Interactive map provides Delta Fire information

Skye Kinkade, GateHouse Media California
A screen shot taken around noon on Thursday afternoon, Sept. 6, 2018, reveals the Delta Fire, center, had burned more than 15,000 acres. It also shows thermal “hot spots” that were detected by NASA satellites as far west as Cedar Creek and Plummer Hill near Trinity Lake. Photo contributed by Paul Doherty

An interactive online map showing the Delta Fire can give north state residents a better idea of where the fire is burning geographically.

Sourced with publicly available data, the map is not an evacuation map, and should be used for general reference only, according to its creator, Paul Doherty.

As of Monday morning, Sept. 10, 2018, the Delta Fire had burned more than 47,000 acres and was reported to be 5 percent contained.

Doherty, a Program Manager for the National Alliance for Public Safety GIS, explained that the map was created with publicly available information and is constantly updated from verifiable government sources.

For example, the small red dots on the map are thermal “hot spots” identified by NASA’s MODIS satellite, said Dr. Cassie Hansen, an Atmospheric Science GIS specialist and instructor at College of the Siskiyous.

Clicking on an individual hot spots on the map will bring up information about that particular location, specifying the report date and time.

Hansen said MODIS passes over about twice daily, and those spots will be updated as information comes in from NASA, usually two to four hours after the satellite overpass.

Doherty specified the hot spots are an estimated location with a leeway of a kilometer in all directions and is “subject to occasional errors where it will show heat where there is none, and vice versa.”

“Sometimes, the fire’s plume, or header, gets so hot that the satellite maps where it thinks it is on the ground. That’s just the nature of the data,” Doherty said. However, the hot spots are monitored by firefighting agencies and are helpful to visualize what direction the fire may be moving.

The map also incorporates incident data from Caltrans, including real-time cameras along Interstate 5 and road closures, and locations of shelters for displaced people.

Prominent on the map is wildfire activity from the U.S. Geological Survey. This would include active fire reports and the perimeters of U.S. fires, which are pulled together by the USGS.

The wildfire perimeters are the estimated burned area determined by the incident management team, Doherty said. “These are generally based on overnight observations from aircraft with infrared sensors, but ... update each day for large fires around 11:30 a.m.”

“Every fire gets mapped, and that information is published publically,” said Doherty, who works remotely for the non-profit Washington D.C.-based NAPSG from Boulder, Colo.

His map simply pulls available information together from a variety of different sources.

After maps such as his are created, they can be adopted by local agencies for official use. This was the case for the City of Redding’s informative Carr Fire map, said Hansen.

Hansen calls Doherty’s Delta Fire map a “live dynamic web map,” since it incorporates live data and can be manipulated by zooming in and out. There are also other views available, including a 3-D view, which is especially helpful for those trying to visualize the terrain in which the fire is burning.

The map should not be used to judge when evacuation is necessary, said Doherty.

“If you are told to evacuate, then go! Do not rely on this map as an excuse to ignore an order to evacuate,” he said.

Follow this link to access the map.