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Numerical Modeling of Coastal Physical Processes

The Coastal Modeling System (CMS) is a suite of coupled two-dimensional (2D) numerical models for simulating waves, hydrodynamics, salinity and sediment transport, and morphology change.  Developed by the Coastal Inlets Research Program (CIRP) of the ERDC Coastal & Hydraulics Laboratory (CHL), the CMS provides coastal engineers and scientists an efficient tool for understanding coastal processes and for designing and managing of coastal inlets, navigation channels, ports, harbors, coastal structures and adjacent beaches.  The CMS was identified by the USACE Community of Practice (CoP) as a preferred model for Coastal Engineering and Coastal Navigation investigations.

Improved Numerical Modeling for Coastal Engineering and Navigation Projects

The CMS provides coastal engineers and scientists a PC-based, easy-to-use, accurate, and efficient tool to assist in designing and managing coastal engineering and navigation projects by facilitating:

  • Integrated and coupled calculations of waves, currents, water levels, sediment transport and morphology change in and around inlets, ports and harbors, and associated navigation channels and coastal structures such as jetties, breakwaters, groins and seawalls
  • High resolution short- (weeks) to mid-term (seasonal to multiple years) project scale simulations
  • Representation of a wide range of nearshore physical processes, such as wetting and drying, advection, turbulent mixing, forcing from tides, wind, atmospheric pressure, and waves; river flows, wave-current interaction, multiple-sized sediment transport, bed sorting, and morphology change
  • Representation of weirs, culverts, porous rubble mounds and tidal gates


The CMS consists of a flow model (CMS-Flow) and a wave model (CMS-Wave).  CMS-Flow is a 2D depth-integrated model for simulating wave-averaged hydrodynamics and nonuniform sediment transport and morphology change in coastal waters.  CMS-Flow calculates currents and water levels and includes physical processes such as wetting and drying, advection, wave-enhanced turbulent mixing and bottom friction, forcing from wind, atmospheric pressure, waves, river, tides, and the Coriolis-Stokes force.  CMS-Wave is a 2D, finite-difference spectral wave model and simulates wave generation, transformation, and dissipation. Physical processes calculated in the model include refraction, diffraction, reflection, bottom friction, breaking, waves-current interaction, and structure effects. CMS-Flow and CMS-Wave are tightly coupled and may be run on the same or different computational grids.  The models also support grid nesting within larger domain simulations. CMS is interfaced through the Surface-water Modeling System (SMS).  The CMS is designed for small to medium project scale (order of 1 to 10s of km) applications.  Some key CMS features include:

  • Parallelization on PC computers
  • Support for multiple Cartesian grid types: uniform, non-uniform, telescoping and stretched telescoping
  • User-friendly interface for grid generation, model setup, model results visualization and post-processing

Testing and Applications

The CMS has been verified with 10 analytical cases and validated with 16 field and 14 laboratory datasets covering a wide range of conditions.  Examples of CMS applications include:

  • Navigation channel performance, realignment and sediment exchange between inlets, deposition basins and borrow sites, ports and harbors, and adjacent beaches to reduce navigation operation and maintenance costs
  • Optimization of channel reliability and advanced dredging practices to improve navigation safety
  • Design and rehabilitation of jetties and breakwaters for coastal protection
  • Determination of best dredging and placement options for improved regional sediment management
  • Short- and mid-term implications of engineering activities in the vicinity of coastal navigation channels, such as ebb tidal shoal mining, channel deepening, and jetty modifications

CMS has been applied at more than 70 project sites in the US in seven international project sites. Examples documented in CMS reports include Matagorda Bay, Texas; Grays Harbor, Wash.; Mouth of the Columbia River, Wash./Ore.; Ocean Beach, Calif.; Southeast Oahu Coast, Hawaii; Field Research Facility, Duck, N.C; Hazaki Oceanographic Research Facility, Japan; Mississippi Sound and Barrier Islands; Gironde Estuary, France; St. Augustine Inlet, Fla.; and Shark River Inlet, N.J.

Cost and Distribution

The CMS is available for free from the CMS Release Page, can be run as a stand-alone executable, and is interfaced and distributed through the Surface-Water Modeling System (SMS).  

Documentation, Training, and Support

CMS help is available through workshops, webinars, on-site traning and several wiki pages. For more information, please visit CIRP online.


ERDC Points of Contact

Questions about CMS?

Julie D. Rosati
Program Manager of CIRP
Email: Julie.D.Rosati@usace.army.mil
Phone: (251) 694-3719 or (202) 761-1850

Honghai Li
CMS Principal Investigator
Email:  Honghai.Li@usace.army.mil  
Phone: (601) 634-2840

beach evolution coastal evolution coastal structures deposition deposition basins dredged-material placement sites erosion estuaries flood tidal shoals harbors infilling inlets jetty/breakwater stability modeling morphodynamics morphologic evolution navigation channel performance ports sediment transport