Stormtide study will map Island inundation pathways

Center for Coastal Studies works with MVC and Oak Bluffs to better understand Vineyard flood routes.

The Center for Coastal Studies is working with the MVC and the town of Oak Bluffs to map stormtide pathways in preparation for storms and sea level rise.

The Center for Coastal Studies (CCS) is working with the Martha’s Vineyard Commission (MVC) and the town of Oak Bluffs to identify stormtide pathways on-Island caused by sea level rise and storm surge.

The project is Islandwide, but as a leader in coastal management and climate change planning, Oak Bluffs has been awarded a $300,000 grant through the Coastal Zone Management resiliency program.

The project seeks to provide critical data for emergency response and preparedness, and offer a vital climate adaptation planning tool that can be easily accessed and used by both local officials and members of the public. 

Liz Durkee, climate change coordinator for the MVC, and Climate Resilience Committee chair, said during a public Zoom meeting Monday that the stormtide pathways program will be a major help in putting together a Vineyard plan to deal with climate change.

She added that the local match for the grant is 25 percent, and said that with government budgets being so tight due to the pandemic, any contributions toward the match are welcomed. 

The CCS is a nonprofit organization based in Provincetown that uses applied research, education, and public policy initiatives to preserve coastal ecosystems.

According to Durkee, CCS has conducted over a dozen stormtide programs along Cape Cod and other coastal areas of Massachusetts.

Dr. Mark Borrelli, chair of the marine geology department at CCS, said the first year of the two-year program will consist of data collection and analysis.

After mapping all stormtide pathways on-Island, the second year of the project will consist of taking inventory of low-lying roads and related infrastructure that would be affected by inundation.

That mapping data will then be sent to the National Weather Service, where it will use its advanced modeling software to create digital models that can be used by emergency responders and planners. “We are partnering with [the NWS] to put this data onto their realtime coastal flood and inundation mapping website,” Borrelli said. 

But even more exciting, Borrelli said, is the development of a standalone application that will be available on a CCS-hosted web platform. “It’s similar to the NWS website, but different in that the center is hosting the page, so we can change it and add new data and features,” Borrelli said.

According to Borrelli, there are a number of websites that show the extent of flooding in particular areas, but he said the CCS stormtide mapping will show what route the water is taking to get there.

“We don’t do modeling, we do actual mapping, getting on the ground on the Island,” Borrelli said, and noted that both methods of illustrating data are useful in their own way: “We don’t see one versus the other — modeling has its advantages, just like mapping does.”

Borrelli said Provincetown has used this type of information in the past to prepare for oncoming storms. But the data isn’t just valuable for emergency response officials. Borrelli said everyone will have access to the standalone web app, which will increase not only resiliency, but autonomy for Islanders. “People should be able to access this information and prepare. This is for first responders and planners, but it’s also for everyone,” Borrelli said.

The CCS uses data sets provided by the National Oceanic and Atmospheric Administration (NOAA) that it gathers using light detection and ranging (lidar) technology.

Lidar is like radar or sonar, but instead of using radio waves or sound waves, Borrelli said, it bounces light off the surface of the Earth to create a detailed topographic map.

Using mapping software, folks at CCS can overlay an image of the surface (provided by NOAA lidar) with flood data collected through on-the-ground mapping.

In order to attain the level of detail needed to map stormtide pathways, Borrelli said, researchers at CCS will go to certain flood areas indicated by the NOAA lidar, and check them manually using real-time kinematic GPS, which is highly accurate.

For Borrelli, the project isn’t just about planning for weather events using existing information, but making sure any unprecedented storms can be managed using stormtide mapping. “Every first responder, every police officer, every emergency department person — they know where the water goes during the big storms,” Borrelli said. “What they don’t know, what nobody knows, is where the water is going to go when it’s six inches higher than it’s ever been.”