Mapping Hurricane Sandy’s Aftermath in Haiti

Insect-like Drones from SenseFly Provide Data Quickly for ArcGIS Technicians at IOM

A 2.888Mb PDF of this article as it appeared in the magazine complete with images is available by clicking HERE

After Hurricane Sandy hit Haiti in August, 2010 the International Organization for Migration (IOM), a leading intergovernmental organization in the field of migration, joined the international community in helping the Haitian people pick up the pieces. IOM uses Esri ArcGIS software to map out, assess, and respond to community needs all over the world.

Since the landscape of Haiti had changed significantly, due to flooding and storm surge, the agency discovered that map data needed to be updated. To meet the challenge, IMO turned to a unique, almost futuristic solution–insect-like drones–that could remotely capture this data quickly and safely. IMO GIS technicians could then supply aid officials what they needed: a clear, accurate, real-time understanding of conditions on the ground.

Years of disasters
Haiti sits in a hurricane corridor in the Atlantic Ocean, and as a result, tropical storms regularly wreak havoc on the Caribbean country. In recent years, Haiti has been inundated with natural disasters. A magnitude 7.0 earthquake shook the nation in January 2010. Two years later, Tropical Storm Isaac hit in August 2012, and a few months later, Hurricane Sandy snapped its tail at the country in October.

Each of these disasters had a devastating impact on the country and its inhabitants. Even though most of Hurricane Sandy was concentrated offshore, more than 20 inches of rain fell on the south and southwest coats of Haiti in just four days.

The hurricane left as many as 200,000 people with damage to their homes. Add this to the 390,000 people still without homes after the January 2010 earthquake and now, according to the United Nation’s Office for the Coordination of Humanitarian Affairs, 3.5 percent of people living in the capital city of Port-au-Prince live in tents.

Many people have been killed by the events themselves or the health crises that resulted. For example, a terrible cholera outbreak occurred after the 2010 earthquake due to lack of clean water. Almost 6 percent of the population has been affected, and the disease has taken the lives of 7,500 people.

Hunger is another constant threat. Floods from Sandy washed away many crops, including plantain, maize and sugarcane. Hurricane Sandy was, as Prime Minister Laurent Lamothe described, a disaster of major proportions.

These humanitarian emergencies are difficult to treat when the landscape keeps changing. Buildings crumble and roads disappear during such devastating events. Sandy turned dirt roads and paths into torrential flows of water. Refugees set up shelters and, in many cases, entire new cities in short time. Mapping this changing landscape takes on an urgency that might not exist in more stable countries.

Do Like the Bees Do
That was the thought when the IOM got to work in Haiti after Hurricane Sandy. IOM works to help migrants in need, including assisting the Haitian government’s civil protection agency (DPC) and the Haitian Red Cross. IOM has been assisting in Haiti for many years and has made some great strides in helping the country prepare to mitigate such devastating events.

For this particular event, IOM provided the logistics for Drone Adventures, a nonprofit organization based in Lausanne, Switzerland, to fly a mission using drones to collect imagery for up-to-date maps. OpenStreetMap France, a collaborative community of people and organizations who provide mapped information for anyone to use, requested the mission. And the imagery is freely available for anyone to use.

Autonomous ultralight flying vehicles (UAVs) created by SenseFly, a small company also based in Switzerland, were used to capture data in support of this mission. SenseFly is unique in that the founders of the company, a team of robotics researchers at the Laboratory of Intelligence Systems–also from Switzerland–first studied the behavior of flying insects, such as bees and houseflies, to understand how best to control and navigate the drones.

Why insects? SenseFly researchers have found that by creating a highly integrated autopilot for the drone, it flies in a manner similar to how a fly or bee zooms about, making the drone more efficient, elegant, lightweight and smarter.

Drones, Not Digitizing
Drones in general are being looked at more and more for acquiring map data that is needed quickly and have the advantage for collecting that data from areas that might be considered unsafe due to damage from natural disasters, much like Haiti.

The artificial intelligence found on board the SenseFly drones allows them to fly autonomously and make decisions in flight, such as returning to base because of a low battery. They are also equipped with sensors that monitor the flight in real time. These sensors include GPS, altimeter, and wind-speed sensors so the resultant imagery collected from the installed camera is highly accurate.

Sensefly’s eBee drone comes equipped with a 16-megapixel camera that can shoot imagery up to three centimeters per pixel resolution. The eBee drone’s battery allows it to fly for up to 45 minutes, so it can cover up to 10 square kilometers in a single flight. These images are then used to create maps with a precision of five centimeters.

In Haiti, Drone Adventures dispatched three eBees and mapped more than 45 square kilometers in less than a week. After each flight, SenseFly’s image processing software, Postflight Terra 3D, generated a georeferenced orthomosaic as well as a digital elevation model. These were then imported directly into ArcGIS for mapping and analysis. IOM and Drone Adventures also made the data freely available to any other agencies that could benefit from it.

IOM used this orthoimagery and 3D models to assess the damage done by Tropical Storm Sandy. Several dense shantytowns in Port-au-Prince were mapped, and this information was used to count the number of tents so a census could be taken of the population. This door-to-door blanket of the community is the intensive first step in identifying what aid is required by the population and deciding how best to organize more permanent infrastructure to service the ad hoc neighborhoods.

3D terrain models of ravine beds that were too dangerous to visit and map on foot were also created. These models are being used to perform water-flow simulations and help decide where to build infrastructure to mitigate flooding, a very important part of IOM’s mission in a country already ravaged by cholera.

IOM will continue to use ArcGIS software and the information gathered from the eBees to help improve water drainage and watershed management, conserving and enhancing forest cover, conserving soil, and mitigating hazards both through man-made structures and via the environment. For more information on how sensors are helping the mapping community, visit

Karen Richardson is a Senior Writer at Esri. She covers stories about the use of GIS for creating maps, data and charts including 3D, LiDAR and image data.

A 2.888Mb PDF of this article as it appeared in the magazine complete with images is available by clicking HERE