Buffalo National River Water Resources: Delineating 100- and 500-year Floodplains to Aid in Riverbank Management Along the Buffalo National River in Northern Arkansas

The Buffalo National River in Northern Arkansas, the country’s first national river, is susceptible to flooding due to the climate and geography of the Ozark Mountains region. The National Park Service (NPS) at the Buffalo National River has thus far estimated regulatory flood zones using data from 1987 that is likely outdated. These estimates are supplemented with anecdotal experiences which are likely imprecise. This project leveraged advancements in Earth observation, hydraulic modeling, and topographic analysis to produce 100- and 500-year floodplain maps and a 21-year (2004-2024) floodplain timeseries of key sites along the river to determine flood susceptibility. The hydraulic model outputs, validated by Landsat 5 & 7 imagery, will be beneficial to the NPS at the Buffalo National River for park planning, resource management, and program implementation relevant to flood impact mitigation. For analysis, the team also retrieved data from the European Space Agency, Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 Multispectral Instrument (MSI). This project served as a feasibility study which aimed to generate accurate and up-to-date floodplain maps for the Buffalo River and validate these resources using Earth observations. To assess the viability of these maps, the team utilized satellite imagery to test the accuracy of the 21-year timeseries outputs, which confirmed that the newly generated floodplain maps possess moderate to substantial agreement with the observed extents. Further efforts can be made to replicate the floodplain modeling procedure for other river bodies under the jurisdiction of the NPS and to augment the model with additional hydraulic controls.