Photos of the Long Island Sound

Research & Monitoring

Sea Level Affecting Marshes Model (SLAMM)


  • Click the right arrow to view SLAMM’s sea level rise scenario for Hammonasset Beach State Park (Clinton Harbor) in CT.
  • The model projects regularly-flooded (low) marsh and tidal mudflats displacing irregularly-flooded (high) marsh.
  • Clinton Harbor area marshes in 2010. The different colors depict different land cover types.
  • Clinton Harbor area marshes in 2055. The land cover types are changing.
  • Clinton Harbor area marshes in 2100. The eastern areas of the marsh are drowning, resulting in marshes changing to mudflats.
  • Likelihood of coastal marsh in 2100. SLAMM provides a guide on how likely an area might be a coastal marsh. Darker areas are more likely.
  • Get started on your own research by reading “How Does Slamm Work” manuals (see link below).


click HERE for video to learn what’s on this site

What is SLAMM?

SLAMM (Sea Level Affecting Marshes Model) is a tool that can be used to project how salt marshes may respond to sea level rise.  In essence, SLAMM predicts long term shoreline and habitat class changes as a function of land elevation, tide range, sea level rise, and other environmental factors.

 How Can SLAMM Inform Decision Making?

SLAMM data and maps are one of many resources available to investigate how Long Island Sound’s coastline may respond to sea level rise (SLR). They can show how coastal land cover can change over time under alternative SLR scenarios. These results can help identify adaptation strategies, such as land acquisition, marsh restoration, and infrastructure management.  Click here  to learn more about what SLAMM can do.

Where Can I Find the Long Island Sound SLAMM Results?

LIS SLAMM modeling results are available through three freely accessible web-based map viewers.  Two examine selected results at 2055 and 2100;  the third provides access to all of the results. The buttons below will open the viewers.

We recommend that first-time users should read manuals prepared by the Connecticut Department of Energy and Environmental Protection (CTDEEP) and the Long Island Sound Study  to understand what the viewers are showing and how to use them.  Click here to view the manuals.

We have also put together three tables that show statewide and Soundwide projections. Click here to view the tables. More data reports can be found in the Raw Data section of this site.

Who is Working on the SLAMM Project for Long Island Sound?

SLAMM’s application to Long Island Sound was conducted by Warren Pinnacle Consulting, whose programming and application of the  the model has been used in every US coastal state and national wildlife refuge. The project was commissioned by the federal and state agencies listed below who helped collect and review much of the model’s input data in cooperation with leading academic and other salt marsh ecology experts. The project partners are working with their consultant to improve the data used in SLAMM and are analyzing, and distributing the current LIS SLAMM results for use by all.


Note to Windows 10 users: At this time, Windows 10 users may experience some issues with the SLAMM viewer  in ArcGIS. For example, the search bar tool may not  function in some areas. (You should be able to find locations, however, using the pan and zoom tool.)

Did You Know?


Salt marshes are dynamic ecosystems that provide significant ecological and economic value.  They are also among the most susceptible ecosystems to climate change, especially sea level rise (SLR). See graphic.

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