Scope and Purpose
The Chesapeake Bay Program integrated models include simulations of the airshed, watershed, estuary, living resources, and climate change. These integrated models assess effects of current and proposed watershed management on changes in nutrient and sediment loads delivered to the Bay, and the effect those changing loads have on water quality and living resources. The CBP Models assist CBP decision-makers in estimating the collective actions needed to achieve State and Federal water quality standards necessary to restore the Bay.
The Modeling Workgroup has a responsibility to the Chesapeake Bay Program Partnership to provide state-of-the-art decision-support modeling tools that are built through community and participatory principles. The responsible planning and management of resources to provide the best available decision-support modeling tools requires the Modeling Workgroup members and participants to adhere to the core values of:
- Integration - Integration of most recent science and knowledge in air, watershed, and coastal waters to support ecosystem modeling for restoration decision making.
- Innovation - Embracing creativity and encouraging improvement in the development and support of transparent and robust modeling tools.
- Independence – Making modeling decisions on the basis of best available evidence and using the most appropriate methods to produce, run, and interpret models, independent of policy considerations.
- Inclusiveness - Commitment to an open and transparent process and the engagement of relevant partners, that results in strengthening the Partnership’s decision making tools.
Overall CBP Model Framework
The CBP model framework is designed to address questions of how Chesapeake Bay water quality will respond to changes in watershed and airshed management actions. In the first step of model scenario development, scenario management actions are interpreted by several models, including the Land Use Change Model, the Airshed Model, and Scenario Builder to produce input to the Watershed Model, as shown in the figure below. The CBP Land Use Change Model, predicts changes in land use, sewerage, and septic systems given changes in land use policy. The Airshed Model, a national application of Community Multiscale Air Quality Model (CMAQ), predicts changes in deposition of inorganic nitrogen due to changes in emissions. The Scenario Builder software combines the output of these models with other data sources, such as the US Census of Agriculture, to generate inputs to the Watershed Model. The Phase 5.3 Watershed Model predicts the loads of nitrogen, phosphorus, and sediment that result from the given inputs.The estuarine Water Quality and Sediment Transport Model (WQSTM) (also known as the Chesapeake Bay Model) predicts changes in Bay water quality due to the changes in input loads provided by the Watershed Model. As a final step, a water quality standard analysis system examines model estimates of DO, chlorophyll, and water clarity to assess in time and space the attainment of the Bay living resource-based water quality standards.
Additional information can be found at:
Projects and Resources
New web page summarizes the priorities and identifies lead researchers for each effort. The descriptions are brief with links to more detailed workplans.
Phase 7 Model Development
The Chesapeake Bay Program is updating its modeling and analysis tools used in the Chesapeake Bay TMDL. For more information, please visit the Phase 7 Model Development Webpage.
The Chesapeake Bay Program and its partners produce tributary basin summary reports for the Bay’s 12 major tributaries using tidal monitoring data from more than 130 monitoring stations throughout the mainstem and tidal portions of the Bay. These reports use water quality sample data to summarize 1) How tidal water quality (TN, TP, DO, Chlorophyll a, Secchi Depth) has changed over time, 2) How and which factors may influence water quality change over time, and 3) Recent research connecting observed changes in aquatic conditions to its drivers.
These documents can be found on the CAST webpage here.
Phase 6 Climate Change Modeling Documentation
- Climate Change Phase 6 Modeling Documentation (pdf - 12.878 MB)
Phase 6 Watershed Model Documentation
The Final Chesapeake Bay Program Partnership Phase 6 CAST and Watershed Model documentation is posted as it becomes available. The documentation is for the time-averaged Watershed Model. CAST is the same as the Model. Creating and running scenarios in CAST is simply using an on-line interface to the Model. The documentation for the Model is the documentation for CAST. Due to the length of the documentation, it is divided into sections. Click on the links below to read through the different portions of the documentation. For more information, please vist CAST model documentation.
8. Direct Loads
10. River to Bay and Temporal Simulation
Appendix 10A: Ftables and Stations
Appendix 10B: Calibration Stations
Appendix 10C: Nutrients and Sediment Calibration Targets
Appendix 10D: HSPF River Water Quality Parameters
Appendix 10E: Estuarine Model Linkage
Cerco, C.F. 2022. "Featured Collection introduction: Climate change in Chesapeake Bay." Journal of the American Water Resources Association 58 (6): 785–789. DOI: 10.1111/1752-1688.13087.View details
Cerco, C.F. 2022. "Dedication to James J. Fitzpatrick" Journal of the American Water Resources Association 58 (6): 790-791. DOI: 10.1111/1752-1688.13088.View details
Bertani, I., G. Bhatt, G.W. Shenk, and L.C. Linker. 2022. "Quantifying the Response of Nitrogen Speciation to Hydrology in the Chesapeake Bay Watershed Using a Multilevel Modeling Approach." Journal of the American Water Resources Association 58 (6): 792–804. https://doi.org/10.1111/1752-1...View details
Workgroups and Action Teams
Dave Montali (Chair), Tetra Tech
Mark Bennett (Chair), U.S. Geological Survey (USGS)
Lewis Linker (Coordinator), Modeling Coordinator, U.S. Environmental Protection Agency
Alex Gunnerson (Staffer), Scientific, Technical Assessment, and Reporting Team Staffer, Chesapeake Research Consortium
1750 Forest Drive Suite 130
Annapolis, Maryland 21401
Bill Keeling, Virginia Department of Environmental Quality
Gary Shenk, Hydrologist, U.S. Geological Survey (USGS)
Peter Tango, Monitoring Coordinator, U.S. Geological Survey (USGS)
George Onyullo, District of Columbia Department of Energy & Environment (DOEE)
1200 First St. NE
Washington, Districtofcolumbia 20002
Ted Tesler, Pennsylvania Department of Environmental Protection
Jesse Bash, U.S. Environmental Protection Agency
Durham, Northcarolina 27709
Karl Berger, Metropolitan Washington Council of Governments
777 North Capitol Street, NE
Washington, Districtofcolumbia 20002
Cassie Davis, New York State Department of Environmental Conservation
Mukhtar Ibrahim, Metropolitan Washington Council of Governments
777 North Capitol St NE #300
Washington, Districtofcolumbia 20002
Bill Ball, Chesapeake Research Consortium
242 Garland Hall
Baltimore, Maryland 21218
Carl Cerco, U.S. Army Corps of Engineers (USACE)
3909 Halls Ferry Road
Vicksburg, Mississippi 39180
Dinorah Dalmasy, Maryland Department of the Environment
Raleigh Hood, University of Maryland Center for Environmental Science
Carl Friedrichs, Virginia Institute of Marine Science (VIMS)
Rt. 1208 Greate Rd.
Gloucester point, Virginia 23062-1346
Hassan Mirsajadi, Delaware Department of Natural Resources and Environmental Control
89 Kings Hwy
Dover, Delaware 19901
Bill Brown, Commonwealth of Pennsylvania
400 Market Stree
Harrisburg, Pennsylvania 17105