Brief communication: Hurricane Dorian: automated near-real-time mapping of the “unprecedented” flooding in the Bahamas using synthetic aperture radar

Diego Cerrai,Qing Yang,Xinyi Shen,Emmanouil N Anagnostou,Marika Koukoula

doi:10.5194/nhess-20-1463-2020

Abstract

Abstract. In this communication, we present application of the automated near-real-time (NRT) system called RAdar-Produced Inundation Diary (RAPID) to European Space Agency Sentinel-1 synthetic aperture radar (SAR) images to produce flooding maps for Hurricane Dorian in the northern Bahamas. RAPID maps, released 2 d after the event, show that coastal flooding in the Bahamas reached areas located more than 10 km inland, covering more than 3000 km2 of continental area. RAPID flood estimates from subsequent SAR images show the recession of the flood across the islands and present high agreement scores when compared to Copernicus Emergency Management Service (Copernicus EMS) estimates.

Highlights

Hurricane Dorian was the strongest Atlantic hurricane at landfall in terms of maximum sustained winds (185 mph, 83 m s−1), tied with the 1935 Labor Day Hurricane (Landsea et al, 2014)
We present the early results we delivered with the RAdarProduced Inundation Diary (RAPID) NRT automated system 2 d after Hurricane Dorian hit the Bahamas, just a few hours after synthetic aperture radar (SAR) data for the event became publicly available
We provide a short description of the methodology, and we detail the extent of flood inundation by analyzing RAPID maps

Summary

Introduction

Hurricane Dorian was the strongest Atlantic hurricane at landfall in terms of maximum sustained winds (185 mph, 83 m s−1), tied with the 1935 Labor Day Hurricane (Landsea et al, 2014). Neither precipitation nor coastal surge could be directly measured because of the lack of a ground-based observational network In this and other remote areas around the world where ground-based measurements are not available, precipitation can be assessed using near-real-time (NRT) satellite estimates available through the National Aeronautics and Space Administration (NASA) Global Precipitation Measurement (GPM) Integrated Multi-satellitE Retrievals for GPM (IMERG), version 06 (Huffman et al, 2019). As discussed in the Methodology section below, the system is triggered (Yang et al, 2019) by IMERG precipitation estimates (Huffman et al, 2019), and it processes Sentinel-1 SAR data In this brief communication, we present the early results we delivered with the RAPID NRT automated system 2 d after Hurricane Dorian hit the Bahamas, just a few hours after SAR data for the event became publicly available. We provide a short description of the methodology, and we detail the extent of flood inundation by analyzing RAPID maps

Methodology

Results

September – Grand Bahama

Closing remarks