Google Earth Engine Implementation of the Floodwater Depth Estimation Tool (FwDET-GEE) for Rapid and Large Scale Flood Analysis

The Floodwater Depth Estimation Tool (FwDET) provides rapid-response floodwater depth estimations during time-sensitive flood events. Recently, modern cloud-computing advancements and platforms, such as Google Earth Engine (GEE), have further enabled the streamlining and scalability of large-scale geoprocessing. This letter presents a FwDET implementation in GEE (FwDET-GEE) that is open access, utilizes cloud-stored elevation data, and performs geospatial analytics on the fly. This tool offers an innovative solution for producing timely floodwater data during flood activations that require emergency response and post-flood assessment. Accuracy metrics were generated to validate the comparability of FwDET-GEE to FwDETv2.0, which used Python in ArcGIS. To demonstrate the geographic scalability of the model, both local- and region-scale flood events/systems were evaluated. This letter also highlights a use case wherein flooded areas are overlain with building footprint data to identify infrastructure at risk of damage.