The Story of Grassroots Mapping

When The Federal Aviation Authority imposed a no-fly zone last year over the BP oil spill in the Gulf of Mexico, major media organizations cried foul, but could do little to get around the restrictions. It was the biggest environmental disaster in U.S. history, and the media couldn’t get to the story.

But a small band of grassroots activists had other ideas.

(Photo: oil burning near Isle Grande Terre, June 10, 2010)

Using kites, cameras and helium balloons, volunteers from the Louisiana Bucket Brigade, a community environmental health organization, teamed up with the citizen mapping group Grassroots Mapping to take aerial photos of the spill.

"There was a huge number of people who wanted to get involved with the spill, and this was something we could offer," said Shannon Dosemagen (pictured right), oil spill response coordinator of the Bucket Brigade.

Each mapping kit cost $100 and gave them the equivalent of satellite mapping capabilities.

The methodology was developed by Jeffrey Warren of MIT's Center for Future Civic Media, who officially launched Grassroots Mapping in Jan. 2010. The group works to bring mapping tools to everyday citizens.

(Photo: a Grassroots Mapping kit. Click
for an illustrated user's guide)

The year before, Warren had worked with land-rights activists in Lima, Peru. They created maps of settlements in dispute to help residents gain legal claim to the land.

(Photo: Jeff Warren and local kids in Cantagallo, a settlement in Lima, Peru)

Although the maps were never used for legal purposes, they empowered the community as cultural and urban planning tools. The experience inspired Warren to launch the Grassroots Mapping network.

(Photo: a finished map of Cantagallo).

Unlike satellites, which fly miles above the earth, kites and balloons can map from 500 feet in the air. The resulting images have up to 100x the spatial resolution of Google or Yahoo Maps.

(Photo: a picture taken by a Grassroots Mapping kit. The kite string is visible as a green line in the upper left-hand corner.)

Individual pictures get stitched together into larger maps, and all images are released to the public domain.

(Photo: Isle Grande Terre on May 27, 2010).

On May 9, 2010, the oil spill had yet to reach the coast. The Gulf Coast mappers took a boat to the Chandeleur Islands, about 50 miles south of the Louisiana shore.

"I could see the oil coming in through the breaks in the barrier islands," said volunteer Stewart Long. "You could see the dispersants in the water. It smelled bad, it looked kind of like pond scum, or pollen. It was everywhere."

(Photo: one of the Chandeleur Islands on June 9, 2010)

The volunteers began by setting the camera to snap continuous pictures once every second. They anchored the camera to a rig (a soda bottle) and tied it to the balloon.

After releasing the balloon, the team cut the engine and let the boat drift with the wind.

(Photo: Stewart Long, right, prepares to release a weather balloon/camera rig)

Traditional aircraft were banned from flying lower than 4,000 feet above the spill, but the restrictions didn't affect tethered kites or balloons.

These photos, taken from a balloon at 1,500 feet, may be the clearest images of the Chandeleur Islands on May 9.

Since May 2010, volunteers have created over 40 additional maps of the coast.

(Photo: the Chandeleur Islands on May 18)

Grand Island State Park, Louisiana on June 3. Note the orange boom along the beach.

Waveland, Mississippi on June 10, weeks after the oil made landfall.

Lake Borgne, Louisiana on June 11.

Port Sulfur, Louisiana on July 11. The oil is visible as a brown line along the coast.

Long, a geographer by training, processed many of the photos by stitching them together. Some of the cameras were rigged with GPS devices that tracked their flight path (see yellow pinpoints). Long also used existing images (such as Google maps) as a guide.

Click for a video of Long's process.

Ft. Morgan, Louisiana on Aug. 15, overlaid on Google Earth.

The final processed maps may be used in future litigation or environmental monitoring.

"I hope it creates a different data set, one that's not just relying on the perceived experts (like) scientists or the data BP is pushing out," said Dosemagen. "This is an alternative source ...[for] community members, environmentalists and activists."

Photos courtesy of

Louisiana Bucket Brigade
Stewart Long/GonzoEarth
Cesar Harada
Jeff Warren
Adam Griffith
Grassroots Mapping