| Prediction and Assimilation of Surf-zone Processes using a Bayesian Network. Part I: Forward Models |
03 Sep 2010 |
14 pages |
| Authors:
Nathaniel G Plant; K T Holland; GEOLOGICAL SURVEY SAINT PETERSBURG FL
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 | Prediction of coastal processes, including waves, currents, and sediment transport, can be obtained from a variety of detailed eophysical-process models with many simulations showing significant skill. This capability supports a wide range of research and applied efforts that can benefit from accurate numerical predictions. However, the predictions are only as accurate as the data used to drive the models and, given the large temporal and spatial variability of the surf ... |
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| The Coastal Dynamics of Heterogeneous Sedimentary Environments: Numerical Modeling of Hydrodynamics and Mass Transport in Estuaries |
12 Aug 2010 |
139 pages |
| Authors:
Timothy R Keen; K T Holland; NAVAL RESEARCH LAB WASHINGTON DC OCEANOGRAPHY DIV
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| This report discusses details of the numerical algorithms used to simulate wave, tide, and wind-driven hydrodynamics in estuaries and coastal bays. The impacts of the predicted flow on mass transport in estuaries are examined. The results of several sample problems are presented and compared to observations where possible. The results are intended to be used as guidance in formulating modeling strategies for different coastal environments and specific applications. |
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| The Coastal Dynamics of Heterogeneous Sedimentary Environments: Numerical Modeling of Nearshore Hydrodynamics and Sediment Transport |
10 May 2010 |
145 pages |
| Authors:
Timothy R Keen; K T Holland; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
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| This report discusses details of the numerical models used to simulate wave, tide, and wind-driven hydrodynamics and sedimentation in water depths less than 10 m. These simulations have used the Princeton Ocean Model (POM), the Navy Coastal Ocean Model (NCOM), the SWAN wave model, and the Littoral Sedimentation and Optics Model (LSOM). The problems include: (1) nearshore erosion and mass conservation on the shoreface; (2) coastal erosion during a hurricane; ... |
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| Sensitivity of Delft3D to Input Conditions |
15 Jan 2010 |
9 pages |
| Authors:
Kacey L Edwards; Jayaram Veeramony; David Wang; K T Holland; Yuan-Huang L Hsu; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| In January 2009, the forecasting ability of the Delft3D modeling suite was demonstrated in real time for an area in the Northern Gulf of Mexico. As part of the demonstration, a bathymetric survey was conducted, and several wave buoys of different types were deployed. Delft3D is a three-dimensional modeling suite that can also be run in depth-averaged mode to provide wave conditions, currents, changes in morphology, or a combination of ... |
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| Littoral Environmental Reconnaissance Using Tactical Imagery From Unmanned Aircraft Systems |
Jan 2010 |
9 pages |
| Authors:
K T Holland; David M Lalejini; Steven D Spansel; Robert A Holman; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
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| The dynamic nature of littoral regions requires a reconnaissance approach that can rapidly quantify environmental conditions. Inadequate estimation of these conditions can have substantial impacts on the performance of Naval systems. Given that expeditionary warfare operations can occur over timescales on the order of hours, exploitation of video imagery from tactical vehicles such as Unmanned Aircraft Systems (UAS) has proved to be a reliable and adaptive solution. Tactical littoral products ... |
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| Characterization of a Mud Deposit Offshore of the Patos Lagoon, Southern Brazil |
Feb-2009 |
13 pages |
| Authors:
Allen H Reed; Richard W Faas; Mead A Allison; Lauro J Calliari; K T Holland; S E O'Reilly; W C Vaughan; A Alves; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOACOUSTICS DIV
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| Rapid deposition of mud on the beach along the shoreface of Rio Grande do Sul, Brazil dramatically influences the normal operations in the littoral zone. In the surf zone, fluid and suspended mud opposes water-wave movement and dissipates water-wave energy; on the beach, mud limits trafficability. As part of a multinational, multidisciplinary program to evaluate the influence of mud strength, density and viscosity on water-wave attenuation, sediments were evaluated in ... |
