This mathematical model uses digital elevation data and other information to simulate potential impacts of long-term sea level rise on wetlands and shorelines. SLAMM has been used in several geographies and applications across the nation since its development in the mid-1980s.

Features
- Addresses various wetland scenarios, including inundation, erosion, overwash, saturation, and salinity
- Computes relative sea level change for time sequences of 5 to 25 years
- Incorporates areas protected by dikes and other hard structures if needed
- Incorporates sedimentation and accretion rates and provides options for computing erosion
- Incorporates standard coastal wetland classes
- Provides outputs that can be viewed in a geographic information system (GIS) or other software for additional analysis
Technical Specifications
- Microsoft Excel (for viewing output tables)
- Microsoft Word (for viewing outputs)
- ArcGIS (for viewing outputs in a mapping environment)
Data Requirements
- National Wetlands Inventory data
- Digital elevation data
- Optional data sets (see the technical documentation for more information):
- Protected area data or dike data
- Site parameters to change water depth, accretion rates, erosion rates, and many more
Note: All analysis data must be in raster formats, clipped to the same study area, and named in a similar format. See technical documentation for more information.
Stories From the Field
Identifying Conservation Priorities for Sea Level Rise Adaptation in Coastal Maryland
Maryland used the Sea Level Affecting Marshes Model (SLAMM) to identify high-priority conservation areas that allow for wetland migration and future wildlife habitat.
Using Geospatial Techniques to Plan for Climate Change Impacts on Coastal Habitats in South Carolina
Partners used the Sea Level Affecting Marshes Model and Habitat Priority Planner to identify priority lands to conserve as sea level rises.
Visualizing the Impacts of Sea Level Rise in Delaware
Lidar data were used to generate maps showing the possible impacts of inundation using three different sea level rise scenarios.
Other SLAMM Projects
The Warren Pinnacle Consulting website lists several current and recent projects utilizing SLAMM.
Support
Warren Pinnacle Consulting provides several resources for more in-depth information on the Sea Level Affecting Marshes Model (SLAMM).
SLAMM-View (developed by Image Matters and U.S. Fish and Wildlife Service)
Displays SLAMM simulations under three sea level rise scenarios over 25-year increments
Get It Now
- Significant improvements to the model include
- Accretion Feedback Component: Feedbacks to vertical accretion of wetlands based on elevation, distance to channel, and salinity may be specified.
- Salinity Model: Multiple time-variable freshwater flows may be specified. Salinity is estimated and mapped at mean lower low water, mean higher high water, and mean tide level. Habitat switching may be specified as a function of salinity.
- Integrated Elevation Analysis: SLAMM will summarize site-specific elevation ranges for wetlands as derived from lidar data or other high-resolution data sets.
- Flexible Elevation Ranges for Land Categories: If site-specific data indicate that wetlands range beyond the SLAMM defaults, a different range may be specified within the interface.
- Improved Memory Management: SLAMM no longer requires contiguous memory, which improves memory management considerably.
- SLAMM 6 allows a user to import a spatial map of uplift and subsidence.
- Additional and significant graphical user interface upgrades were completed.
- Please refer to the technical documentation for more information on the changes from SLAMM version 5.0 to 6.0.
All model results are subject to uncertainty because of limitations in input data, incomplete knowledge about factors that control the behavior of the system being modeled, and simplifications of the system.