Seeing Floods from Space: How Sentinel-1 Helps Map Floods in New York City

Abstract

Flood susceptibility maps are highly effective tools for identifying and mitigating areas at risk of flooding, but they require extensive historical flooding data from either in-situ or remote sensing data collection. This study demonstrates how publicly available Sentinel-1 Synthetic Aperture Radar (SAR) imagery can be used to generate flood maps for New York City’s five boroughs. Sentinel-1 provides high spatial, geometric, and radiometric resolution, making it ideal for detecting surface water under all weather conditions. Using the European Space Agency’s Sentinel Application Platform (SNAP) for data pre-processing and QGIS and Google Earth Pro for visualization, we processed and analyzed Sentinel-1 data to identify flood-prone zones. The results highlight Sentinel-1’s effectiveness as a low-cost, reliable resource for urban flood analysis and demonstrate its potential for supporting flood monitoring and resilience planning in major metropolitan areas like New York City.