídrico tratados no problema. A aplicação do modelo é feita para a bacia do rio São Francisco, localizada entre as regiões Sudeste e Nordeste do Brasil, que conta com uma capacidade instalada de 10,7 GW em suas usinas hidrelétricas, as quais também realizam operações de controle de cheia. A região apresenta um expressivo uso consuntivo do recurso hídrico, principalmente voltado à irrigação de culturas, além de abastecimento humano e criação animal. Dentre os usos não consuntivos, têm-se a navegação e a conservação ambiental. Uma vez que grande parte da bacia é marcada por escassez hídrica, a operação de seu sistema de reservatórios vem sendo questionada no que se refere ao gerenciamento dos recursos hídricos. São avaliados os índices de atendimento da demanda de energia e da demanda hídrica para cenários de baixa afluência aos reservatórios. As relações de troca entre energia, uso consuntivo e conservação ambiental são avaliadas, levando-se em conta, também, os efeitos decorrentes da transposição das águas do São Francisco para o Nordeste Setentrional. As perdas na geração de energia decorrentes do aumento da demanda hídrica e do aumento da demanda ambiental são avaliadas. São estimados os custos relacionados às perdas na geração de energia se as demandas consuntivas atingirem o valor outorgado na bacia pelo Poder Público, valor este que não consegue ser plenamente atendido. O modelo proposto pode ser aplicado a quaisquer bacias hidrográficas com múltiplos usos do recurso hídrico.This research presents a study conducted to evaluate the impacts of the hydroelectric power plants operation caused by the multipurpose uses of water resources. There are many conflicts involved in the operation of a reservoir system mainly due to competitive uses of water. That is the case of São Francisco River, located between the Southeast and Northeast regions of Brazil. The hydro system in this region has an installed capacity of 10.7 GW and supports 13% of the Brazilian hydro electrical power. Due to the scarcity of water in this region, the operation of this system has been questioned in the last few years. The competitive uses of water in this region are water supply, irrigation and animal raising. The non-consumptive uses of water are navigation and environmental protection. The electrical sector is planning to review the reservoir operation rules in order to attend these demands. The study was conducted by applying the HIDRO model, which is an optimization PNL model developed with GAMS software that maximizes hydropower production. A new objective function was added to the HIDRO model in order to consider the treatment of energy and water demands the both. The trade-offs among energy, consumptive uses and environment protection are presented. The lack of energy due the increasing water demand implies costs which are evaluated according to some demand scenarios and different scarcity historical periods. Also the effect due the operation of the water transfer system from São Francisco to the neighboring basins is considered.
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Rezende, Jozrael Henriques. "Um estudo sobre a gestão de resíduos e efluentes em marinas, terminais hidroviários de passageiros e embarcações de turismo e lazer no Reservatório de Bariri/Hidrovia Tietê-Paraná." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-01082007-172554/.
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Os aspectos ambientais relacionados às atividades cotidianas de marinas de águas interiores, de terminais hidroviários de passageiros, de embarcações de lazer e de turismo e de outras instalações de apoio, como os estaleiros fluviais, indicam a necessidade da adoção de modelos sustentáveis de gerenciamento destas organizações, pois suas atividades ocorrem diretamente nos corpos d\'água e nas margens de rios e reservatórios, áreas estratégicas para o equilíbrio dos ecossistemas aquáticos e protegidas por uma legislação ambiental rigorosa. Este trabalho sugere alternativas tecnológicas e propõe a implementação de um programa de gestão de resíduos e efluentes, visando adequar a infra-estrutura e a operação de marinas, de terminais de passageiros e de embarcações de turismo, lazer e recreio, à série de normas ISO 14000 e a legislação ambiental, em relação à destinação dos resíduos sólidos, dos resíduos oleosos e dos efluentes sanitários gerados. As propostas foram fundamentadas em dados provenientes de uma avaliação sobre a situação atual das instalações receptoras, dos equipamentos e da gestão de resíduos e efluentes, realizada em uma marina e em uma empresa de navegação de turismo que operam no reservatório de Bariri, na Hidrovia Tietê-Paraná. Os resultados deste trabalho demonstram a importância da implementação de programas de treinamento e de controle dos resíduos e dos efluentes gerados nas atividades em terra e a bordo. Esses programas baseiam-se na redução da geração dos