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| A Study of Dissipation of Wind-Waves by Mud as Cassino Beach, Brazil: Prediction and Inversion |
Jan-2009 |
16 pages |
| Authors:
W E Rogers; K T Holland; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| The impact of a non-rigid seafloor on the wave climate at Cassino Beach, Brazil, May-June 2005 is studied using field measurements and a numerical wavemodel. The measurements consist of wave data at four locations; rheology and mud thickness from grab samples; and an estimate of the horizontal distribution of mud based on echo-soundings. The dissipation of waves by a non-rigid bottom is represented in the wave model by treating the ... |
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| Thermal Diffusivity and Strength of Tidal Flat Sediments During a Tidal Simulation |
Jan 2009 |
6 pages |
| Authors:
Allen H Reed; Jennifer L Miselis; K T Holland; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
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| Coastal margins and tidal flat sediment systems are some of the most complex, heterogeneous and energetically dynamic regions on earth. Tidal flats are repositories of terrigenous and biogenous sediments that are shaped by tides, waves and storms and utilized by birds and benthic organisms. They often lie adjacent to rivers that enable inland passage for ships and access to spawning grounds for fish. As such, they are subject to numerous ... |
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| Littoral Battlespace Characterization Using Small Unmanned Aerial Systems |
Jan 2009 |
2 pages |
| Authors:
K T Holland; D Lalejini; K Plavnick; NAVAL RESEARCH LAB WASHINGTON DC MARINE GEOSCIENCES DIV
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| Few environmental regions are as dynamic as the littoral, where dramatic changes in winds, waves, and bathymetry can occur over timescales as short as a few hours. A long-term goal for the Littoral Dynamics Team within the Naval Research Laboratory (NRL) is to extract littoral meteorological and oceanographic (METOC) conditions from intelligence, surveillance, and reconnaissance (ISR) imagery collected by either space or airborne platforms in near real time. Our most ... |
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| The Effect of Bathymetric Filtering on Nearshore Process Model Results |
Jan 2009 |
11 pages |
| Authors:
Nathiel G Plant; Kacey L Edwards; James M Kaihatu; Jayaram Veeramony; Larry Hsu; K T Holland; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| Nearshore wave and flow model results are shown to exhibit a strong sensitivity to the resolution of the input bathymetry. In this analysis, bathymetric resolution was varied by applying smoothing filters lo high-resolution survey data to produce a number of bathymetric grid surfaces. We demonstrate that the sensitivity of model-predicted wave height and flow to variations in bathymetric resolution had different characteristics. Wave height predictions were most sensitive to resolution ... |
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| Behavior of a Large Cylinder in Free-Fall Through Water |
Jan-2007 |
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| Authors:
K T Holland; Andrei V Abelev; Philip J Valent; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOACOUSTICS DIV
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 | This paper presents results of experimental deployment of a large instrumented cylinder of variable nose geometry and center of mass offset (CMO) in free-fall in realistic environment. Data on four tests series in the Gulf of Mexico are presented and analyzed statistically. The stochastic nature of the problem of the cylinder free-falling through water is outlined and described as an input to the subsequent impact burial prediction package. Significance of ... |
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| Discrete Particle Model for Surf Zone Sediment Transport |
Jan 2005 |
4 pages |
| Authors:
J Calantoni; K T Holland; T G Drake; NAVAL RESEARCH LAB WASHINGTON DC MARINE GEOSCIENCES DIV
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| Sediment transport in nearshore wave bottom boundary layers drives coastal geomorphologic change and can result in bathymetric changes of more than a meter in as little as a few hours, particularly in the region where waves are breaking. Predicting the evolution of surf zone bathymetry is of significant importance, with economic, legal, engineering, scientific, and military implications. Most formulae for predicting sediment transport in surf zone subsume the smallest scale ... |
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