The Coastal Modeling System (CMS) is a suite of coupled 2D numerical models for simulating nearshore waves, currents, water levels, sediment transport, morphology change, and salinity and temperature. Developed by the Coastal Inlets Research Program of the US Army Corps of Engineers, the CMS provides coastal engineers and scientists a PC-based, easy-to-use, accurate, and efficient tool for understanding of coastal processes and for designing and managing of coastal inlets research, navigation projects, and sediment exchange between inlets and adjacent beaches. The present technical report acts as a user guide for the CMS, which contains comprehensive information on model theory, model setup, and model features. The detailed descriptions include creation of a new project, configuration of model grid, various types of boundary conditions, representation of coastal structures, numerical methods, and coupled simulations of waves, hydrodynamics, and sediment transport. Pre- and post-model data processing and CMS modeling procedures are also described through operation within a graphic user interface—the Surface- water Modeling System.

Increasing societal pressures (e.g., population growth and urbanization) are driving land use change practices in coastal areas that could potentially alter the hydrodynamics and sediment transport patterns near coastal inlets in ways that might exacerbate existing shoaling conditions. To investigate the potential impact of coastal development, a numerical model is used to predict the long-term evolution of an idealized lagoonal-type barrier island inlet under five different morphological conditions that transitioned from net sediment import to net sediment export. The simulations were designed to address the potential effect of inter-tidal placement and land reclamation on sediment transport and the resulting deposition/erosion patterns. Estuaries that were deeper and devoid of extensive tidal flats tended to promote sediment import and had a greater propensity to exacerbate channel shoaling. Simulations that were characteristic of inter-tidal placement showed net export, yet the likelihood of channel shoaling was increased because some of the material eroded from the tidal flats was deposited in the deeper channels as opposed to being carried out the inlet throat. Alternatively, it was found that regions in which the intertidal area was restricted to elevations higher in the tidal frame, which also showed a net export, produced greater sediment loss in the inter-tidal zone that tended to bypass the deeper sections, reducing the likelihood of channel shoaling.

This is the first part of a two-part report that revisits and updates the verification and validation (V&V) of the Coastal Modeling System (CMS). The V&V study in this part of the report focuses on hydrodynamic and wave modeling. With the updated CMS code (Version 5) and its latest graphical user interface, the Surface-water Modeling System (Version 13), the goal of this study is to revisit some early CMS V&V cases and assess some new cases on model performance in coastal applications. The V&V process includes the comparison and evaluation of the CMS output against analytical solutions, laboratory experiments in prototype cases, and field cases in and around coastal inlets and navigation projects. The V&V results prove that the basic physics incorporated are represented well, the computational algorithms implemented are accurate, and the coastal processes are reproduced well. This report provides the detailed descriptions of those test simulations, which include the model configuration, the selection of model parameters, the determination of model forcing, and the quantitative assessment of the model and data comparisons. It is to be hoped that, through the V&V process, the CMS users will better understand the model’s capability and limitation as a tool to solve real-world problems.

Nearshore nourishments are constructed for shoreline protection from waves, to provide sediment nourishment to the beach profile, and to beneficially use dredged sediment from navigation channel maintenance. However, it is poorly understood how placement morphology and depth influence nearshore processes operated on wave-dominated coasts. This study investigates the wave fields, sediment transport, and morphological response to three common nearshore nourishment shapes, nearshore berm (elongated bar), undulated nearshore berm, and small discrete mounds, with numerical experiments utilizing the Coastal Modeling System. The nourishments are placed in depths between 3 m and 7 m with a volume of approximately 100,000 m3 and between 400 m and 1000 m in alongshore length. Numerical experiments are carried out in three distinct coastal settings with representative wave climates and geomorphology. Simulation results indicate that shallower, more continuous berms attenuate the most wave energy, while deeper, more diffuse placements retain more sediment. Results from this study improve the understanding of nearshore nourishment shapes and can support decision makers identifying the most appropriate construction technique for future nearshore nourishment projects.

