This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the use of the Dredging Module (DM) with multiple grain-size sediment transport within the U.S. Army Corps of Engineers (USACE) Coastal Modeling System (CMS).The DM simulates one or more dredging operations during a CMS simulation and provides options for the

: This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the implementation of a dredging module (DM) within the U.S. Army Corps of Engineers (USACE) Coastal Modeling System (CMS). The DM simulates one or more dredging operations during a CMS simulation and provides options for the dredging and placement of material. The DM may be used in studies such as estimating future dredging requirements, evaluating alternative dredging operations, and analyzing morphologic consequences of dredging operations. A coastal ap-plication at St. Marys Entrance Channel, FL, is provided to illustrate the setup procedure and demonstrate the model capability.

Dana Point Harbor is located on the southern California coast, midway between Los Angeles and San Diego. The harbor is protected by dual semi-permeable breakwaters, the East and the West Breakwaters. The permeability of the breakwaters has been designed to promote circulation and improve water quality in the harbor. However, wave and flow actions have increased sediment movement around the West Breakwater and resulted in harbor channel infilling in recent years. To investigate the sediment transport around the porous breakwater and reduce potential dredging cost in the future, an integrated coastal wave, hydrodynamic and sediment transport numerical model was used to investigate the effect of the permeability of breakwater. First, the model was validated with the field measurements of waves, current, and water surface elevation at two ADCP gages located on the harbor side and the ocean side of the West Breakwater. Further validation in the model’s capability to simulate wave flow through a porous structure was also performed with a laboratory experiment of low-crested structures under regular waves. Wave transmission, flow and sediment around the West Breakwater were calculated for 1-year period of 2009–2010. The calculated annual sediment rate in the inner side of breakwater was comparable to the sediment accumulation rate available from historical dredging records.

Coastal Sediments 2015 (2015) No AccessNUMERICAL MODELING OF MIXED SEDIMENT TRANSPORT IN GIWW AND WEST GALVESTON BAY, TEXASLIHWA LIN and CHRIS W. REEDLIHWA LINUS Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USA and CHRIS W. REEDReed and Reed Consulting, LLC, 1400 Village Square Blvd, Tallahassee, FL 32312, USAhttps://doi.org/10.1142/9789814689977_0145Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: Wave, flow, and sedimentation numerical models in the Coastal Modeling System (CMS) were applied to compute mixed sediment transport at Gulf Intracoastal Waterway (GIWW) and West Galveston Bay along the upper coast of Texas. The models were used to estimate increasing shoaling rates in the GIWW as a result of eroding channel banks and diminishing barrier islands between GIWW and West Galveston Bay by storm surge and waves. The modeling effort included the simulation of daily barge traffic flow in GIWW and evaluated two proposed alternatives to protect channel banks and restore barrier islands. Model results show armoring channel banks and protecting barrier islands will substantially reduce the channel shoaling rates in the region. FiguresReferencesRelatedDetails Coastal Sediments 2015Metrics History PDF download

The increased rate of shoaling in Dana Point Harbor requires a better understanding of hydrodynamics and sediment transport around a permeable breakwater. In this study, an integrated coastal wave, hydrodynamic and sediment transport numerical model was developed to investigate the circulation and sedimentation patterns around the harbor, to address sediment seepage through the permeable West Breakwater, and to assist find solutions to reducing the shoaling inside the harbor. The model calibration and validation were conducted against field measurements of waves, current, and water surface elevation, and a laboratory experiment of low-crested structures (LCS). Comparisons of the calculated results and the measurements indicate that waves are the dominant forcing outside the harbor. Inside the harbor, currents are wind- and tide-driven with small current magnitude of less than 4 cm/sec. The distribution of morphology change shows significant sediment movement and sediment pathways around the West Breakwater. The calculated annual sediment rate in the inner side of the breakwater was comparable to the sediment accumulation rate available from historical dredging records.