resíduos, na segregação, na reutilização e na reciclagem dos materiais, assim como na educação ambiental e no tratamento e destinação final adequada dos resíduos e efluentes, possibilitando, desta forma, a prevenção, o controle e o combate da poluição dos recursos hídricos, além de proporcionar o aumento da atratividade do empreendimento e da segurança e satisfação de usuários e de funcionários.The environmental aspects related to the daily operations in small craft inland harbors, in passenger waterway terminals, in leisure and tour vessels, in addition to other supporting facilities such as fluvial shipyards, indicate the need for adoption of sustainable models of management of such organizations, due to the fact that their activities are directly related to water bodies and to river banks and reservoirs, which are strategic areas for the aquatic ecosystems balance and protected by a strict environmental legislation. This study focus on technological options and proposes the implementation of a management program of waste and sewage in order to adapt the facilities and the operation of the marinas, passenger terminals and recreational boating to the ISO 14000 serial rules and to the environmental legislation in relation to the destination of solid wastes, oily residues and sewage effluents. The proposals were based on data from an investigation about the current situation of the facilities, the equipment, and the waste and sewage management, carried on both a marina and a tour navigation company which operate in the Bariri reservoir in the Tietê-Paraná Waterway. The results of this study demonstrate the importance of the implementation of programs for training and controlling the waste and sewage produced in shore and off-shore activities. These programs are based on the reduction of the production of waste, on the segregation, on the reutilization and the recycling of the materials, as well as on environmental education and on the treatment and final destination of waste and sewage. This way, they may prevent, control and act against water resources pollution besides making business more attractive and the places safer and more appealing for users and workers.
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LUCENA, Dátia Paula Marques Maia. "Simulações da implantação de ações de gestão no Açude Epitácio Pessoa e seus impactos na crise hídrica em Campina Grande-PB e região." Universidade Federal de Campina Grande, 2018. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/396.
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Reservatórios localizados em regiões semiáridas apresentam alta variabilidade nas afluências hídricas, baixas vazões de regularização, comparadas a outros em climas mais úmidos, e são sujeitos a grandes perdas por evaporação, principalmente quando cheios, fazendo com que a gestão efetiva dos mesmos seja de extrema importância. Este trabalho mostra como modelos matemáticos podem ser utilizados como ferramenta de apoio a tomada de decisão na operação de reservatórios e como medidas de gestão podem afetar situações de racionamento e crise hídrica. O caso de estudo dessa pesquisa é o reservatório Epitácio Pessoa (Boqueirão), localizado em Campina Grande-PB, semiárido brasileiro. O açude Boqueirão recentemente enfrentou a maior crise hídrica desde sua construção, uma gestão não otimizada pode ser apontada como uma das causas do agravamento dessa crise hídrica. É proposta uma metodologia que consiste na definição de oito cenários, compostos por ações ou conjunto de ações que poderiam ter sido tomadas em relação à gestão hídrica do manancial. Dentre o conjunto de ações propostas, tem-se ações meramente gerenciais e outras que envolvem a utilização de técnicas de redução de perdas por evaporação. Tais cenários foram simulados no modelo matemático AcquaNet, para um período de 63 meses, para analisar qual ação teria sido a mais benéfica para a população, e como cada conjunto de ações poderiam ter impactado, quantitativamente, a questão do racionamento em Campina Grande e região. Para fazer a análise e comparação desses cenários, foram utilizados índices de sustentabilidade (confiabilidade, resiliência e vulnerabilidade), bem como os valores dos volumes finais do reservatório e atendimento médio à demanda em cada cenário. A partir destes, foram feitas as comparações entre os cenários para identificação das medidas que causaram maior impacto no sistema. Os resultados encontrados demonstraram que as medidas que incluíram a adoção de técnicas de redução de evaporação na bacia hidráulica do reservatório poderiam ter evitado completamente a adoção do severo racionamento a que a população foi submetida por um longo período de tempo. Adicionalmente, fica demonstrado que modelos matemáticos de simulação podem ser muito úteis na tomada decisão quanto a gestão de reservatórios em épocas de escassez hídrica, principalmente em regiões de clima árido ou semiárido.