INTRODUCTION: Increasing atmospheric concentrations of greenhouse gases are warming the atmosphere and oceans. The global warming and the rise in ocean temperature may gradually increase ocean volume and change sea level (Figure 1) (IPCC 2014). Potential global sea level rise (SLR) combined with coastal storms can drastically change the depth of navigation channels and introduce sediment into navigation channels through adjacent shore erosion. Recognizing the impacts of global climate change with potential SLR on coastal and estuarine waterways, measures need to be taken to assess risk and vulnerability of navigation projects, to conduct research and development that support a reduction of future operation and maintenance costs, and to develop adaptation strategies and management plans to support operations and maintenance practice (USACE 2011).

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 report documents a numerical modeling study investigating sediment transport and morphology change adjacent to Merrimack Inlet, Newburyport, and nearshore in the vicinity of Salisbury Beach and Plum Island, Massachusetts. Concerns at the site include beach erosion, shoreline retreat on Plum Island downdrift of and within the inlet, and reduced navigability of the inlet. The numerical modeling evaluation consists of two phases. The Phase I study was conducted with the damaged and partially rehabilitated South Jetty between 2012 and 2014, and the Phase II study was conducted with the fully rehabilitated South Jetty between 2015 and 2016. Historical hydrodynamic and sediment data in the study area were assembled, and a field data collection program was carried out. The datasets were used to develop a coastal wave, hydrodynamic, and sediment transport model. Different alternatives were developed to evaluate sediment management strategy and structure modification, and the calculated bed sediment volume changes of each alternative were compared with the results under base (existing) condition. Alternative simulations demonstrated the Coastal Modeling System capability in evaluating beach erosion, structure performance, sediment transport, and morphology change in the inlet and estuarine system. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR. ERDC/CHL TR-18-7 iii

A robust method for computing the bed shear stress in unstratified combined wave and current flows is presented.The present approach follows from existing theories describing the nonlinear wave and current interaction in the benthic boundary layer but is designed for arbitrary wave, current, and roughness conditions, including the limiting case of pure waves or pure currents.The stress model is intended as a stand-alone application or for coupling to three-dimensional shelf circulation models, where a broad range of flow conditions are encountered.High-quality data for combined flows and pure waves are used with the present stress formulation to better refine empirical model closure constants in the fully rough turbulent regime.Introducing a first-order correction to the definition of the wave boundary layer thickness produces accurate estimates of both the measured friction factor and wave boundary layer height.A speed of convergence test indicates that the present model is more efficient than previous models that use the same turbulent closure scheme.This is primarily due to an improved solution algorithm that avoids the nested iterations common to established combined wave and current bottom boundary layer models.

This Coastal and Hydraulics Engineering Technical Note (CHETN) describes procedures to calculate temperature change within the Coastal Modeling System (CMS) operated in the Surface-water Modeling System (SMS), version 12.1 (Aquaveo 2010).The defined procedures are demonstrated in an application of temperature modeling in the Corrotoman River, Virginia. INTRODUCTION:Water temperature is an important physical property influencing environmental conditions in aquatic systems.Its value changes with atmospheric conditions, typically ranging from close to 0 ºC in the polar regions to more than 30 ºC in tropical regions.In coastal zones and estuaries, both temporal and spatial variations in water temperature are also controlled by changes in circulation, tide, wind, and freshwater inflows.These changes in temperature can have major effects on water density and water stratification, which can change ocean mixing and modify circulation patterns.Dynamic behavior of suspended sediment can be controlled by the density-driven flow and mixing.Temperature can alter the water physical environment that impacts marine organisms with the change of water turbidity in coastal and estuarine systems.Water quality and ecological models often require input of water temperature and salinity information from a hydrodynamic model. COASTAL MODELING SYSTEM (CMS):The CMS calculates water levels, currents, and waves through the coupling between a hydrodynamic model (CMS-Flow) and a wave model (CMS-Wave).These two models can be coupled to simulate sediment transport, morphology change, and salinity transport (Lin et al. 2008; Sanchez et al. 2014;Li et al. 2012).CMS-Flow is a two-dimensional (2D), finite-volume model that solves the mass conservation and momentum equations of shallow water motion.CMS-Flow is forced by water surface elevation (WSE) (e.g., from tide) and river discharge at model boundaries, wave radiation stress, and wind forcing over a model computational domain.Physical processes calculated by CMS-Flow include wave-current interaction, sediment transport, morphology change, and salinity transport.CMS-Wave is a 2D, quasi-steady spectral wave transformation model.The model contains theoretically derived approximations of wave diffraction, reflection, and wavecurrent interactions for wave simulations at coastal inlets with jetties and breakwaters.

