Current Search:  Tides (x)

View All Items

  • CSV Spreadsheet
(1 - 7 of 7)
FINITE ELEMENT MODELING OF TIDES AND CURRENTS OF THE PASCAGOULA RIVER
Title
FINITE ELEMENT MODELING OF TIDES AND CURRENTS OF THE PASCAGOULA RIVER.
Creator
Wang, Qing, Hagen, Scott, University of Central Florida
Abstract / Description
This thesis focuses on the simulation of astronomic tides of the Pascagoula River. The work is comprised of five steps: 1) Production of a digital elevation model describing the entire Pascagoula River system; 2) Development of an inlet-based, unstructured mesh for inbank flow to better understand the basis of the hydrodynamics within the Pascagoula riverine system. In order to assist in the mesh development, a toolbox was constructed to implement one-dimensional river cross sections into the...
Show moreThis thesis focuses on the simulation of astronomic tides of the Pascagoula River. The work is comprised of five steps: 1) Production of a digital elevation model describing the entire Pascagoula River system; 2) Development of an inlet-based, unstructured mesh for inbank flow to better understand the basis of the hydrodynamics within the Pascagoula riverine system. In order to assist in the mesh development, a toolbox was constructed to implement one-dimensional river cross sections into the two-dimensional model; 3) Implementation of a sensitivity analysis of the Pascagoula River two inlet system to examine the inlet effects on tidal propagation; 4) Improvement of the inlet-based model by performing a preliminary assessment of a spatially varied bottom friction; 5) Implementation of an advection analysis to reveal its influence on the flow velocity and water elevation within the domain. The hydrodynamic model employed for calculating tides is ADCIRC-2DDI (ADvanced CIRCulation Model for Shelves, Coasts and Estuaries, Two-Dimensional Depth Integrated). This finite element based model solves the shallow water equations in their full nonlinear form. Boundary conditions including water surface elevation at the off-shore boundary and tidal potential terms allow the full simulation of astronomic tides. The improved astronomic tide model showed strong agreement with the historical data at seven water level monitoring gauge stations. The main conclusions of this research are: 1) The western inlet of the Pascagoula River is more dominant than the eastern inlet; however, it is necessary to include both inlets in the model. 2) Although advection plays a significant role in velocity simulation, water elevations are insensitive to advection. 3) The astronomic model is sensitive to bottom friction (both global and spatial variations); therefore, a spatially varied bottom friction coefficient is suggested. As a result of this successful effort to produce an astronomic tide model of the Pascagoula River, a comprehensive storm surge model can be developed. With the addition of inundation areas the surge model can be expected to accurately predict storm tides generated by hurricanes along the Gulf Coast.
Show less
Date Issued
2008
Identifier
CFE0002291, ucf:47840
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002291
ANALYSIS OF THE PHYSICAL FORCING MECHANISMS INFLUENCING SALINITY TRANSPORT FOR THE LOWER ST. JOHNS RIVER
Title
ANALYSIS OF THE PHYSICAL FORCING MECHANISMS INFLUENCING SALINITY TRANSPORT FOR THE LOWER ST. JOHNS RIVER.
Creator
Giardino, Derek, Hagen, Scott, University of Central Florida
Abstract / Description
The focus of this thesis is the forcing mechanisms incorporated with salinity transport for the Lower St. Johns River. There are two primary analyses performed: a historical data analysis of primary forcing mechanisms to determine the importance of each individual influence, and a tidal hydrodynamics analysis for the Lower St. Johns River to determine the required tidal constituents for an accurate resynthesis. This thesis is a preliminary effort in understanding salinity transport for the...
