Phase 6 Watershed Model Development

Chesapeake Bay Phase 6 Watershed Model Development

Background

The Chesapeake Bay Program (CBP), in conjunction with the Bay watershed states, has been working on the development of the Phase 6 version of the Chesapeake Bay Watershed Model (P6 Model).  The P6 Model will be used in the development of the Phase III Chesapeake Bay Watershed Implementation Plans (WIPs).  Data related to the development of the new model is available for download below. Currently, the only item for stakeholders to view is the first draft version (v1) of the P6 land-use.  New items will be added to this page as they are made available by CBP and the State of Maryland.

Model Land-Use (Draft, Version 1)

Following the development of Maryland's Phase II WIP, MDE received comments from several local jurisdictions related to the model land-use estimates.  In order to fully address these concerns, MDE and its partners, Maryland Department of Planning (MDP), Maryland Department of Natural Resources (MD DNR), and CBP, have made it a priority to collect and incorporate the most accurate local land-use/land-cover data into the P6 Model.  For the majority of the State, this meant incorporating the planimetric datasets compiled by the counties. The land-use data sets provided below utilize and build off this data.  MDE and its partner agencies are currently asking for the local jurisdictions to review the data and provide the State with feedback.

Model Land-Use Methods

The State has developed methodologies for incorporating impervious cover and high-resolution land-cover data from the local jurisdictions to estimate the acres of impervious surfaces per watershed model segment.  For forest and other tree canopy land-uses, the best available data is the University of Maryland's 1-meter resolution statewide tree canopy cover dataset.  Maryland used this dataset to develop estimates for forest, tree canopy over impervious surfaces, tree canopy over turf grass, and tree canopy over open space.  For wetlands, the best available data is the National Wetlands Inventory (NWI) coupled with MD DNR's mapping of wetlands.

The State has identified no spatial datasets for turf grass that conform to the quality standards of this project. This includes even high-resolution land-cover, since most remotely sensed imagery and LiDAR data cannot distinguish between turf grass, hay, pasture, and other low-lying vegetation.  In response, the State has developed interim methods for estimating turf grass areas, and is currently working on methods that utilize a random sampling and statistical modeling approach based on parcel information.  These methods are described in much further detail in the methodology documents available for download below.

These datasets represent the first draft (v1) of the new watershed model land-use, which will be used for the general calibration of the model.  Version 2 of the model land-use will be finalized by September 2016 and the final calibration of the model will begin in October 2016.  Many improvements are planned for the subsequent versions of the land-use.

County Summary Sheets

Allegany Anne Arundel Baltimore County  Baltimore City
Calvert Caroline Carroll Cecil
Charles Dorchester Frederick Garrett*
Harford Howard Kent Montgomery
Prince George's Queen Anne's Somerset St. Mary's
Talbot Washington* Wicomico Worcester

Notes: Three counties did not provide any land-use/land-cover data to the State.  Therefore, to remain consistent in data resolution among various land-use types, CBP methods utilizing regional scale data (i.e., NLCD) are used to develop land-use estimates for these counties.  *Two counties provided data, but did not provide impervious cover data.  Again to remain consistent with the resolution of the data for the other land-use classifications, CBP methods utilizing regional scale data are used to develop land-use estimates for these counties.

Data

The following data files are available for download:

1) The actual Phase 6 land-use dataset that was submitted to CBP by the State of Maryland
    MD Phase 6 Land-Use Data

2) A document containing Maryland's primary QA/QC on the data provided to CBP
    MD Phase 6 Land-Use QA/QC 

3) The P6 watershed model segments
    MD Phase 6 Watershed Model Segments

The following are links to the source datasets used in the development of MD's Phase 6 model land-use:

1) Forest and Tree Canopy (UMD - Leaving MDE website)
    UMD Forest and Tree Canopy Data

2) Impervious Surfaces (Links coming soon)

Methodology Documents

Impervious Surface Methodology Document
Turf Grass Methodology Document
Forest and Tree Canopy Methodology Document
Wetlands Methodology Document

Outreach Materials

April 28, 2015 - Chesapeake Bay Phase 6 Watershed Model Land-Use Development Webinar

MDE and MDP hosted a webinar that discussed the development of the Chesapeake Bay Program's Phase 6 watershed model land-use for Maryland. The Phase 6 modeling tools are being developed to inform the Phase III WIPs. MDE, MDP, and USGS presented on the Land-Use Classifications, Incorporation of Local Jurisdiction Data, and Maryland Specific Methodologies.

Chesapeake Bay Phase 6 Watershed Model Land-Use - MDE/MDP Presentation (PDF)
Using Local Land-Use/Cover Data to Inform the Chesapeake Bay TMDL - CBP Presentation (PDF)
Webinar Audio/Video Recording (leaving MDE website)
Q&A (PDF)

October 26, 2015 - Chesapeake Bay Phase 6 Watershed Model Land-Use Development Webinar #2.

MDE and MDP hosted a second webinar that discussed the Chesapeake Bay Program's Phase 6 watershed model land-use for Maryland.  Specifically, the webinar went over where the data and associated materials can be located on the web for review, the methods that were applied in the development of the dataset, and future improvements to the land-use.

Chesapeake Bay Phase 6 Watershed Model Land-Use - MDE/MDP/Tetra Tech Presentation (PDF)
Phase 6 Land Use Database Versions 1, 2, and 3 - CBP Presentation (PDF)
Webinar Audio/Video Recording (Leaving MDE website)

Local Engagement

More information regarding Chesapeake Bay WIP engagement with MD's local jurisdictions can fe found here. 

Acknowledgements and Questions

The development of this first draft version of the Phase 6 model land-use was a collaboration between MDE, MDP, DNR, and CBP.  For questions, please contact Jeff White with MDE's TMDL Development Program at Jeff.White@Maryland.gov or 410-537-3884, or Stephanie Martins with MDP at stephanie.martins@maryland.gov or 410-767-4559.  October 2015.