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Model Report


Last Revision Date: 08/31/2009 View as PDF
General Information Back to Top
Model Abbreviated Name:

Model Extended Name:

Model Overview/Abstract:
CE-QUAL-ICM was designed to be a flexible, widely-applicable eutrophication model. The model operates in one- two- or three-dimensional configurations and incorporates twenty-seven state variables including physical properties; multiple forms of algae, zooplankton, carbon, nitrogen, phosphorus, and silica; dissolved oxygen; and a pathogen and two toxicants. Sediment-water oxygen and nutrient fluxes may be computed in a predictive submodel or specified based on observations. Living-resource modules include submerged aquatic vegetation, benthic filter feeders, and benthic deposit feeders.

Keywords: Ecosystem modeling, Water quality modeling, Living resources, Nutrient analysis, Eutrophication, Submerged aquatic vegetation, Chesapeake Bay
Model Technical Contact Information:
EPA Contact:
Lewis C. Linker
Modeling Coordinator
Chesapeake Bay Program Office
410 Severn Avenue
Annapolis, MD 21403

Developer Contact
Carl F. Cerco
Army Corps of Engineers (Mail Stop: EP-W)
(601) 634-4207

The model was developed and is maintained by Carl Cerco.

Model Homepage: http://el.erdc.usace.army.mil/elmodels/icminfo.html Exiting the EPA Site
Substantive Changes from Prior Version: Quantitative modeling of living resources including submerged aquatic vegetation, deposit-feeding benthos, filter-feeding benthos. Code parallelized using MPI.
Plans for further model development: Incorporation of dynamic sediment transport underway.

User Information Back to Top
Technical Requirements
Computer Hardware
Windows 95, 98, NT, or later UNIX or LINUX
Compatible Operating Systems
Other Software Required to Run the Model
The model contains a sub-module for sediment diagenesis and aquatic vegetation.
Download Information
Using the Model
Basic Model Inputs
Model requires definition of a computational grid. Hydrodynamics consistent with the grid must be provided. External loads and boundary conditions must be specified.
Basic Model Outputs
Concentrations of state variables. Biomass of living resources. Computed fluxes between state variables. Mass transport between model cells.
User Support
User's Guide Available?
Provides: (1) an abstract or abstract equivalent in the introduction, (2) schematic/diagram showing model structure and interaction of model components, (3) equations, equation solution methodologies, and related simplifying assumptions, (4) example input/output files, (5) input and output variable documentation including definitions, units, temporal/spatial dimensions, temporal/spatial resolution options, and (if applicable such as with FORTRAN) format, and (6) guidance on selecting and/or estimating values and/or distributions for input variables (including guidance on calibration and selecting default values and/or distributions).

Available at:

User Qualifications
User needs high level of technical education and/or modeling experience.

Model Science Back to Top
Problem Identification
The model was initially developed to address abatement of hypoxia in Chesapeake Bay via nutrient load reductions. Subsequent developments led to quantitative modeling of living resources and their interactions with the environment. The model has been widely applied in lakes, estuaries and coastal waters in a variety of climates. Most studies have been aimed at improving water quality via reductions in nutrient and solids loads. Lately, the model has been employed to examine alternatives to load reductions such as restoration of filter-feeding organisms.
Summary of Model Structure and Methods
The model is an integrated-compartment model now often referred to as a finite-volume model. The model is based on the three-dimensional conservation of mass equation solved via the finite-difference method on an unstructured computational grid. The QUICKEST method is used in the longitudinal and lateral directions. Vertical solution is via a Crank-Nicolson scheme. Time steps are on the order of minutes.
Model Evaluation
The code has been extensively verified against numerous analytical solutions. These tests have not been published. Every model application is compared to field data. A sampling of these comparisons can be found in the following reports and papers:

Cerco, C., and Cole, T. (1993). “Three-dimensional eutrophication model of Chesapeake Bay,” Journal of Environmental Engineering, 119(6), 1006-1025.

Cerco, C., Bunch, B., Dortch, M., Johnson, B., and Kim, K. (2003). “Eutrophication and pathogen abatement in the San Juan Bay Estuary,” Journal of Environmental Engineering, 129(4), 318-327.

Cerco, C., Noel, M., and Kim, S-C. (2006). “Three-Dimensional Management Model for Lake Washington: (II) Eutrophication Modeling and Skill Assessment,” Journal of Lake and Reservoir Management, 22(2), 115-131.

Tillman, D., Cerco, C., Noel, M., Martin, J., and Hamrick, J. (2004). “Three-dimensional eutrophication model of the Lower St. Johns River, Florida,” ERDC/EL TR-0413, US Army Engineer Research and Development Center, Vicksburg MS.

Key Limitations to Model Scope
The model does not compute hydrodynamics. Flows, diffusion coefficients, and volumes must be specified externally and read into the model. Hydrodynamics are usually obtained from a hydrodynamics model such as the CH3D-WES model. The user must provide processors that prepare input files and process output for presentation.

Case Studies
Cerco, C., Bunch, B., Dortch, M., Johnson, B., and Kim, K. (2003). “Eutrophication and pathogen abatement in the San Juan Bay Estuary,” Journal of Environmental Engineering, 129(4), 318-327.

Cerco, C., and Noel, M. (2004). “Managing for water clarity in Chesapeake Bay,” Journal of Environmental Engineering, 130(6), 631-642.

Cerco, C., Bunch, B., and Letter, J. (1999). “Impact of a flood-diversion tunnel on Newark Bay and adjacent waters, Journal of Hydraulic Engineering, 125(4), 328-338.

Cerco, C., and Meyers, M. (2000). “Tributary refinements to the Chesapeake Bay Model,” Journal of Environmental Engineering, 126(2), 164-174.

Cerco, C., and Moore, K. (2001). “System-wide submerged aquatic vegetation model for Chesapeake Bay,” Estuaries, 24(4), 522-534.

Cerco, C. (1995). “Response of Chesapeake Bay to nutrient load reductions,” Journal of Environmental Engineering, 121(8), 549-557.

Cerco, C., Linker, L., Sweney, J., Shenk, G., and Butt, A. (2002). “Nutrient and solids controls in Virginia’s Chesapeake Bay tributaries,” Journal of Water Resources Planning and Management, 128(3), 179-189.

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