Show moreThe focus of this thesis is the forcing mechanisms incorporated with salinity transport for the Lower St. Johns River. There are two primary analyses performed: a historical data analysis of primary forcing mechanisms to determine the importance of each individual influence, and a tidal hydrodynamics analysis for the Lower St. Johns River to determine the required tidal constituents for an accurate resynthesis. This thesis is a preliminary effort in understanding salinity transport for the Lower St. Johns River for engineering projects such as the dredging of navigation canals and freshwater withdrawal from the river. The analysis of the physical forcing mechanisms is performed by examining the impact of precipitation, tides, and wind advection on historical salinity measurements. Three 30-day periods were selected for the analysis, to correspond with representative peak, most-variable, and low-salinity periods for 1999. The analysis displays that wind advection is the dominant forcing mechanism for the movement of salinity over a 30 day duration; however all mechanisms have an impact at some level. The dominant forcing mechanism is also dependent on the period of record examined where tidal influence is vital for durations of hours to a day, while freshwater inflow has more significance over a longer period due to climatological variation. A two-dimensional finite difference numerical model is utilized to generate a one month tidal elevations and velocities simulations that incorporates geometry, nonlinear advection and quadratic bottom friction. Several combinations of tidal constituents are extracted from this modeled tidal signal to investigate which combination of tidal constituents produces an accurate tidal resynthesis for the Lower St. Johns River. The analysis displays the need for 39 total tidal harmonic constituents to accurately resynthesize the original tidal signal. Additionally, due to the nonlinear nature of shallow water, the influence of the overtides for upstream or downstream locations in the Lower St. Johns River is shown to be spatially variable for different frequencies depending on the geometry. The combination of the constituent analysis and the historical analysis provides the basis information needed for the development of an accurate salinity transport model for the Lower St. Johns River.
Show less
Date Issued
2009
Identifier
CFE0002665, ucf:48197
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002665
OPTIMIZATION OF AN UNSTRUCTURED FINITE ELEMENT MESH FOR TIDE AND STORM SURGE MODELING APPLICATIONS IN THE WESTERN NORTH ATLANTIC OCEAN
Title
OPTIMIZATION OF AN UNSTRUCTURED FINITE ELEMENT MESH FOR TIDE AND STORM SURGE MODELING APPLICATIONS IN THE WESTERN NORTH ATLANTIC OCEAN.
Creator
Kojima, Satoshi, Hagen, Scott, University of Central Florida
Abstract / Description
Recently, a highly resolved, finite element mesh was developed for the purpose of performing hydrodynamic calculations in the Western North Atlantic Tidal (WNAT) model domain. The WNAT model domain consists of the Gulf of Mexico, the Caribbean Sea, and the entire portion of the North Atlantic Ocean found west of the 60° W meridian. This high resolution mesh (333K) employs 332,582 computational nodes and 647,018 triangular elements to provide approximately 1.0 to 25 km node spacing. In the...
Show moreRecently, a highly resolved, finite element mesh was developed for the purpose of performing hydrodynamic calculations in the Western North Atlantic Tidal (WNAT) model domain. The WNAT model domain consists of the Gulf of Mexico, the Caribbean Sea, and the entire portion of the North Atlantic Ocean found west of the 60° W meridian. This high resolution mesh (333K) employs 332,582 computational nodes and 647,018 triangular elements to provide approximately 1.0 to 25 km node spacing. In the previous work, the 333K mesh was applied in a Localized Truncation Error Analysis (LTEA) to produce nodal density requirements for the WNAT model domain. The goal of the work herein is to use these LTEA-based element sizing guidelines in order to obtain a more optimal finite element mesh for the WNAT model domain, where optimal refers to minimizing nodes (to enhance computational efficiency) while maintaining model accuracy, through an automated procedure. Initially, three finite element meshes are constructed: 95K, 60K, and 53K. The 95K mesh consists of 95,062 computational nodes and 182,941 triangular elements providing about 0.5 to 120 km node spacing. The 60K mesh contains 60,487 computational nodes and 108,987 triangular elements. It has roughly 0.5 to 185 km node spacing. The 53K mesh includes 52,774 computational nodes and 98,365 triangular elements. This is a particularly coarse mesh, consisting of approximately 0.5 to 160 km node spacing. It is important to note that these three finite element meshes were produced automatically, with each employing the bathymetry and coastline (of various levels of resolution) of the 333K mesh, thereby enabling progress towards an optimal finite element mesh. Tidal simulations are then performed for the WNAT model domain by solving the shallow water equations in a time marching manner for the deviation from mean sea level and depth-integrated velocities at each computational node of the different finite element meshes. In order to verify the model output and compare the performance of the various finite element mesh applications, historical tidal constituent data from 150 tidal stations located within the WNAT model domain are collected and examined. These historical harmonic data are applied in two types of comparative analyses to evaluate the accuracy of the simulation results. First, qualitative comparisons are based on visual sense by utilizing plots of resynthesized model output and historical tidal constituents. Second, quantitative comparisons are performed via a statistical analysis of the errors between model response and historical data. The latter method elicits average phase errors and goodness of average amplitude fits in terms of numerical values, thus providing a quantifiable way to present model error. The error analysis establishes the 53K finite element mesh as optimal when compared to the 333K, 95K, and 60K meshes. However, its required time step of less than ten seconds constrains its application. Therefore, the 53K mesh is manually edited to uphold accurate simulation results and to produce a more computationally efficient mesh, by increasing its time step, so that it can be applied to forecast tide and storm surge in the Western North Atlantic Ocean on a real-time basis.
