Small UAVs for flooding: history, recommendations, missions, and the future

Our thoughts go out to South Carolina and their extreme flooding. We’ve participated in 3 floods, numerous flood exercises, and two summer institutes on flooding.

This blog is divided into 4 sections with some information that we hope may be of use:

  • History of Use of Small UAVs at floods worldwide
  • Recommendations for hobbyists/volunteers who want to fly
  • Missions that have been flown in past floods and the payloads used
  • Other applications of small UAVs

See our previous blogs on small UAVs and flooding (with videos and photos):  general flooding and small UAVs, an update on flooding diasters and the challenges to response ,swift water rescue with UAVs and UMVs, how to fly at floods, data may be the biggest problems at floods, apps for handling data

History of Use of Small UAVs at Floods Worldwide

Small UAVs have been used at least 9 disasters from flooding or had flooding associated with it: Hurricane Katrina 2005* (first reported use of small UAVs), Typhoon Morakot, Taiwan 2009, Thailand Floods 2011, Typhoon Haiyan Philippines 2013, Boulder Colorado floods 2013, Oso Washington Mudslides 2014*, Balkans flooding Serbia 2014, Cyclone Pamela Vanuatu 2014, and the 2015 Texas floods*.  *means that CRASAR participated.

If you are a hobbyist or volunteer and want to fly, some recommendations:

Contact your local fire department and volunteer. Don’t be upset if they decline- it is extremely busy for them and hard to add anything new and relatively unknown to their effort. It is actually illegal to self-deploy UAVs- just like showing up to a police incident with a gun. Even if you have a carry permit, you can’t just show up- you needed to be trained and deputized in advance.

With your local fire department’s permission, contact the local or state air operations. Note that some fire departments or sheriff’s offices may not be aware that during many large scale operations, an agency is responsible for coordinating manned aircraft—especially helicopters working at low altitudes and Civil Air Patrol. Even if you have a 333 exemption, you still need to coordinate with air operations so that you don’t accidently interfere with manned helicopters.

Check to see if the area is under a Temporary Flight Restriction, which is the aerial version of a highway closure.  This is one of those things that you learn about when taking pilot’s licenses and a partial motivation for the FAA’s insistence on at least passing the written private pilot exam.

If you are flying check out the best practices on the home page to see what types of payloads to use for what missions.

Check out the UAViators code of conduct as well for humanitarian use of drones.

Missions Small UAVs have been used for and payloads:

Surveillance/Reconnaissance/Situation awareness for both search and rescue and public works. This is about where’s the flooding? how bad? Are people in distress? What is the state of the transportation infrastructure- roads? Bridges? Typically this is done with video payloads. Rotorcraft offer the advantage of being able to hover and thus give a sense of how fast the water is flowing.

Examination of levees for signs of overflow over the top or for seepage indicating incipient collapse. This can be done with visual inspection using video payloads or with a camera payload for photogrammetrics. If you are going to try to create a 2D or 3D photogrammetric reconstruction, you will want GPS stamped high resolution imagery.

Missing persons, both living and presumed drowned and tangled in debris. This is done with high resolution still imagery that geotagged (if you don’t the have the GPS stamp, then it’s hard to direct a team to the right spot). Note CRASAR has software developed by the NSF REU Computing for Disasters program that uses computer vision to help identify victims in flood debris. It’s yet not released for general use but we can run it internally.

Delivery to trapped people. Keep in mind three concerns with the use of small rotorcraft and we recommend extreme care when flying near people. The first concern is that hanging things off of a small UAV changes the dynamics of the vehicle and how well it can be controlled, so it may behave and move unpredictably. Hoisting a fishing line tied to a heavier line tied to the object may be a good way to go. The second is that operators tend to lose depth perception and may get far too close to objects and people. The third is that work by Dr. Brittany Duncan shows that people aren’t naturally afraid of rotorcraft and will let them get dangerously close, so a person may be likely to be injured by a sudden move of a too-close UAV.

Other applications that have been discussed but not reported at an actual disaster:

Swift water rescue: UAVs providing oversight on floating debris that might jeopardize crews in boats working to rescue trapped people

Restoration and recovery assessment: such as identifying easement and standing water conditions that prevent power utility crews from restoring electricity

Carrying wireless repeater nodes: this has been done by Civil Air Patrol manned aircraft, so the advantage of small UAVs is unclear

Debris estimation: both the debris directly from the flood and the indirect debris a few days or weeks later from people having to rip out sheet rock and carpets. The advances in photogrammetrics make it possible to estimate the volume of debris— if you have the “before” survey of the area; we flew with PrecisionHawk at the Bennett Landfill superfund site in February in order to estimate the volume of toxic trash (which was on fire) that needed to be safely removed. The next step is to estimate the content, because vegetation and construction materials have to get handled and processed differently.



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