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.

Explore map Read paper
Animated map showing FEMA flood patterns in pale blue and model-generated flood extents in royal blue across Indiana terrain
FEMA pattern Model-generated extent

The problem—and the solution

The problem

Detailed flood maps take too long to build

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.

The solution

Deep learning completes the map

The model learns from existing FEMA flood patterns and terrain, then applies them where detailed studies do not exist—producing national, high-resolution flood information at a fraction of the time and cost.

National scale. High resolution. Low cost.

Read the method in the paper →

A national flood map is the proof

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.

Loading map
Open fullscreen

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.

Flood case study limitations
  • Shows fluvial and coastal 100-year flood extents; largely excludes rainfall-driven flooding.
  • This is a research product, not a regulatory map. For official decisions, consult the FEMA Map Service Center.
  • Accuracy varies by terrain (validation mIoU 0.48–0.54).