Maryland Analyzes Coastal Wetlands Susceptibility to Climate Change

Oepa.gov/arc-x/maryland-analyzes-coastal-wetlands-susceptibility-climate-change

Maryland, a state many consider synonymous with
coastal life and livelihoods, has already experienced
the loss of several islands and vast acreage of
shoreline due to erosion and sea level rise. Maryland's
coastal wetlands are particularly vulnerable to projected
climate changes and are already experiencing threats
from storms, inundation, and sea level rise -which is
occurring at nearly twice the global average-.

Accordingly, Maryland's Department of Natural
Resources (MDNR), in partnership with the Maryland
Department of the Environment (MDE), has sought to
implement wetland restoration and conservation
programs to protect the state's remaining coastal
wetlands from climate change.

Maryland used the Sea Level Affecting Marshes Model
(SLAMM) to factor in sea level rise projections and gain
a comprehensive look at coastal wetland areas
throughout the state. This analysis is allowing the state
to better identify the wetland migration areas under
future sea level rise conditions and identify high priority
wetland areas for protection. Data on wetland characteristics including size, species composition, and ecosystem connectivity
has helped inform adaptation options by helping identify and prioritize land necessary for preserving current and future
ecosystem diversity and functionality. The analysis enabled MDNR officials to provide information on high priority and
vulnerable areas for conservation purposes to land managers, conservation planners, and the public. Consequently, this
analysis provides land use planners and conservation organizations valuable information to help preserve areas for wetland
migration and adapt to higher sea-levels.

How Did They Do It?	Applicable EPA Tools

Acknowledged the threat and devised a strategy to analyze vulnerability

•	Maryland's Climate Action Plan, the first component of a two phased strategy for
adapting to sea level rise and coastal storms, specifies the extreme vulnerability of
coastal wetlands and identifies the need to adapt to future conditions and "direct
existing land conservation programs... to consider the use of conservation
easements and other land conservation initiatives as a means to protect key coastal
areas vulnerable to sea-level rise and to provide sufficient lands for wetland
migration."

•	The 2011 Maryland Commission on Climate Change "Building Societal, Economic
and Ecological Resilience" report served as the second phase of this strategy by
providing a suite of actions to address climate change. Among the actions
recommended were to use downscaled projections of climate conditions as well as
potential "at-risk" species and habitats to better inform land management and
protection goals for critical areas including "saltwater marshes in danger from
erosion", and "tracts of upland habitat where wetlands migration is likely to occur as
sea level rises."

Figure 1, These maps are outputs of SLAMM that display high priority nearshore
wetland* coincident with the green infrastructure network and high-priority water-
sheds identified in the blue infrastructure analysis, given sea level rise projected for
2100 in the Chesapeake Bay and a portion of Maryland's Eastern Shore.

High Priority Conservation Areas Identified from the SLAMM Analysis.

The Scenario Based
Projected Changes Map can
illustrate scenarios of
projected changes in annual
precipitation, 100-year storm
events, and sea-level rise to
identify climate threats to the
coast.

Scenario Based Projected
Changes Map

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How Did They Do It?

Applicable EPA Tools

Maryland developed an analysis to identify areas for current and future acquisition to
spur climate adaptation of coastal wetlands

• Maryland used the Sea Level Affecting Marsh Model (SLAMM) to assess wetland
migration and distribution under the projected sea level for the year 2050 and 2100.
The analysis used a projection of 1.04 meters of sea level rise by 2100 that was
between the range of 2.7 ft and 3.4 ft of sea-level rise that The State's Climate Action
Plan projected based on two different emissions scenarios.

° Sea Level Affecting Marsh Model (SLAMM)

Download the Sea Level
Affecting Marsh Model
(SLAMM Tool) from the U.S.
Climate Resiliency Toolkit to
help analyze wetland
migration under projected
sea level rise.

U.S. Climate Resiliency
Toolkit

Identified "Targeted Ecological Areas" that would provide potential migration zones
and integrated adaptation criteria into existing programs

•	Maryland published the SLAMM analysis on a public coastal GIS dashboard, The
Maryland Coastal Atlas, under the title "The Estuaries Wetland Change Tool" in order
to help encourage integration of the analysis into public and private coastal
conservation efforts.

•	Maryland used this analysis to update a GIS Mapping System "GreenPrint" that
models state designated "Targeted Ecological Areas," which are lands and
watersheds of high ecological value that have been identified as targeted
conservation priorities by the Maryland Department of Natural Resources (DNR).

Synthesis of Adaptation
Options for Coastal Areas
Guidebook helps identify
climate risks to coastal
ecosystems and review
adaptation options available
to coastal managers.

Synthesis of Adaptation
Options for Coastal Areas
Guidebook

The Rolling Easements
Primer can help identify
more than a dozen land use
and legal tools for ensuring
that intertidal habitats can
persist even as sea level
rises.

Rolling Easements Primer

Similar Cases and More Information

For more information view the EPA's 2015 State Water Agency Practices for Climate Adaptation - Maryland Document or view
the U.S. Climate Resiliency Toolkit Case Study. To see another example of how a coastal community assessed their
vulnerability view the Southwest Florida Salt Marsh Vulnerability and Adaptation Plan, or the San Juan Estuary Vulnerability
Assessment. To learn more about how climate changes can affect natural resources and threaten drinking water availability
through saltwater intrusion, see how Tampa Bay Water diversified their source water to promote resiliency to current and
future conditions.

•	2015 State Water Agency Practices for Climate Adaptation - Maryland Document

•	U.S. Climate Resiliency Toolkit Case Study

•	Southwest Florida Salt Marsh Vulnerability and Adaptation Plan

•	San Juan Estuary Vulnerability Assessment

•	Tampa Bay Diversifies Water Sources to Reduce Climate Risk

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