Reservoirs located in semi-arid regions present high hydrological variability, low regularization flows, compared to others in more humid climates, and are subject to large evaporation losses, mainly in their periods of high water levels, making their effective management extremely important. This article aims to show how mathematical models can be used as a tool to support decision-making process in the operation of reservoirs and how management measures can affect rationing and water crises. The case study of this research is the Epitacio Pessoa Reservoir (also called Boqueirão), located in the city of Campina Grande-PB, Brazilian semiarid region. The Boqueirão went through the biggest water crisis since its construction, a non-optimized management of these resources can be pointed as one of the causes of these water crisis aggravation. It is proposed a methodology that consists in the definition of eight scenarios, composed by actions or set of actions that could have been taken regarding to the water management of this reservoir during that period. Among the set of actions proposed, there are managing actions and others involving the use of techniques to reduce evaporation losses. The scenarios were simulated with the mathematical model AcquaNet, for a period of 63 months, in order to analyze which action would have been the most beneficial for the population, and how each set of actions could have, quantitatively, affected the water shortage issue in Campina Grande and region. Sustainability indexes (reliability, resilience and vulnerability), reservoir final volumes and average meeting of the water demand requirements, were used to analyze and compare the scenarios. From these results, comparisons were made among the scenarios to identify the measures that would have caused the greatest impact on the system. The results pointed out that measures which included the use of evaporation rates reduction techniques in the reservoir’s hydraulic basin could have completely avoided the adoption of severe rationing to which the population was submitted for a long time. In addition, it is demonstrated that mathematical simulation models can be useful in decision-making processes regarding the management of reservoirs in a water scarcity situation, especially in arid or semi-arid climate regions.
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Allen, Gerald R. "An Analysis of the Fate and Transport of Nutrients in the Upper and Lower Scioto Watersheds of Ohio." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1310663396.
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Garcia, Christopher Jacob. "Management of Global Reservoir Sedimentation: Evaluating RESCON 2 for Sediment Management Alternatives." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7505.
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Reservoir sedimentation occurs as dams impound streams and rivers, preventing the delivery of sediments downstream. Globally, reservoirs lose approximately 40 million acre-ft of storage to sediments each year. Several methods for managing reservoir sedimentation have been developed to help extend project life. In 2017, the World Bank sponsored REServoir CONservation (RESCON) 2, a pre-feasibility program aimed to help users select sediment management practices to consider for more detailed studies.There are two main objectives to this research: 1) perform a sensitivity analysis to understand which parameters require greater precision and which can be roughly approximated, and 2) evaluate RESCON 2 suggested practices to assess the model's accuracy and consistency for providing the optimal solution. Comparisons of the actual sediment management practice will be made with RESCON's results and applicable zones from the Sediment Management Options Diagram (SMOD). Brief descriptions of the SMOD and RESCON 2 will be provided. RESCON-required inputs will be summarized, and some key entries will be presented. Additionally, innovations taken in Japan to modify and retrofit exiting reservoirs with sediment management capabilities will be explored.The sensitivity analysis proves the unit benefit of reservoir yield parameter to be highly sensitive, and users should invest time into determining this value. The sensitivity analysis also illustrates certain processes in RESCON, such as automatically determining the implementation schedule of flushing or a sustainable solution for dredging operations, have great influence over the respective method's analysis. Approximations can be used if these options were selected.Twenty reservoirs from around the world were modeled in RESCON 2, with storage capacities ranging between 152 acre-ft and 31.9 million acre-ft. All sediment management alternatives whose NPV lied within 30% of the highest alternative were deemed practicable for the reservoir. Of the twenty models analyzed in RESCON 2, ten did not practice sediment management. Analyzing only those reservoirs where sediment management is being employed, RESCON predicted the correct or used practice eight out of ten times.Recommendations to improve RESCON include 1) an HSRS operations and maintenance parameter, 2) expanding the unit benefit of reservoir yield parameter into several terms to more explicitly state applicable revenue sources, and 3) creating a list of RESCON model builds, updates, and bug treatments and an option for users to report bugs or other problems.
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Najafiazar, Bahador. "Mathematical Optimization in Reservoir Management." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-27058.
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Getting the most out of a hydrocarbon reservoir is not a trivial task. It takes plentyof interwoven decisions to make. There are many forms of tools that support engineersto make correct decisions. The simplest ones would only display measurementsin a suitable way, and appoint the rest of the decision making processto human knowledge and experience. Complex decision support tools may implementmodel-based estimation and optimization. This work targets methods foroptimization-based decision support.The objective of this study is to formulate, implement and test promising methodsof hydrocarbon production optimization through various test cases. To do this, avarious optimizations algorithm were applied to the simulated reservoir modelsusing the Matlab Reservoir Simulation Toolbox (MRST).
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King, James Allen. "Optimal reservoir operation for drought management." Ohio University / OhioLINK, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1183649698.
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Buchanan, Crawford S. "Benders decomposition method in reservoir management." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/22790.
