Feature Stories

Mapping the king tide flood

By Christopher James, Office of Public Service and Outreach

Tybee Island - It was exactly the kind of event the Sea Level Rise app was built for and the University of Georgia was on site to take advantage of the new technology.

When the king tide struck Tybee Island on the morning of Oct. 28, some of the most dramatic scenes weren't on the well-known beach outside Savannah but inland, in neighborhoods a few blocks away.

"We saw today where the stormwater infrastructure is and what a key role that plays in these events," said Mark Risse, director of Marine Extension/Georgia Sea Grant, a unit of the UGA Office of Public Service and Outreach.

"Some of the areas more inland might be where we see worse flooding and that goes against intuition that says it's going to happen right on the edge where the ocean is meeting the land. It's not common sense predicting where these things can happen all the time. If we can document these things, maybe we can go back and correct them."

The app records where and when flooding is happening via GPS coordinates and pinpoints trouble spots. (Photos by Shannah Cahoe Montgomery)The app records where and when flooding is happening via GPS coordinates and pinpoints trouble spots. (Photos by Shannah Cahoe Montgomery)

Risse led a group of Marine Extension and Georgia Sea Grant  staff members on Tybee who were using the smartphone app to document nuisance flooding related to unusually high tides brought on by the alignment of the moon, sun and Earth.

Over time, "citizen scientists" could be trained to use the app to record where and when flooding is happening via GPS coordinates and pinpoint trouble spots, Risse said. The concept is similar to traffic apps like Waze that show accidents and congestion in real time.

Not much data has been collected on these localized floods, which is where the app could fill a significant gap.

"That kind of information hasn't been collected by scientists," said Shana Jones, planning and environmental services manager at the Carl Vinson Institute of Government. "The modeling scientists do related to flooding is much more 100-year floods — the big floods."

Scientists have only recently begun modeling the smaller floods, which can have a big impact on local communities.

Building up a database over time could reap big benefits. Being able to analyze this kind of flooding at a granular level will allow planners to assess how effective storm drain modifications or other improvements are. It also allows cities to prioritize areas where repeated flooding occurs.

Historically, Marine Extension and Georgia Sea Grant have engaged volunteers to collect data on a number of projects, including water-quality testing.

The Sea Level Rise app, created by Norfolk, Virginia-based Wetlands Watch and developer Concursive, is being pilot tested up and down the East Coast, including by UGA Marine Extension and Georgia Sea Grant.

 

 

 

Published Tuesday,