Visualizing coastal flooding helps public support change

June 28, 2013

People who live in coastal areas most vulnerable to flooding are already more aware than others of the risks of increasing storm surges and sea level rise, but tools that aid the public in visualizing future damages help bring people on board for change.

“Climate change visualization tools are a necessity because narrative is not enough to convey the depth of the problem,” said Lisa C. Dickson, Vice President for Sustainability at the consulting firm Kleinfelder.

Her firm has been working with the Massachusetts towns of Scituate, Duxbury and Marshfield since last year under a $30,000 New England Municipal Coastal Resilience Initiative Grant from the Gulf of Maine Council on the Marine Environment.

On May 16, 160 people from the region attended a public meeting in the Scituate Harbor Community Building to see the maps Kleinfelder prepared.

“It was well-received. We were happy to see it,” said Dickson. “Some people even said they thought our estimates were ‘under’ for some areas. And they probably were, because we had no wave dynamic included.”

The firm used the SLOSH (Sea, Lake and Overland Surges from Hurricanes) computer model devised by the National Hurricane Center to estimate storm surge heights and winds resulting from hurricanes. The model allows them to look at all kinds of events, then go on to create a storm with all the appropriate characteristics.

“This is the first step in people understanding the issue. The next time, the wave dynamic will be added to the SLOSH inundation model,” said Dickson.

The firm and the towns had to agree on the information to include before collecting the data, distilling it and creating the maps. The options include how far in the future to project scenarios, whether to use the highest projections or lower ones, whether to include sea level rise or storm surge information or both, and a host of other variables.

“There are political ramifications for which scenario you use,” explained Dickson. The three towns in the South Shore project chose to use the highest projections, which aligned with most other projects being done by Kleinfelder for several other Boston-area sites.

“A big deliverable for the South Shore project is graphics. We show inundation for sea level rise and storm surges, both coupled and uncoupled, (as separate events, or together) and we show them 25, 50, and 75 years out.”

Laura Harbottle, town planner for Scituate, said certain areas of the town “face the Atlantic at the right angle to get hammered by Nor’easters. There’s nothing to break the wind and water, so those areas already have the worst flood losses.”

Photo: Kleinfelder

“People are getting a sense of how serious the issue is and how they need to get involved with building their houses up,” said Harbottle. “Often they can’t move their houses back because of space constraints, so elevating the house is the only way to go.”

Harbottle said the timing of the South Shore project works well with a Federal Emergency Management Agency (FEMA) grants program for elevations the town has been participating in for 15 years or so.

“We are already engaged in trying to educate people of the importance of preparing for climate change,” said Harbottle. “This is dovetailing with efforts the town is already making, so people will get involved earlier with getting their homes elevated.”

She said up to 55 homes have already been elevated under the FEMA grant program, but “a fair amount still haven’t done it.”

Although several types of storms could hit the South Shore, the budget constraints limited researchers to one, so the towns also chose to use the Nor’easter as the most likely event to affect their area, even though the NOAA-based SLOSH model doesn’t offer Nor’easter as an option.

“It’s based primarily on hurricane data, which is a bit different, but a Level 1 hurricane is a pretty good replacement for a Nor’easter,” said Dickson. The model uses new LIDAR (Laser Imaging Detection and Ranging) high-definition aerial photography with elevational data.

“It gives us a horizontal revolution of one foot, so we should know where all the sea walls are, so we understand horizontally and vertically what everything looks like,” Dickson explained. The inundation model shows flooding levels. Kleinfelder created a series of maps across the three municipalities.

For the public meeting, they agreed to show only the 25- and 75-year projections, including sea level rise (SLR) with storm surges in the same place—four depictions for each area. The SLR curve is based on 2012 global data from the federal draft Third National Climate Assessment.

Kleinfelder has 60 offices all over the country, as well as in Australia and Canada, employing 2,000 people working in engineering, science and architecture.

“We focus on all kinds of infrastructure problems,” Dickson said. For something such as the South Shore project, the firm collects the necessary data, figures out the targets at risk – particularly municipally-owned infrastructure such as sewage treatment plants and dike structures, then recommends a “laundry list” of strategies that could be adopted. Then the list is honed by doing a cost-benefit analysis of the options, and discounting less important things such as bike paths.

Dickson sees minds changing in a big way around planning for climate change adaptation techniques. One good example is Boston’s Logan Airport, an urban airport located in the city and on the harbor. Some runways are built out into the harbor.

After Hurricane Sandy devastated New York and New Jersey’s coastlines, the leadership at Logan, once positive that no planning needed to be done in the foreseeable future to adapt to sea level rise or storm surges, suddenly appropriated $500,000 for a feasibility study. Sandy hit Logan with less force and at low tide, so failed to do the kind of flood damage the New York-New Jersey region incurred. But the wind damage that occurred in Boston was enough to prompt the study.

“There are enough extra events now that the old-school public works people are finally realizing they don’t have enough capital budgets to keep fixing things,” said Dickson. “People are looking at the economics of doing nothing.”

Canada has the Regional Adaptation Collaborative (RAC). In New Brunswick, Dr. David Lieske, assistant professor at Mount Allison University in Sackville, also knows the value of visualization tools. As part of anRAC-funded project, last March 1, Lieske and consultant Lori Ann Roness gave a public presentation on “Talking About Climate Change, Cultivating Social Change” at the University of New Brunswick’s Wu Conference Centre in Fredricton.
Lieske created visualizations, worked with focus groups, talked to people from all walks of life, then followed up with questionnaires.

“It didn’t matter what kind of visualization we showed them, almost everyone came out with an increased sense of risk and an elevated sense of the urgency of the problem,” said Lieske. In his area, sea level rise and storm surges will impact the dykes that protect not only the agricultural fields for which they were designed, but to a lesser degree the entire transportation system—roads and railroads.

“A one in 10-year flood of 8.9 meters, a modest flood, could overtop 90 percent of the dykes,” said Lieske. Although all the visualizations his team employed increased knowledge in the people who saw them, Lieske said animations worked best.

“They were more emotionally provocative than a regional map,” he said. “I definitely think there was an emotional change in seeing an animation. We are flooded rarely, so we get complacent and don’t think about it.”

He adds that the public finds a lot of information “hard to digest” and visualization technology can help with that—both web maps and interactive web tools.

The next steps for the South Shore project include finalizing the maps, creating a few 3-D visualizations and analyzing the economic impacts of future flooding.

“We will do 3-D visualizations on a few buildings – five structures with a 3-D pedestrian view, Dickson said. “At a high tide, they will show where the high water mark would be.”

“The thing I like about working on climate change is incorporating the built and the natural worlds,” said Dickson. “Climate change is driving what the landscape will look like and how we will approach what is built.”


Scituate home page with link to slide show shown at 3-town public meeting:

“Talking About Climate Change, Cultivating Social Change”,%20Cultivating%20Social%20Change.pdf

Massachusetts Homeowner’s Handbook to Prepare for Coastal Hazards

Local Mitigation Planning Handbook

Local Mitigation Plan Review Guide

Eastern Region Quarterly Climate Impacts and Outlook

Adaptation to Climate Change Report

Coastal Flood Risks: Achieving Resilience Together



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