Deep learning completes US flood hazard maps revealing millions exposed to previously unrecognized risk
Large-scale, high-resolution flood maps can take decades to build. Deep
learning completes them at a fraction of the time and cost, giving the
public access to crucial flood information that would otherwise remain
unavailable.
Large-scale, high-resolution flood maps can take decades and substantial
resources to produce. FEMA has detailed studies for only about one-third
of U.S. rivers, leaving many communities without equivalent information.
The solution
Deep learning completes the map
The model learns from existing FEMA flood patterns and terrain, then
applies those relationships where detailed studies do not exist. This
produces high-resolution flood information at national scale, at a
fraction of the time and cost.
FEMA pattern Model-generated extent
How the model completes the map
Existing FEMA flood patterns provide the training signal. Terrain provides
the physical context. The model learns the relationship between the two and
estimates flood extent where detailed maps are missing.
The light layer shows FEMA’s published 100-year flood extent. Blue shows
model-generated coverage created by applying learned spatial patterns across
the country.
Flood mapping demonstrates what the method can reveal
Applied across the contiguous United States, the method reveals 11.04 million
more people and 4.12 million more buildings within modeled 100-year flood
extents beyond FEMA’s published coverage.
FIG. 01 — EXPOSURE
Largest population gaps
Miami and New York have the largest additional exposed populations;
McAllen and Houma have almost no FEMA-mapped exposure.
FIG. 02 — POPULATION GAPS
Most undermapped metropolitan areas
Ranked by the share of exposed residents outside FEMA’s extent, among
metropolitan areas with at least 10,000 exposed people.
FIG. 03 — UNDERMAPPED METROS
From national scale to local detail
These city views show how the same national model produces locally detailed
spatial insight.