: The Coastal Modeling System (CMS) is an integrated numerical modeling system for simulating nearshore waves, currents, water levels, salinity and sediment transport, and morphology change. The CMS was designed and developed for coastal inlets and navigation applications, including channel performance and sediment exchange between inlets and adjacent beaches. The present report provides an updated description of the mathematical formulations and numerical methods of hydrodynamic, salinity and sediment transport, and morphology change model CMS-Flow. The CMS-Flow uses the Finite Volume Method on Cartesian grids and has both fully explicit and fully implicit time stepping schemes. A detailed description of the explicit time stepping scheme was provided in Militello et al. (2004) and Buttolph et al. (2006). The present report focuses on the recent changes in the mathematical formulations, and the implicit time stepping schemes. The CMS-Wave and CMS-Flow models are tightly coupled within a single inline code. The CMS-Wave and CMS-Flow grids may be the same or have different spatial extents and resolutions. The hydrodynamic model includes physical processes such as advection, turbulent mixing, combined wave-current bottom friction; wave mass flux; wind, atmospheric pressure, wave, river, and tidal forcing; Coriolis force; and the influence of coastal structures. The implicit hydrodynamic model is coupled to a nonequilibrium transport model of multiple-sized total-load sediments. The model includes physical processes such as hiding and exposure, bed sorting and gradation, bed slope effects, nonerodible surfaces, and avalanching.

: This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the mathematical formulation, numerical implementation, and input specifications of weir structures in the Coastal Modeling System (CMS) operated through the Surface-water Modeling System (SMS). A coastal application at Rudee Inlet, Virginia is provided to illustrate the implementation procedure and demonstrate the model capability. A weir is an overflow structure built across a river or an open channel, allowing water to flow over the top. Weirs are commonly used for flow and flooding control and salinity and sediment management. Weirs are also constructed as nearshore coastal structures, such as weir jetties, to control longshore sediment transport, stabilize channel morphology, and protect harbors and navigation channels (Figure 1). In coastal applications, weirs represent unique features of solid structures and it is necessary to incorporate the structures into coastal hydrodynamic and sediment transport modeling systems. The CMS, developed by the Coastal Inlets Research Program (CIRP), is an integrated suite of numerical models for simulating water surface elevation, current, waves, sediment transport, and morphology change in coastal and inlet applications. It consists of a hydrodynamic and sediment transport model, CMS-Flow, and a spectral wave model, CMS-Wave (Sanchez et al. 2011a; Sanchez et al. 2011b; Lin et al. 2011). Both are described in Part I of this series (Li et al. 2013).

This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the mathematical formulation, numerical implementation, and input specifications of rubble mound structures in the Coastal Modeling System (CMS) operated through the Surface-water Modeling System (SMS). A coastal application at Dana Point Harbor, California is provided to illustrate the implementation procedure and demonstrate the model capability.

: This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the mathematical formulation and numerical implementation of a culvert in the Coastal Modeling System (CMS) operated through the Surface-water Modeling System (SMS). A coastal application is provided to illustrate the implementation procedure at Poplar Island, MD. Culverts are a common coastal engineering structure typically used in coastal wetlands to control waste and storm water discharges, act as salinity barriers, optimally distribute freshwater, and manage sediment transport (Figure 1). In coastal applications, the culverts often connect open water bodies of similar water surface elevation to enhance flushing or conduct flow through levees or causeways. Since culverts are a significant component of hydrodynamic and sediment transport controls in the coastal zone, it is important that the CMS simulates their effects. The implementation of culverts in the CMS is based on equations developed by Bodhaine (1982). As a validation, the culverts are applied for the hydrodynamic calculations in a wetland application in Chesapeake Bay, Maryland. The CMS, developed by the Coastal Inlets Research Program (CIRP), is an integrated suite of numerical models for simulating water surface elevation, current, waves, sediment transport, and morphology change in coastal and inlet applications. It consists of a hydrodynamic and sediment transport model, CMS-Flow, and a spectral wave model, CMS-Wave (Buttolph et al. 2006; Sanchez et al. 2011a; Sanchez et al. 2011b; Lin et al. 2008). Both are described in Part I of this series (Li et al. 2013).

: This is the third report, Report 3, in a series of four reports toward the Verification, and Validation (V&V) of the Coastal Modeling System (CMS). All details of the V&V study specific to the hydrodynamic modeling are provided in this report. The primary goal of this study task was to perform a comprehensive assessment of the predictive skills of the CMS-Flow model for a wide range of problems encountered in coastal applications, with an emphasis on applications for coastal inlets and navigation projects. The evaluation study began by considering some simple and idealized test cases for checking the basic physics and computational algorithms implemented in the CMS-Flow model. After these fundamental comparisons, the model was evaluated with a large number of test cases representing real world problems. These application-oriented tests were selected carefully and only those which had data available from laboratory and field studies were considered. Included in this report are the descriptions of each test case, model setup, the boundary conditions used for each numerical simulation, and an assessment of the modeling results. Major findings and default parameters are provided as guidance to users for practical applications of CMS-Flow.