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Multi-stage stochastic linear programming provides a framework in which to model and solve decision making problems that contain uncertain data. In this thesis the main stages in the process of modelling and solving a large-scale multi-stage stochastic linear programme (MSLP) are examined. The principal motivation for this research is the study of the electricity generation network of Southern Brazil. This network contains a high proportion of hydro-electric generation plants, and so the stochasticity of the future inflows has a large influence on decisions. The formulation of MSLPS is difficult within existing algebraic modelling languages. Many MSLPs can be formulation as a set of recurrences. We present a new algebraic modelling language, sMAGIC, that uses the recursive definition of sub-models to aid in the specification of MSLPs. The Benders Decomposition algorithm exploits the sparse structure of MSLPs, achieving a considerable reduction in the time taken to solve MSLPs over direct solution methods, such as the simplex method. In addition, the basic Benders Decomposition algorithm can be extended and is well suited to parallelisation. We present results that show that some of the extensions to the basic algorithm improve the performance of the solver in all cases, while others provide improvements only for particular test problems. The research from our parallel implementation on a network of workstations give near linear speedups. Sampling techniques can be incorporated within the Benders Decomposition method. This allows an approximation to the solution of MSLPs that are too large to solve using Benders Decomposition to be obtained. A Benders Decomposition algorithm that incorporates Monte Carlo is guaranteed to converge asymptotically to the actual solution. To improve the speed of this algorithm, an additive approximation to the cost function is used to guide an importance sampling technique.
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Adams, Lauren. "Optimized Reservoir Management for Downstream Environmental Purposes." Thesis, University of California, Davis, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10973511.
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In regulated rivers, reservoir operation decisions largely determine downstream river temperature and flow. Computational methods can minimize the risk and uncertainty of making regrettable environmental release decisions and aid operations planning and performance prediction. Mathematical modeling in particular can optimize the timing and magnitude of reservoir release decisions for downstream benefit while accounting for seasonal uncertainty, water storage impact, and competing water demands. This dissertation uses optimization and modeling techniques, modifying traditional optimization modeling to include temporal correlation in outcome variables and incorporating long-term planning and risk management into prescribed reservoir operations. The proposed method is implemented in one case, a) with a state variable that tracks outcome benefits over time (fish population size) and, in another case, b) with a maximin stochastic dynamic program solution algorithm that maximizes net operational benefit and minimizes worst-case outcomes (for cold water habitat delivery). This method is particularly useful for environmental flow management, when the water quality and quantity of the river and reservoir in one time step affect the quantity and quality in the reservoir and the river for later periods. Better solutions with these methods internalize risk and hedge releases at the beginning of an operating season to maximize downstream benefit and reduce the probability of catastrophe for the season and future years. Maximizing the minimum cold-water habitat area over months of a season or multiple years, or maximizing a river indicator variable explicitly, could likely help, for example, maximize an out-migrating salmon smolt population downstream. The method is demonstrated with a case study optimizing environmental releases from Folsom Dam and another optimizing temperature management from Shasta Dam in northern California. These results inform general rules for environmental flow management and temperature management of reservoirs, with specific policy recommendations for both Folsom and Shasta reservoirs. In both cases, the added value from employing hedging rules help reservoir operations minimize the risk of environmental catastrophe and conserve storage both within an operating season and across years.
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Joinson, Daniel. "Subterranean wireless communication for oil reservoir management." Thesis, University of Cambridge, 2005. https://www.repository.cam.ac.uk/handle/1810/272141.
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Gomes, Jorge S. "Reservoir description of the Arab-C Dukhan carbonate reservoir for improved reservoir management and use as a subsurface analogue." Thesis, Heriot-Watt University, 2001. http://hdl.handle.net/10399/1141.
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Cetinkaya, Oguz Kagan. "Management Of Reservoir Sedimentation Case Studies From Turkey." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607016/index.pdf.
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Siltation is becoming a big problem as the dams get older all over the world. Conservation and sustainable management of existing reservoirs is gaining more importance than constructing new dams. In this study the program RESCON, which is outcome of a World Bank sponsored project, has been used to examine sediment removal strategies (flushing, hydrosuction sediment removal, dredging and trucking) for four dams of Turkey namely Çubuk I Dam, Bayindir Dam, ivriz Dam and Borç
ka Dam. Sediment measurements are made by governmental agencies in Turkey. In this study characteristics of these measurements will be presented for the future sediment related studies. Then sediment removal strategies which were used in RESCON will be introduced. Evaluation of RESCON results have been made and compared with previous studies for verification except Borç
ka Dam, since it is under construction.
