Understanding the Value and Function of Flood Inundation Mapping to Support Decision Support

Spatial gaps in Flood Inundation Mapping (FIM) coverage today and the need from emergency and water resource managers for event-driven FIM, led to the creation of the new National Water Model FIM – a high-resolution FIM that provides forecasts of flooding extent across the country developed by the National Water Center in coordination with National Weather Service (NWS) River Forecast Centers and Weather Forecast Offices. Initially rolled out in Texas and the Northeast U.S., the NWS aims to have an operational FIM for 100% of the US population by 2026, along with total water level FIM forecasts along the coasts.

FIMs are a common way to communicate flooding risk, but research is needed about how these products’ content and design can best support decision-making. A mixed-methods social science research study about FIM products available through the National Water Model, River Forecast Centers and National Water Prediction Service systems helps fill this need. Using focus groups and surveys for both professional stakeholders and the general public in the Mid-Atlantic River Forecast Center area (State College, PA and Binghamton, NY WFO areas) and the West Gulf River Forecast Center area (Houston WFO area), this research uses a scenario-based approach to lead participants through flooding events and explores how FIM products would help with decision-making in such events. Both quantitative and qualitative analysis from these sessions and surveys inform recommendations for product design and delivery and address questions related to barriers to use and understanding. In this presentation, we will describe the project’s objectives, approach, and findings related to use case descriptions for the kinds of decisions users will make with these maps, as well as recommendations for product design and use.