Application of PlanetScope Imagery for Flood Mapping: A Case Study in South Chickamauga Creek, Chattanooga, Tennessee

Floods stand out as one of the most expensive natural calamities, causing harm to both lives and properties for millions of people globally. The increasing frequency and intensity of flooding underscores the need for accurate and timely flood mapping methodologies to enhance disaster preparedness and response. Earth observation data obtained through satellites offer comprehensive and recurring perspectives of areas that may be prone to flooding. This paper shows the suitability of high-resolution PlanetScope imagery as an efficient and accessible approach for flood mapping through a case study in South Chickamauga Creek (SCC), Chattanooga, Tennessee, focusing on a significant flooding event in 2020. The extent of the flood water was delineated and mapped using image classification and density slicing of Normalized Difference Water Index (NDWI). The obtained results indicate that PlanetScope imagery performed well in flood mapping for a narrow creek like SCC, achieving an overall accuracy of more than 90% and a Kappa coefficient of over 0.80. The findings of this research contribute to a better understanding of the flood event in Chattanooga and demonstrate that PlanetScope imagery can be utilized as a very useful resource for accurate and timely flood mapping of streams with narrow widths.