Baseline Data Being Compiled To Measure Sea-Level Rise In National Capital Region

Editor's note: Before the government shutdown furloughed most National Park Service staff, research was continuing into climate change across the National Park System. The following article from the agency's Climate Change Response Program News takes a look at monitoring for sea-level change along the National Capital Region of the system.

In order to better track sea-level rise along the East Coast and the related impacts, National Park Service researchers have been building a database of habitat, vegetation, and erosional processes in the agency's National Capital Region.

The research, according to the Park Service's latest Climate Change Response Program News, "focuses primarily on tidal areas of the George Washington Memorial Parkway and National Capital Parks– East to predict changes in biodiversity in these parks resulting from future sea-level rise."

Data is being collected on all lands less than 5 meters in elevation surrounding tidal sections of the Potomac and Anacostia rivers and the Marsh Inundation Model (MAIM), based on the Sea Level Affecting Marshes Model (SLAMM), is used to forecast the impact of a suite of sea-level rise scenarios on marsh and coastal forest habitat area.

Results to Date

Vegetation maps for all of the modeling regions have been completed and validated. Initial model results, incorporating a newly parameterized accretion model, included all final vegetation maps for 2010; summaries by area of all vegetation classes; and models of vegetation change to 2100 for select areas. Model outputs include maps of vegetation classes as well as the amount of conversion from one vegetation class to another.

Work continues on developing an erosion component for MAIM. To date, shorelines were digitized at 3 time steps (1994, 2002, and 2005) for the entire study region and for 2011 at Dyke Marsh from high-resolution aerial photographs. The project team then calculated a historical shoreline erosion rate pre-2005 using linear regression of historical data for each 1-m segment of shoreline.

The model then extrapolates erosion to 2011 (for validation at Dyke Marsh) and into the future using these historical rates.

In addition, the project examines potential changes to marshes from invasive species using invasion vulnerability models for 15 scenarios of future climate (3 for 2030, 3 for 2040, and 9 for 2050) as well as a model for current climate conditions.

The models identify regions of the Earth that could act as potential sources of invasive species to the Potomac and Anacostia rivers study region by quantifying climatic similarity between the study region and all regions of the Earth. The models highlight central Europe as the closest climate match to the study region, with the potential source region increasing in area in the future.

Work will continue in the coming year with the hopes of finalizing output maps for the entire region and completing plant diversity calculations, including predictions of the proportion of species lost due to sea level rise.