Point at a basin to see its numbers.
How this was made
Sentinel-2 imagery gives burn severity, a 10 m USGS elevation model gives
slope and drainage, and the USDA soil survey gives erodibility. Those three
feed the USGS M1 model, which returns the rainfall each basin needs for a
50% chance of producing a debris flow.
The model implementation matches the official USGS package exactly, and
reproduces the published USGS assessment for the Bridge Fire to floating
point precision when given their inputs. Three of the fires here have been
compared against field-mapped soil burn severity, and on all three this
pipeline runs conservative: it over-warns rather than under-warns.
A fire that BAER has not yet assessed still gets a map, because the
rainfall that matters arrives before the field survey does. Those fires are
labelled, and their numbers carry an uncertainty range but no accuracy
check.
"High" means at least a 60% chance, which is where the top two of the
five likelihood classes USGS publishes begin.
Code and
full method
Not an operational warning product.
This is a portfolio project. It reproduces a published USGS model from
public data and has not been reviewed or endorsed by USGS, CAL FIRE, the US
Forest Service or any other agency. Nothing here predicts whether a
particular canyon will produce a debris flow, and it must not be used for
evacuation, access or any other safety decision. For official post-fire
hazard information see the
USGS Landslide Hazards Program
and your county emergency management agency.