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Mamede, George Leite. "Reservoir sedimentation in dryland catchments : modelling and management." Phd thesis, Universität Potsdam, 2008. http://opus.kobv.de/ubp/volltexte/2008/1704/.
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Semi-arid environments are mainly characterized by scarce water resources and are usually subject to risks of water stress. In these regions, water supply for drinking and irrigation purposes depends strongly on storage in surface reservoirs and sediment deposition in these reservoirs affects adversely the water storage.
In order to reproduce the complex behaviour of sediment deposition in reservoirs located in semi-arid environments and the effects of using sediment management techniques, a reservoir sedimentation model is developed and coupled within the WASA-SED model, which simulates rainfall-runoff processes and sediment transport at the hillslope and river network.
The reservoir sedimentation model consists of two modelling approaches, which may be applied according to reservoir size and data availability. For reservoirs with information about their geometric features (reservoir topography, stage-area and stage-volume curves) and physical properties of sediment deposits, such as deposition thickness, grain size distribution of sediment deposits and sediment densities, a detailed modelling approach of reservoir sedimentation may be applied. For reservoirs without those characteristics, a simplified modelling approach is used.
The detailed modelling approach of reservoir sedimentation enables the assessment of sediment deposition pattern in reservoirs and the evaluation of sediment release efficiency of sediment management techniques. It simulates sediment transport along the longitudinal profile of a reservoir. The reservoir is divided into cross sections to elaborate the sediment budget. The sediment transport component is calculated using a non-uniform sediment transport approach based on the concept of sediment carrying capacity. Four different sediment-transport equations can be selected for the simulations.
The simplified modelling approach of reservoir sedimentation is suitable to simulate water and sediment transfer in dense reservoirs network. Nevertheless, it allows simulating neither sediment management techniques, nor spatial distribution of sedimentation. In this approach, the reservoirs are classified into small and strategic reservoirs according to their location and size. Strategic reservoirs are medium and large-sized reservoirs located on main rivers at the sub-basin’s outlet or reservoirs of particular interest. The small reservoirs are located at tributary streams and represented in the model in an aggregate manner by grouping them into size classes according to their storage capacity. A cascade routing scheme is used to describe the upstream-downstream position of the reservoir classes. The water and sediment balances of small reservoirs are computed for one hypothetical representative reservoir of mean characteristics. Sediment trapping efficiency and effluent grain size distribution are estimated using the overflow rate concept.
Three model applications are carried out within this research, as follows:
• The detailed modelling approach of reservoir sedimentation is applied to the 92.2 Mm³ Barasona Reservoir, located in the foothills of the Central Pyrenees (Aragon, Spain). A two-stage calibration was performed to account for changes on the sediment deposition pattern caused by sediment management. The reservoir sedimentation model is then validated for another simulation period which confirms that the processes related to reservoir sedimentation are well represented by the model.
• An application is carried out to the 933-km² Benguê catchment, located in the semi-arid region of Northeast Brazil. The catchment is characterized by a dense reservoir network, covering almost 45% of the catchment area, with a significant lack of data. Water and sediment balances of those reservoirs are computed using the simplified modelling approach. Three spatial configurations describing the cascade routing scheme are tested.
• The reservoir sedimentation model is applied again to the Barasona reservoir to evaluate the sediment release efficiency of sediment management strategies. Cost analysis is presented to help in the choice of the most promising sediment management technique for that situation. Thus, the model enables the assessment of technical features of the sediment management strategies.