Show less
Date Issued
2005
Identifier
CFE0000565, ucf:46421
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000565
ANALYSIS, MODELING, AND SIMULATION OF THE TIDES IN THE LOXAHATCHEE RIVER ESTUARY (SOUTHEASTERN FLORIDA).
Title
ANALYSIS, MODELING, AND SIMULATION OF THE TIDES IN THE LOXAHATCHEE RIVER ESTUARY (SOUTHEASTERN FLORIDA).
Creator
Bacopoulos, Peter, Hagen, Scott, University of Central Florida
Abstract / Description
Recent cooperative efforts between the University of Central Florida, the Florida Department of Environmental Protection, and the South Florida Water Management District explore the development of a two-dimensional, depth-integrated tidal model for the Loxahatchee River estuary (Southeastern Florida). Employing a large-domain approach (i.e., the Western North Atlantic Tidal model domain), two-dimensional tidal flows within the Loxahatchee River estuary are reproduced to provide: 1)...
Show moreRecent cooperative efforts between the University of Central Florida, the Florida Department of Environmental Protection, and the South Florida Water Management District explore the development of a two-dimensional, depth-integrated tidal model for the Loxahatchee River estuary (Southeastern Florida). Employing a large-domain approach (i.e., the Western North Atlantic Tidal model domain), two-dimensional tidal flows within the Loxahatchee River estuary are reproduced to provide: 1) recommendations for the domain extent of an integrated, surface/groundwater, three-dimensional model; 2) nearshore, harmonically decomposed, tidal elevation boundary conditions. Tidal simulations are performed using a two-dimensional, depth-integrated, finite element-based code for coastal and ocean circulation, ADCIRC-2DDI. Multiple variations of an unstructured, finite element mesh are applied to encompass the Loxahatchee River estuary and different spatial extents of the Atlantic Intracoastal Waterway (AIW). Phase and amplitude errors between model output and historical data are quantified at five locations within the Loxahatchee River estuary to emphasize the importance of including the AIW in the computational domain. In addition, velocity residuals are computed globally to reveal significantly different net circulation patterns within the Loxahatchee River estuary, as depending on the spatial coverage of the AIW.
Show less
Date Issued
2006
Identifier
CFE0000925, ucf:46755
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000925
ESTUARINE INFLUENCE ON TIDALLY DRIVEN CIRCULATION IN THE SOUTH ATLANTIC BIGHT
Title
ESTUARINE INFLUENCE ON TIDALLY DRIVEN CIRCULATION IN THE SOUTH ATLANTIC BIGHT.
Creator
Bacopoulos, Peter, Hagen, Scott, University of Central Florida
Abstract / Description
A high-resolution, finite element-based, shallow water equation model is developed to simulate the tides in the South Atlantic Bight. The model is constructed to include all of the estuarine features along the southeastern United States seaboard: coastal inlets, rivers and tidal creeks, sounds and lagoons, intertidal zones including salt marshes and mangrove swamps, and the Atlantic Intracoastal Waterway. The estuaries are represented in the finite element mesh using triangular elements with...
