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COAST - Built on the Global Mapper SDK

Coastal Adaptation to Sea Level Rise Tool (COAST)

Blue Marble Geographics has partnered with the New England Environmental Finance Center (NEEFC) from the Edmund Muskie School of Policy Research at the University of Southern Maine to develop the software interface for COAST. The COAST software tool, a free download, is built on the Global Mapper software developer toolkit and promoted in partnership with Catalysis Adaptation Partners.

COAST (COastal Adaptation to Sea level rise Tool) is a process that helps users answer questions in regards to the costs and benefits of actions and strategies to avoid damages to assets from sea level rise and/or coastal flooding.

  • Should we build a sea wall?
  • Should we develop a proactive building ordinance?
  • Should we build a levee?
  • Should we change our zoning?
  • Should we relocate?

COAST is a technical tool, but its primary added value is in how it is used. In the COAST approach, our associates at CAP help your organization or community connect technical results with the social, political, and economic realities of local adaptation, in a way that empowers stakeholders to actively engage in discussions about their future. Being entirely stakeholder driven, and using locally derived data on vulnerable assets and candidate adaptation actions wherever possible, COAST results generate enthusiasm and buy-in not available through most approaches.

What to do about:
Photo of a wave spilling over onto a coastal roadway

Should you?
Photo of an engineer walking on a sea wall

Use COAST to find out:
Screen capture of COAST software displaying 3D data of projected sea level rise along a coastline

The above output shows the results from a COAST analysis as displayed in Google Earth. COAST outputs 3D spatial data representing damage from Sea Level Rise (in red) and Storm Surge (in blue) as KML or KMZ files that can easily be loaded and viewed in Google Earth. This is a great way for organizations participating in a COAST analysis project to share the results of their flood study with the greater community.

Another example of COAST graphic output is below, showing a no-adaptation-action scenario for 1 meter of sea level rise and a 10-year flood event in the year 2070, for a portion of downtown Mystic Seaport in Groton, Connecticut. The z-axis polygons represent cumulative expected lost real estate and building contents value of over $8.7 million (maximum loss per parcel is over $800,000). Adaptation actions subsequently modeled in this location included installing a hurricane barrier, elevating a road, and building dikes, each of which could provide some protection to the vulnerable areas.

Visually, each adaptation action was then represented in maps showing reduced or eliminated polygons extruding out of the landscape. Numerically, this is an effective way of showing up front and maintenance costs of hard-structure approaches versus expected damages from particular inundation events. Soft-structure approaches may also be modeled, such as flood-proofing, rezoning over time, and others. Importantly, the approach allows modeling of ranges, sea level rise, storm surge frequency and intensity. Combining multiple future scenarios provides stakeholders an opportunity to select their expectation of future conditions and then visualize damages under action versus no-action scenarios.

The approach also encompass more than just single-event modeling. For multi-decade periods, it produces cumulative expected damage tallies in tabular form for a given set of conditions and adaptation actions. This allows numeric understanding of expected damages from increased flood frequency over time, as well as identification of robust adaptation strategies that may function acceptably and save money under any climate scenario.

COAST output is in the form of 1) files compatible with Google Earth and 2) tables showing cumulative expected damages for the selected vulnerable asset under the adaptation scenarios stakeholders have developed, that allow cost-benefit analysis of candidate adaptation actions.

Screen capture of COAST software displaying 3D data of projected monetary flood damage along a coastline

The COAST software was developed at the University of Southern Maine with funds from the US EPA, and in collaboration with partners at Battelle, the Maine Geologic Survey, the University of New Hampshire, and Blue Marble Geographics. With this software, users will be able to conduct basic cost-benefit analyses themselves. Depending on user skill sets and the nature of assets and adaptation actions being modeled, consulting assistance may be required and is available through CAP.