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About the Delaware Bay Wetland Projections

On this page:
  • About the DB Wetland Project
  • History
  • Datasets
  • Publications

About the Delaware Bay Wetland Projections

Get the Report
Cover of the final Sea-Level Affecting Marshes Model Report (2019)
(Main Report,74 pp, 5 MB, About PDF)

Coastal salt marshes - which provide valued ecosystem services such as flood control, water purification and critical habitat - are vulnerable to ongoing sea level rise, which is interacting with physical and biological attributes of the system to induce complex changes in salt marsh habitats.

For salt marshes such as those in the Delaware Bay, management techniques need to be adapted to account for these effects when carrying out activities to preserve valued salt marsh areas.

To explore the dominant processes involved in determining distributions of wetlands across space and time under conditions of accelerated sea level rise (SLR) in the Lower Delaware Bay, we used SLAMM (version 6.7) to generate spatially-explicit projections of SLR-induced changes in acreage for seven salt marshes. Four of the marshes are located in New Jersey (Dividing, Lower Maurice, Dennis, Reeds Beach) and three are located in Delaware (Broadkill, Mispillion, Lower St. Jones).

The EPA report presenting the results is divided into three sections:

  1. projected changes in all SLAMM land cover categories,
  2. projected changes in high, low and total salt marsh acreage, and
  3. sensitivity analyses to assess the relative effect on model outputs of key input variables (Great Diurnal Tide Range (GT), salt elevation, marsh erosion, and accretion rates).

SLAMM is widely recognized as an effective model to study and predict wetland responses to long-term SLR and has been applied in every coastal U.S. state.

SLAMM is widely recognized as an effective model to study and predict wetland responses to long-term SLR and has been applied in every coastal U.S. state. Our methods differ from prior SLAMM work performed in the Delaware Bay, in that we derived results for specific marsh areas (habitat types) and utilized more recent, higher resolution elevation data, the most recent SLR projections, and site-specific accretion data. These SLAMM simulations support a larger project by the EPA on frameworks and methods for characterizing relative wetland vulnerabilities and applying the results to support adaptation for more effective management strategies.


History of the Delaware Bay Wetland Project

Below is a list of important milestones.

Date Milestone
May 2020 The Delaware Bay Wetland Projections were incorporated into the Global Climate Explorer (GCX) set of tools and website.
Apr 2019

EPA released the report, Application of the Sea-Level Affecting Marshes Model (SLAMM) to the Lower Delaware Bay, with a Focus on Salt Marsh Habitat.


Datasets

ESRI raster files of projections for Delaware Bay Wetlands

Dataset Description Datasets Metadata
Saltmarsh Gain/Loss Projections at Broadkill, DE
Format: ESRI Raster
BDK_HM.zip
BDK_LM.zip
BDK_TM.zip
High Marsh Projections at Broadkill
Low Marsh Projections at Broadkill
Total Marsh Projections at Broadkill
Saltmarsh Gain/Loss Projections at Mispillion, DE
Format: ESRI Raster
Misp_HM.zip
Misp_LM.zip
Misp_TM.zip
 High Marsh Projections at Mispillion
 Low Marsh Projections at Mispillion
Total Marsh Projections at Mispillion
Saltmarsh Gain/Loss Projections at St. Jones, DE
Format: ESRI Raster
StJLow_HM.zip
StJLow_LM.zip
StJLow_TM.zip
High Marsh Projections at St. Jones
Low Marsh Projections at St. Jones
Total Marsh Projections at St. Jones
Saltmarsh Gain/Loss Projections at Dennis, NJ
Format: ESRI Raster
Dennis_HM.zip
Dennis_LM.zip
Dennis_TM.zip
High Marsh Projections at Dennis
Low Marsh Projections at Dennis
Total Marsh Projections at Dennis
Saltmarsh Gain/Loss Projections at Dividing, NJ
Format: ESRI Raster
Dividing_HM.zip
Dividing_LM.zip
Dividing_TM.zip
High Marsh Projections at  Dividing
Low Marsh Projections at  Dividing
Total Marsh Projections at  Dividing
Saltmarsh Gain/Loss Projections at Lower Maurice, NJ
Format: ESRI Raster
MaurLow_HM.zip
MaurLow_LM.zip
MaurLow_TM.zip
High Marsh Projections at  Lower Maurice
Low Marsh Projections at  Lower Maurice
Total Marsh Projections at  Lower Maurice
Saltmarsh Gain/Loss Projections at Reeds, NJ
Format: ESRI Raster
Reeds_HM.zip
Reeds_LM.zip
Reeds_TM.zip
High Marsh Projections at  Reeds
Low Marsh Projections at  Reeds
Total Marsh Projections at  Reeds
SLAMM Output Raster Symbology
Format: ESRI Shapefile
Symbology.Zip SLAMM Output Raster Symbology

Publications

EPA Reports

  • U.S. EPA. Application of the Sea-Level Affecting Marshes Model (SLAMM) to the Lower Delaware Bay, with a Focus on Salt Marsh Habitat. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-18/385, 2019.

Global Change Explorer (GCX)

  • Critical Loads
  • Ecosystem Management
    • Adaptation Design for Coral Reef Restoration
    • Adaptation Design Tool
    • Delaware Bay Wetland Projections
  • Integrated Land Use
    • 4th National Climate Assessments
    • ICLUS Downloads
  • Location Scenarios
  • Resilience
  • Watersheds
Contact Us about GCX
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on January 31, 2025
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