Fire Line

The problem

One layer, the whole country, and three surprises

The National Interagency Fire Center publishes current wildfire incidents as an ArcGIS hosted feature service that anyone can query, and one request returns the whole country. The hard part is what is inside it: fires that are listed but no longer burning, fires counted twice, and numbers that were never reported.

Watch it work

Episode 6 — Fire Line (6:08)

Two public layers end to end: where the wildfire and perimeter data live, the three details that cost the most time, and the map they turn into.

What it covers

Two layers, three details, one map

• The layers: one query to the NIFC WFIGS current incident locations layer returns the whole country — about 1.4 MB on the day the episode was recorded — and the same layer answers statistics on the server, so a total by state is one small request. The current perimeter layer holds each fire’s mapped outline, joined to its incident by an ID; on the recording day there were 148 perimeters for 381 wildfires. Fire Line reads both every five minutes.
• Detail one, a current fire is not always burning: a fire stays in the layer until it is formally declared contained, controlled or out, or until clean-up rules drop it after 3, 8 or 14 days without an update. On the recording day 73 fires showed 100 percent contained and were still listed, and 53 had been discovered more than 90 days earlier.
• Detail two, one fire can be counted twice: the layer mixes wildfires, planned burns and complexes, and a complex’s member fires also appear as their own rows. Adding up the layer counted 19 member fires — about 531 thousand acres, roughly 15 percent of the national total — twice. Fire Line draws planned burns separately, counts each complex’s acres once, and says so in the panel.
• Detail three, many numbers are missing: percent contained was blank on 221 of 381 wildfires and size on 44. A blank is not a zero, so Fire Line says not reported and draws a blank in neutral gray, not in the red that means uncontained.
• How it becomes a map: every wildfire is a circle sized by acres on a log scale and colored by containment, planned burns are teal squares, perimeters carry an ember fill, a state filter and size chips narrow the map, the list sorts by largest, newest or most crewed, a member fire’s card names its complex, and a 3D view stands each perimeter up as a prism whose height is a symbol of size, not a measurement.

What it does not do

• Not for evacuation, suppression or safety decisions — those belong to your local emergency management and to InciWeb.
• No fire history — Fire Line shows the fires in the current layers, not past seasons.
• Not every fire has a perimeter — most fires are a single point until a perimeter is mapped.

Where the data comes from

Every source in the episode

• NIFC WFIGS Current Wildland Fire Incident Locations (ArcGIS hosted feature layer) — arcgis.com/home/item.html?id=4181a117dc9e43db8598533e29972015
• REST endpoint — services3.arcgis.com/T4QMspbfLg3qTGWY/arcgis/rest/services/WFIGS_Incident_Locations_Current/FeatureServer/0
• NIFC WFIGS Current Interagency Fire Perimeters — arcgis.com/home/item.html?id=d1c32af3212341869b3c810f1a215824
• REST endpoint — services3.arcgis.com/T4QMspbfLg3qTGWY/arcgis/rest/services/WFIGS_Interagency_Perimeters_Current/FeatureServer/0
• InciWeb, incident information — inciweb.wildfire.gov/
• Source sheet with every endpoint — allthingsspatial.io/pages/sources.html

The wildfire data is published by the National Interagency Fire Center and credited to its interagency partners. The provider publishes it with no warranty as to its accuracy, reliability or completeness and notes that it is not a legal document. The credit and that warning sit in the Fire Line footer and its About dialog.