Authors: Sam Oldham, Lyle Prince, Taylor Miskin, Louis Rosas, Karina Larco, Jim Nelson, Riley Hales – Brigham Young University
Title: Expanding the Impact of the NWM FIM Capability by Adding Other Hydraulic Model Outputs
Abstract: The National Water Center has a mandate to provide flood inundation maps (FIM). This is currently done using the Height Above Nearest Drainage (HAND) method. HAND FIM maps are computationally and practically more feasible to develop, calibrate, and generate than most hydraulic models. 1D and 2D hydraulic models are usually confined to smaller areas and focus on specific features, such as bridges, which are poorly represented by HAND FIM. In addition to engineering hydraulic models, other methods using satellite imagery and statistical methods are becoming more common. Each method or specific model instance may be more accurate, model specific scenarios, or use different source datasets which make them a useful complement or replacement for HAND FIM in some situations. We propose a database and visualization tool that enables users to view an ensemble of models, regardless of their source methods and datasets, to enhance the existing HAND FIM capability of the National Water Model. The database stores metadata describing each submitted FIM based on relevant properties such as modelling methods, data sources, software, range of flows simulated, model developer, contact information, and the date it was created. Each FIM is indexed to one or more reaches of the National Water Model. To populate an initial database, we standardized a process to extract data from HEC RAS-2D and SRH-2D models retrieved from state transportation offices and the Army Corp of Engineers. Our database assists local governments and other parties responsible for disaster response. The maps are viewable in a web application and facilitate better FIM predictions to minimize the impacts of flooding.