Beyond Flood Extent: Augmenting Near-real-time Remote Sensing with Water Depth and Impact Assessment Tools

Abstract:

Remote sensing analysis is now routinely used to map flooding extents in retrospective and near-real-time applications. Such products are highly valuable for emergency respondence as they can offer continued observational information about the flood extent over large geographical domains. Emerging cloud- and web-based geospatial tools provide the datasets and resources to rapidly calculate and disseminate flood impact analyses; thereby coupling remote sensing information and impact assessment tools as a force multiplier for flood emergency response. Here we present a new implementation of the Floodwater Depth Estimation Tool (FwDET) and two ongoing uses of the tool in flood response and flood analysis scenarios. FwDET utilizes geospatial methods applied to DEM and flood extent data to estimate floodwater depth. Recently, this method was ported to Google Earth Engine (FwDET-GEE) thereby streamlining the pre-processing, execution, and result dissemination stages. First, usage of FwDET-GEE during Global Flood Partnership (GFP) response activations will be highlighted. Building footprint data is used to provide a synoptic analysis and quantitatively visualize flood impact. Second, a large-scale flood impact assessment for the State of Alabama is described. In the latter study, FEMA 100-year flood maps, 10m NED DEM data, and Microsoft Building Footprints are used to assess flood susceptibility.