Show moreA high-resolution, finite element-based, shallow water equation model is developed to simulate the tides in the South Atlantic Bight. The model is constructed to include all of the estuarine features along the southeastern United States seaboard: coastal inlets, rivers and tidal creeks, sounds and lagoons, intertidal zones including salt marshes and mangrove swamps, and the Atlantic Intracoastal Waterway. The estuaries are represented in the finite element mesh using triangular elements with side lengths on the order of tens of meters. Also incorporated into the model is a spatially distributed bottom friction parameterization, based on the various landcover and benthic characteristics in the domain. The motivation to use this comprehensive representation of the system was inspired by a desire to capably account for the full estuarine tidal physics. In this approach, no calibration is performed and the model is used as a tool to assess the physical processes it describes. Upon its development, the model is first validated by accurately simulating tidal hydrodynamics in the South Atlantic Bight including the described estuaries. Variants of the model are then constructed by selectively removing estuarine features from the domain. All model representations are subsequently applied in nearly identical simulations: the only differing factor between the simulations being the inland extent of the estuaries described. The solutions are compared with respect to including versus excluding the estuarine features of the domain. Where water surface elevations are shown to be unaffected by the estuarine features of the South Atlantic Bight, tidal velocities exhibit far more sensitivity. This effect is pronounced locally, with regional effects extending offshore. Further analysis is performed on cross-sectional flows recomposed locally and on tidal energetics diagnosed throughout the domain. It is discovered that the high frictional environment of the vast estuarine surface area plays a role in local and regional tidal circulation in the South Atlantic Bight.
Show less
Date Issued
2009
Identifier
CFE0002891, ucf:48028
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002891
RED TIDE: A FEATURE LENGTH MOTION PICTURE
Title
RED TIDE: A FEATURE LENGTH MOTION PICTURE.
Creator
Gallina, Dino, Wolfe, Jesse, University of Central Florida
Abstract / Description
The following document provides insight into the uncharted process of producing a micro-budget feature length film. This paper aims to document my growth as an artist in terms of storytelling and filmmaking as well as the development and production process. Red Tide: A Feature Length Motion Picture includes elements from each phase of the production process, from story and script development to marketing and distribution. This document reflects on the obstacles we faced and the solutions we...
Show moreThe following document provides insight into the uncharted process of producing a micro-budget feature length film. This paper aims to document my growth as an artist in terms of storytelling and filmmaking as well as the development and production process. Red Tide: A Feature Length Motion Picture includes elements from each phase of the production process, from story and script development to marketing and distribution. This document reflects on the obstacles we faced and the solutions we implemented during the process of creating a feature length motion picture on an undersized budget.
Show less
Date Issued
2010
Identifier
CFE0003192, ucf:48586
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0003192
Incorporating Remotely Sensed Data into Coastal Hydrodynamic Models: Parameterization of Surface Roughness and Spatio-Temporal Validation of Inundation Area
Title
Incorporating Remotely Sensed Data into Coastal Hydrodynamic Models: Parameterization of Surface Roughness and Spatio-Temporal Validation of Inundation Area.
Creator
Medeiros, Stephen, Hagen, Scott, Weishampel, John, Wang, Dingbao, Yeh, Gour-Tsyh, University of Central Florida
Abstract / Description
This dissertation investigates the use of remotely sensed data in coastal tide and inundation models, specifically how these data could be more effectively integrated into model construction and performance assessment techniques. It includes a review of numerical wetting and drying algorithms, a method for constructing a seamless digital terrain model including the handling of tidal datums, an investigation into the accuracy of land use / land cover (LULC) based surface roughness...