The primary focus of this study is to apply a two-dimensional (2-D) coupled flow-wave-sediment modeling system to simulate the development and growth of idealized barrier island tidal inlets. The idealized systems are drawn from nine U.S. coastal inlets representing Pacific Coast, Gulf Coast and Atlantic Coast geographical and climatological environments. A morphological factor is used to effectively model 100 years of inlet evolution and the resulting morphological state is gauged in terms of the driving hydrodynamic processes. Overall, the model performs within the range of established theoretically predicted inlet cross-sectional area. The model compares favorably to theoretical models of maximum inlet currents, which serve as a measure of inlet stability. Major morphological differences are linked to inlet geometry and tidal forcing. Narrower inlets develop channels that are more aligned with the inlet axis while wider inlets develop channels that appear as immature braided channel networks similar to tidal flats in regions with abundant sediment supply. Ebb shoals with strong tidal forcing extend further from shore and spread laterally, promoting multi-lobe development bisected by ebb shoal channels. Ebb shoals with moderate tidal forcing form crescent bars bracketing a single shore-normal channel. Longshore transport contributes to ebb shoal asymmetry and provides bed material to help maintain the sediment balance in the bay.

Coastal Sediments 2015 (2015) No AccessLONG-TERM MORPHOLOGICAL MODELING AT COASTAL INLETSALEJANDRO SANCHEZ, MITCHELL BROWN, TANYA BECK, RICHARD STYLES and HONGHAI LIALEJANDRO SANCHEZU.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USA, MITCHELL BROWNU.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USA, TANYA BECKU.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USA, RICHARD STYLESU.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USA and HONGHAI LIU.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USAhttps://doi.org/10.1142/9789814689977_0214Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: The U.S. Army Corps of Engineers' Coastal Modeling System (CMS) is used to simulate the long-term morphodynamics of coastal barrier-inlet systems. The CMS consists of an integrated numerical modeling system for simulating wave, current, water levels, sediment transport and morphology change. In order to quantify the physical effects of long-term, regional climactic changes in the environment, numerical morphodynamic models must be able to reproduce the known generic characteristics that drive barrier inlet processes, including equilibrium inlet dimensions and sediment budget for the tidal shoals. In this study, model results are presented for a 10-year simulation of an idealized inlet and bay system with dimensions similar to that of Humboldt Bay, CA. The model reproduces reasonably well several geomorphic and hydrodynamic features of the inlet at Humboldt Bay. The model results demonstrate the feasibility of applying the CMS for simulating long-term morphology at coastal inlets for practical applications. FiguresReferencesRelatedDetails Coastal Sediments 2015Metrics History PDF download

: 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.

The US Army Engineer District, San Francisco (SPN) and the Coastal Inlets Research Program conducted a pilot study to consider various placement locations for dredged material in vicinity of Noyo Harbor, CA.Approximately 30,000-40,000 cu yd/yr of beach-quality sediment is dredged from the navigation channel and the lower Noyo River, located on the north

: This paper describes the numerical modeling of nearshore placement of dredged material at Noyo Harbor, CA. The numerical models include the US Army Corps of Engineers (USACE) Short-Term FATE model (STFATE), Coastal Modeling System (CMS), and Particle Tracking Model (PTM). The STFATE simulates the spatial distribution of dredged material in open water after it has passed through the water column on release of the barge load. The CMS calculates wave transformation, flow circulation, water levels, sediment transport, and morphology change. The modeling provides technical information necessary to evaluate a location site that is economically feasible for the optimum sediment placement. The model simulation showed small onshore sediment transport in typical summer and winter months. The calculated fine sediment transport during the dredged material release at the placement site indicated more longshore movement as the result of strong wind driven current along the coast.

: Damon Point in Grays Harbor has experienced continued evolution towards the existing navigation channel and the land intrusion into the harbor posts potential threat to navigation and port operation. Numerical modeling study was conducted to investigate the hydrodynamics, sediment transport, and morphology change at the harbor near the navigation channel. Calculated waves, currents, water levels, sediment transport and long term morphology changes were calibrated and validated with the field measurements. Hydrodynamic and morphodynamic analysis indicates that sediment transport due to the land evolution will not result in significant depth changes in the nearby channel in the next 5 years.