A multi-source 120-year U.S. flood database with a unified commonformat and public access

Abstract. Despite several flood databases available in the U.S., there is a benefit to combine and reconcile these diverse data sources into a comprehensive flood database with a unified common format and easy public access in order to facilitate flood-related research and applications. Typically, floods are reported by specialists or media according to their socioeconomic impacts. Recently, data-driven analysis can reconstruct flood events based on in-situ and/or remote-sensing data. Lately, with the increasing engagement of citizen scientists, there is the potential to enhance flood reporting in near-real-time. The central objective of this study is to integrate information from seven popular multi-sourced flood databases into a comprehensive flood database in the U.S., made readily available to the public in a common data format. Natural Language Processing, geocoding, and harmonizing processing steps are undertaken to facilitate such development. In total, there are 695,808 flood records in the U.S. from 1900 to the present. The database features event locations, durations, date/times, socioeconomic impacts (e.g., fatalities and economic damages), and geographic information (e.g., elevation, slope, contributing area, and land cover types retrieved from ancillary data for given flood locations). Finally, this study utilizes the flood database to analyse flood seasonality within major basins, and socioeconomic impacts over time. It is anticipated that thus far the most comprehensive yet unified database can support a variety of flood-related research, such as a validation resource for hydrologic or hydraulic simulations, hydroclimatic studies concerning spatiotemporal patterns of floods, and flood susceptibility analysis for vulnerable geophysical locations. The dataset is publicly available with the following DOI: https://doi.org/10.5281/zenodo.4547036 .