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Imagine: A hurricane has slammed North Carolina’s coastal communities. There’s water as far as you can see in your Town. How – and where – do you start picking up the pieces left behind by the destruction?
Assessing the damage might seem like the best way to start the process. But places left inaccessible by flooding and damaged roadways may make the assessment intimidating and impractical. Fortunately, remote sensing technologies can solve this problem. WithersRavenel’s Remote Sensing Group Director, Seth Swaim, a licensed drone pilot, a GIS professional, and a professional land surveyor, has firsthand experience documenting the aftermath of storms and hurricanes in North Carolina.
“We have gone out on several different hurricanes to document those types of things – whether it’s a culvert that’s been blown out, washed away, or bridge damage,” he said.
Valuable tool prior to a disaster
Even though drones have proven to be a valuable tool following a natural disaster, their contribution before a weather event can be critical as well. Drones can be an especially valuable tool to build resilience and for climate resiliency planning.
According to Seth, implementation of drones for asset mapping, inventory development, community planning, and emergency management is done on a regular basis. “[Municipalities] can’t repair something after an event if they don’t know where it is in the first place,” he said.
“So, some of the new mapping … technologies that we have are able to help with feature extraction and mapping rather than having to visit every structure,” Seth said.
Compiling drone data during projects
On more and more projects, WithersRavenel’s geomatics team extracts asset features from the data captured by drone flights and from Light Detection and Ranging (LiDAR) datasets, rather than having to send a survey crew or mapping crew to each one of those assets.
“We can pull those locations directly out of our drone data whether we’re doing streetscape projects or downtown master plans or a stormwater project, utilities project, or even a land development project,” Seth said. “We are trying to use that data that we’re collecting for more things.”
Unmanned Aircraft Systems (UAS), or drones, are a vital component of the larger field of remote sensing that also encompasses ground-based and satellite technologies.
WithersRavenel embraced drones as an important feature of its geomatics toolkit early on and has been honing its implementation by keeping up with industry standards and building a growing pilot team.
“We fly more, and we do more remote sensing-type data collection than many others in the industry,” according to Seth.
He believes while drones are widely used by businesses for capturing images and video, his team prioritizes capturing data and extrapolating valuable information for long-term asset management planning and protecting a community’s infrastructure, all of which requires more than just the ability to fly a drone.
For resiliency plans, drone technology provides an opportunity to document and build datasets prior to an event.
“Any shoreline is constantly changing regardless of a hurricane or not, about every day,” Seth said.
Being able to document a shoreline a few days before a hurricane or a natural disaster, or even any other large storm, helps create a baseline to better understand how that shoreline was transformed after a storm, he said.
After disaster strikes
UAS plays an even stronger role in the mitigation process that may be part of a resiliency plan in place for a community affected by a weather event. “A team can get down there and get some pictures in a day and cover a large amount of territory and then have people back in the office to assess all that information,” according to Seth. “That information allows for adding context to what’s happening on the ground.”
The next step following the initial survey of the damage involves getting into the actual mapping or debris volume estimation. Seth explained, “We can use photogrammetry-type of mapping tools to be able to estimate quantities of the debris or floodwaters. So that they understand, ‘OK well, we’re basically going to need X number of dump trucks for X number of days running X hours a day to be able to get all this debris picked up.’”
Challenges after weather event
But operating drones in such a situation is not without challenges, especially when the usual communication networks are down and there’s no power.
“The biggest struggles that we have are communication,” Seth said. “[Everyone] is going through all mobile networks, which overloads that system, which makes it harder for our teams to communicate and connect and get information back to people making decisions.”
Importantly, mobile service providers now set up priority networks, especially for emergency responders. Drones are a handy tool even for the providers in such situations. They now launch “tethered” drones—connected to a generator on the ground—to provide a cellular antenna in disaster zones.
The drone hovers as long as the generator runs and provides a temporary cellular network for the duration, Seth said.
Drones are now more than just a means to shoot pictures from the sky. For WithersRavenel’s geomatics team, they are a critical source of data that can help a vulnerable town or city to weather a natural disaster or bounce back from it. Simply put, drones make a community more resilient.
Contact Seth Swaim at sswaim@withersravenel.com or 919-535-5128 to learn more about how our remote sensing team seamlessly works on WithersRavenel’s multidisciplinary project teams to extract crucial infrastructure data.c
In This Series:
- Prepare, Respond, Recover: WithersRavenel shares how to protect your assets through a natural disaster
- All together now: How asset management, stormwater, and planning can help build community resiliency
- Climate hazard adaptation and mitigation planning: The first steps toward building resiliency for NC communities
- Asset inventory, management can play key role when seeking funding assistance following a disaster
- Stormwater system management and funding are integral to changing weather conditions
- The path forward: How pavement management benefits everyone
- The FEMA BRIC program is a valuable funding source for resiliency projects