Subsidence Sentinel — Coastal Cities Sinking

Map Layers

Subsidence Rate Zones (research-derived)

FEMA Flood Zones ✓ real data

SLR Projection Zones (SRTM-derived)

Critical Infrastructure ✓ real data (OSM)

Critical: >20 mm/yr — Katy hotspot

High: 10–20 mm/yr

Moderate: 5–15 mm/yr

Low: 3–5 mm/yr (geological background)

Stable / Rebound (regulated areas)

Stabilized (historical: up to 3 m cumulative)

VE — Coastal High Hazard (100-yr + waves)

AE — Special Flood Hazard (100-yr flood)

A — Special Flood Hazard (no BFE)

Tier 1 (<50 cm rise)

Tier 2 (50–120 cm)

Tier 3 (120–200 cm)

Sea Level Measurements & Projections Galveston Pier 21 (NOAA Station 8771450)