The shoreline stabilization adjacent to the public access boat ramp in the Packery Channel basin has been damaged in two separate events. For the shoreline damage at the boat ramp bulkhead, toe scour is the likely mechanism for failure. Typical sources of hydrodynamic forcing that can lead to toe erosion include storm currents, locally generated storm waves, and offshore storm waves propagating into the basin through Packery Channel. Quantitative analysis of storm induced wind generated waves and currents eliminated them as possible causes of the damage. However, photographic and movie evidence indicate the presence of low-frequency low-amplitude waves propagated into the basin and impacted the boat ramp. The Coastal System Model (CMS) was used to simulate a range of these low-frequency low-amplitude waves and the results demonstrated that these waves could produce sufficient flows in the vicinity of the boat ramp shoreline to cause the damage. Subsequent modeling was used to develop design criteria for additional shoreline stabilization.

CMS-Flow is a coupled time-dependent circulation, sediment transport and morphodynamic model based on the numerical solution of the mass, momentum and transport equations on a Cartesian (quad-tree) grid network with both explicit and implicit solvers. It has been developed and is currently supported under the Coastal Inlets Research Program (CIRP) conducted at the U.S. Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL). The model's primary function is to support multi-disciplinary research teams and conduct practical projects at coastal inlets. CMS-Flow has been designed with a relatively simple code structure which allows for rapid development and inclusion of new sediment transport algorithms, while always being accessible to the general modeling community, including both USACE and commercial users. Today, CMS-Flow is an integral component of the CIRP, providing technology for simulating hydrodynamics, waves, sediment transport and morphology for short and long timeframes in coastal inlets, adjacent beaches, navigation channels and bays.

Following the extreme flooding caused by Hurricane Katrina, the Federal Emergency Management Agency (FEMA) commissioned a study to update the Mississippi coastal flood hazard maps. The project included development and application of new methods incorporating the most recent advances in numerical modeling of storms and coastal hydrodynamics, analysis of the storm climatology, and flood hazard evaluation. This paper discusses the methods that were used and how they were applied to the coast of the State of Mississippi.

The Joint Probability Method (JPM) has been used for hurricane surge frequency analysis for over three decades, and remains the method of choice owing to the limitations of more direct historical methods. However, use of the JPM approach in conjunction with the modern generation of complex high-resolution numerical models (used to describe winds, waves, and surge) has become highly inefficient, owing to the large number of costly storm simulations that are typically required. This paper describes a new approach to the selection of the storm simulation set that permits reduction of the JPM computational effort by about an order of magnitude (compared to a more conventional approach) while maintaining good accuracy. The method uses an integration scheme called Bayesian or Gaussian-process quadrature (together with conventional integration methods) to evaluate the multi-dimensional joint probability integral over the space of storm parameters (pressure, radius, speed, heading, and any others found to be important) as a weighted summation over a relatively small set of optimally selected nodes (synthetic storms). Examples of an application of the method are shown, drawn from the recent post-Katrina study of coastal Mississippi.

Similar submarine canyon systems exist on scales ranging from less than a kilometer to nearly 1000 km. The shallowest end is a submarine canyon and canyon head(s). Further down the canyon is buried by the upper part of a submarine fan with meandering and cross-cutting channels. The fan eventually merges with a nearly flat-lying depositional basin. We have used the deposits associated with these common morphological features to calibrate and verify numerical models. When model parameters are correctly set the characteristic variations of the sediment grain size distributions and bed thicknesses predicted by the model should match patterns observed in cores. This study examines the relationship between the scale of canyon systems created and characteristics of the depositional zones using idealized morphologies. The 2-DV numerical model tracks 5 grain sizes, includes bedload and pelagic sedimentation. One set of experiments represents large systems with long-duration source events. The idealized large system is a composite of the Amazon, Monterey and Congo Canyons. The smaller system represents the submarine canyons along the north central Gulf of Mexico. The modeling shows that deposits in large systems develop as the result of several episodes of reworking by a sequence of turbidity current events. In the upper reaches of the canyon and fan the pattern of grain size sorting is highly variable according to the magnitude of the triggering event. This leads to a distinctive pattern of core layers which show many truncated beds. This pattern is much more subdued in the smaller system because reworking is less intense. Both of these patterns show a strong dependence on the characteristics of the source event and it frequency of occurrence.