Show moreThis dissertation investigates the use of remotely sensed data in coastal tide and inundation models, specifically how these data could be more effectively integrated into model construction and performance assessment techniques. It includes a review of numerical wetting and drying algorithms, a method for constructing a seamless digital terrain model including the handling of tidal datums, an investigation into the accuracy of land use / land cover (LULC) based surface roughness parameterization schemes, an application of a cutting edge remotely sensed inundation detection method to assess the performance of a tidal model, and a preliminary investigation into using 3-dimensional airborne laser scanning data to parameterize surface roughness.A thorough academic review of wetting and drying algorithms employed by contemporary numerical tidal models was conducted. Since nearly all population centers and valuable property are located in the overland regions of the model domain, the coastal models must adequately describe the inundation physics here. This is accomplished by techniques that generally fall into four categories: Thin film, Element removal, Depth extrapolation, and Negative depth. While nearly all wetting and drying algorithms can be classified as one of the four types, each model is distinct and unique in its actual implementation.The use of spatial elevation data is essential to accurate coastal modeling. Remotely sensed LiDAR is the standard data source for constructing topographic digital terrain models (DTM). Hydrographic soundings provide bathymetric elevation information. These data are combined to form a seamless topobathy surface that is the foundation for distributed coastal models. A three-point inverse distance weighting method was developed in order to account for the spatial variability of bathymetry data referenced to tidal datums. This method was applied to the Tampa Bay region of Florida in order to produce a seamless topobathy DTM.Remotely sensed data also contribute to the parameterization of surface roughness. It is used to develop land use / land cover (LULC) data that is in turn used to specify spatially distributed bottom friction and aerodynamic roughness parameters across the model domain. However, these parameters are continuous variables that are a function of the size, shape and density of the terrain and above-ground obstacles. By using LULC data, much of the variation specific to local areas is generalized due to the categorical nature of the data. This was tested by comparing surface roughness parameters computed based on field measurements to those assigned by LULC data at 24 sites across Florida. Using a t-test to quantify the comparison, it was proven that the parameterizations are significantly different. Taking the field measured parameters as ground truth, it is evident that parameterizing surface roughness based on LULC data is deficient.In addition to providing input parameters, remotely sensed data can also be used to assess the performance of coastal models. Traditional methods of model performance testing include harmonic resynthesis of tidal constituents, water level time series analysis, and comparison to measured high water marks. A new performance assessment that measures a model's ability to predict the extent of inundation was applied to a northern Gulf of Mexico tidal model. The new method, termed the synergetic method, is based on detecting inundation area at specific points in time using satellite imagery. This detected inundation area is compared to that predicted by a time-synchronized tidal model to assess the performance of model in this respect. It was shown that the synergetic method produces performance metrics that corroborate the results of traditional methods and is useful in assessing the performance of tidal and storm surge models. It was also shown that the subject tidal model is capable of correctly classifying pixels as wet or dry on over 85% of the sample areas.Lastly, since it has been shown that parameterizing surface roughness using LULC data is deficient, progress toward a new parameterization scheme based on 3-dimensional LiDAR point cloud data is presented. By computing statistics for the entire point cloud along with the implementation of moving window and polynomial fit approaches, empirical relationships were determined that allow the point cloud to estimate surface roughness parameters. A multi-variate regression approach was chosen to investigate the relationship(s) between the predictor variables (LiDAR statistics) and the response variables (surface roughness parameters). It was shown that the empirical fit is weak when comparing the surface roughness parameters to the LiDAR data. The fit was improved by comparing the LiDAR to the more directly measured source terms of the equations used to compute the surface roughness parameters. Future work will involve using these empirical relationships to parameterize a model in the northern Gulf of Mexico and comparing the hydrodynamic results to those of the same model parameterized using contemporary methods. In conclusion, through the work presented herein, it was demonstrated that incorporating remotely sensed data into coastal models provides many benefits including more accurate topobathy descriptions, the potential to provide more accurate surface roughness parameterizations, and more insightful performance assessments. All of these conclusions were achieved using data that is readily available to the scientific community and, with the exception of the Synthetic Aperture Radar (SAR) from the Radarsat-1 project used in the inundation detection method, are available free of charge. Airborne LiDAR data are extremely rich sources of information about the terrain that can be exploited in the context of coastal modeling. The data can be used to construct digital terrain models (DTMs), assist in the analysis of satellite remote sensing data, and describe the roughness of the landscape thereby maximizing the cost effectiveness of the data acquisition.
Show less
Date Issued
2012
Identifier
CFE0004271, ucf:49506
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0004271