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- Title
- Risk Management in Reservoir Operations in the Context of Undefined Competitive Consumption.
- Creator
-
Salami, Yunus, Nnadi, Fidelia, Wang, Dingbao, Chopra, Manoj, Rowney, Alexander, Divo, Eduardo, University of Central Florida
- Abstract / Description
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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....
Show moreDams 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.
Show less - Date Issued
- 2012
- Identifier
- CFE0004593, ucf:49193
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004593
- Title
- FRAMEWORKS FOR ENVIRONMENTAL POLICYMAKING IN BRAZIL AND CHILE: A COMPARATIVE POLICYMAKING ANALYSIS OF THE BELO MONTE AND HIDROAYS�N DAMS.
- Creator
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Vogan, Robert J, Wilson, Bruce M., University of Central Florida
- Abstract / Description
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A global proliferation of large dam construction since the 1950s has been accompanied by scientific research challenging the benefit of these projects while drawing attention to their numerous negative environmental and social impacts. The institutions that assess the costs and benefits associated with large dam proposals, creating policies either approving, altering, or disapproving them, collectively form what is known as a policymaking framework. Examining these frameworks allows observers...
Show moreA global proliferation of large dam construction since the 1950s has been accompanied by scientific research challenging the benefit of these projects while drawing attention to their numerous negative environmental and social impacts. The institutions that assess the costs and benefits associated with large dam proposals, creating policies either approving, altering, or disapproving them, collectively form what is known as a policymaking framework. Examining these frameworks allows observers to trace policies through outlined decision-making processes and can help to reveal inherent biases within those systems that may impact policy outcomes. Often, divergent policy outcomes, like the those observed in the cases of the Belo Monte dam in Brazil and HidroAys�n dam in Chile, are a result of variations in the environmental policymaking frameworks of the deviating cases. The subjects of this study present similar arrangements of costs and benefits but resulted incongruous policy outcomes, specifically that the HidroAys�n dam was not built while the Belo Monte dam is currently under construction. Existing bodies of literature outlining the environmental policymaking frameworks of Chile and Brazil fail to fully address the influence of external variables, including presidential influence, corruption, and electoral politics, on these cases. This project synthesizes an outline of the environmental policymaking frameworks of Chile and Brazil from existing literature and uses the divergent cases of the Belo Monte and HidroAys�n dams to provide evidence for the incorporation of these external variables to better understand the incongruous policy outcomes these frameworks produce.
Show less - Date Issued
- 2016
- Identifier
- CFH2000129, ucf:46011
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000129
- Title
- Seepage and Stability Analysis of the Earth Dams under Drawdown Conditions by using the Finite Element Method.
- Creator
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Al-Labban, Salama, Chopra, Manoj, Mackie, Kevin, Wang, Dingbao, Elshennawy, Ahmad, University of Central Florida
- Abstract / Description
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One of the major concerns in the behavior of an earth dam is the change in the exit gradient and the impact on the slope stability under drawdown conditions. Drawdown can cause increased seepage forces on the upstream slope which may result in the movement of soil particles in the flow direction and cause erosion problems. In this research, a numerical approach, based on the finite element method (FEM) is used to analyze the seepage through the dam and its foundation to study exit gradients...
Show moreOne of the major concerns in the behavior of an earth dam is the change in the exit gradient and the impact on the slope stability under drawdown conditions. Drawdown can cause increased seepage forces on the upstream slope which may result in the movement of soil particles in the flow direction and cause erosion problems. In this research, a numerical approach, based on the finite element method (FEM) is used to analyze the seepage through the dam and its foundation to study exit gradients and slope stability under both steady-state and transient conditions. The results show that a central core is important in reducing the flux through the dam. Constructing a cutoff under the core further increases the efficiency of the core and lowers the phreatic line. However, it is seen that the submerged weight increases when the earth dam with a core or with a complete cutoff which causes higher water flux to flow out of the dam under the drawdown condition. The exit gradient at the upstream slope may reach critical levels and cause failure of the dam due to erosion. Adding an upstream filter is studied as a possible solution to this problem. Two configurations of the filters are modeled and the slope filter configuration performed best in reducing the exit gradient at the upstream face. A low permeability core with a cutoff increases deformation of the soil because of increased saturated areas in the upstream region. The factor of safety of the slope is also reduced because of the increased buoyancy of the soil at the upstream side of the dam. The soil properties of the upstream filter have a significant influence on the slope stability against sliding. An upstream slope filter increases the stability of the slope while a central filter decreases it.
Show less - Date Issued
- 2018
- Identifier
- CFE0007303, ucf:52167
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007303
- Title
- "ANALYZING THE EFFECTS OF SINGLE-SOURCING METHODOLOGIES ON THE ROLE OF THE TECHNICAL COMMUNICATOR".
- Creator
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Boehl, Jeremy, Applen, J.D., University of Central Florida
- Abstract / Description
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This thesis discusses the specific effects of single sourcing methodologies on the role of the technical communicator, his or her job responsibilities, qualifications, collaboration with coworkers, employee and employer expectations, and the effects on career progression. The methodologies discussed included all types of single sourcing methods for technical documentation (such as XML-based), advanced and non-advanced Content Management Systems (CMS), and Digital Asset Management (DAM)...
Show moreThis thesis discusses the specific effects of single sourcing methodologies on the role of the technical communicator, his or her job responsibilities, qualifications, collaboration with coworkers, employee and employer expectations, and the effects on career progression. The methodologies discussed included all types of single sourcing methods for technical documentation (such as XML-based), advanced and non-advanced Content Management Systems (CMS), and Digital Asset Management (DAM) systems. Other topics explored are an overview of single sourcing for technical documentation, a comparison of the "craftsman model" to the current trend of single sourcing and structured content, specific effects on technical communicators such as role changes, the effects of incorporating XML into a technical communicator's daily work environment, and the effects of other emerging technologies such as advanced CMS and DAM systems on technical communicators. General findings include that the practice of single sourcing, whether a positive or negative development, has continued and likely will continue to increase in technical communication groups within organizations. Single sourcing, especially for dynamic, customized content is also increasing because of the current marketplace, but works best via the use of a CMS and other systems used by large organizations. Single sourcing is also best implemented after extensive strategic planning and training of employees. Many technical communicators will have to accept new roles and positions, the direction of which is greatly impacted by the extent of their skills. Recommendations are made for additional research on the effects of single sourcing implementation on the technical communicator, and how to adapt to changes. Additional research is also needed on XML, DITA (Darwinian Information Typing Architecture), and DAM systems, all related specifically to technical communication.
Show less - Date Issued
- 2006
- Identifier
- CFE0001302, ucf:47031
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001302