Overall, simulation results are characterized by large uncertainties, partly due to low data availability and also due to uncertainties of the model structure to adequately represent the processes related to reservoir sedimentation.Semiaride Gebiete sind hauptsächlich durch geringe Wasserressourcen gekennzeichnet und unterliegen häufig dem Risiko der Wasserknappheit. In diesen Gebieten ist die Wasserbereitstellung für Bewässerung und Trinkwasserversorgung stark von der oberflächlichen Speicherung in Stauseen abhängig, deren Wasserverfügbarkeit nachteilig durch Sedimentablagerung beeinflusst wird. Zur Wiedergabe des komplexen Sedimentablagerungsverhaltens in Stauseen von semiariden Gebieten und die Auswirkungen von Sedimentmanagementmaßnahmen wird ein Sedimentationsmodell entwickelt und mit dem WASA-SED Modell gekoppelt, das für die Modellierung der Abflussbildung und des Sedimenttransportes in Einzugsgebieten geeignet ist. Das Sedimentationsmodell beinhaltet zwei Ansätze, die unter der Berücksichtigung verschiedener Stauseengrößenklassen und Datenverfügbarkeit eingesetzt werden können. Für die Stauseen mit verfügbaren Informationen über ihre geometrischen Eigenschaften (wie Stauseetopographie und Höhe-Fläche-Volumen-Beziehung) und weitere Kenngrößen wie Ablagerungsmächtigkeit, Korngrößenverteilung und Sedimentdichte, kann ein detaillierter Modellansatz für die Sedimentablagerung verwendet werden. Wo diese Informationen nicht verfügbar sind, wird auf einen vereinfachten Ansatz zurückgegriffen. Der detaillierte Modellansatz ermöglicht die Betrachtung von Ablagerungsmustern im Stausee und Einschätzungen über die Effektivität von Sedimentmanagementmaßnahmen hinsichtlich der Sedimententlastung. Dieser Ansatz beruht auf der Simulation des Sedimenttransportes entlang eines Stauseelängsprofils. Für die Berechnung des Sedimenttransfers wird der Stauseekörper in einer Folge von Querprofilen repräsentiert. Der Sedimenttransport wird dabei korngrößenspezifisch entsprechend der Transportkapazität berechnet. Dafür stehen vier verschiedenen Sedimenttransportgleichungen zur Verfügung. Der vereinfachte Modellansatz ist für die Simulation des Sedimenttransfers in Gebieten mit hoher Stauseedichte geeignet, jedoch können weder Sedimentmanagementmaßnahmen noch die räumliche Verteilung der Ablagerungen berücksichtigt werden. Dafür werden die Stauseen in Abhängigkeit von ihrer Größe und Position in kleine und strategische Stauseen unterteilt. Dabei sind strategische Stausseen solche mit mittlerem bis großem Volumen sowie einer Lage im Hauptgerinne oder solche mit sonstiger besonderer Bedeutung. Kleine Stauseen hingegen befinden sich an den Nebenflüssen und werden im Modell in aggregierter Form durch ihre Einteilung in Stauseegrößenklassen repräsentiert. Ein Kaskadenverfahren wird für den Wasser- und Sedimentlauf zwischen den Stauseeklassen verwendet. Dabei werden für jede Stauseeklasse der Wasser- sowie Sedimenthaushalt für einen hypothetischen repräsentativen Stausee mit mittleren Eigenschaften berechnet. Die Sedimentaufnahme und die Korngrößenverteilung des abgegebenen Sediments werden mit dem Überlaufanteil-Ansatz berechnet. In dieser Studie werden drei Modellanwendungen vorgestellt: • Für den 92,2 Mio.m³-großen Barasona-Stausee (Vorland der Zentralpyrenäen, Aragon, Spanien) wird die Modellierung der Sedimentablagerung mit dem detaillierten Modellansatz vorgenommen. Die Kalibrierung dafür wurde in zwei Schritten durchgeführt, um Änderungen im Stauseemanagement Rechnung zu tragen. Die ModellValidierung wird schließlich für eine andere Simulationsperiode vorgenommen. Dabei wird ersichtlich, dass die Prozesse der Sedimentablagerung gut durch das Modell wiedergegeben werden. • Das Modell wird auf das 933 km²-große Benguê-Einzugsgebiet, das sich im semiariden Nordosten Brasiliens befindet, angewendet. Dieses Einzugsgebiet ist durch eine hohe Dichte an kleinen Stauseen, charakterisiert, die fast 45% des Gebietes umfasst, wofür jedoch wenige Messdaten verfügbar sind. Deshalb werden der Wasser- und Sedimenttransport mit dem vereinfachten Modellansatz berechnet. Dabei werden drei Konfigurationen des Kaskadenverfahrens getestet. • Die Modellanwendung erfolgt erneut für den Barasona-Stausee bezüglich der Effektivität der Sedimentmanagementmaßnahmen. Eine Kostenanalyse ermöglicht die Auswahl geeigneter Maßnahmen für den Stausee. Dadurch wird eine Beurteilung der verschiedenen Sedimentmanagementstrategien ermöglicht. Im Allgemeinen unterliegen die Simulationsergebnisse großen Unsicherheiten, teilweise wegen der geringen Datenverfügbarkeit, andererseits durch die Unsicherheiten in der Modellstruktur zur korrekten Wiedergabe der Sedimentablagerungsprozesse.