Post-Event Urban Flood Mapping by Amateur Aerial Photography and Assessment of Potential Damage: Case of Fond du Lac, Wisconsin

Abstract

Several communities are so focused on the positive benefits of a rising economy that they ignore the negative effects of the urbanization process, such as the exacerbation of flooding by increasing impermeable surfaces. Even when a flooding disaster occurs, the communities? fear of another strike decreases over time along with its preparedness. For instance, on June 12, 2008, the city of Fond du Lac, Wisconsin, was blindsided by a major flood because many never knew that their residence was located in a flood-prone area. Most city roads were reported to be underwater and in some places bridges were even submerged by the Fond du Lac River. A lot of the damage was so severe that the Federal Emergency Management Agency (FEMA) awarded Fond du Lac more than $1.2 million to assist with repairs of homes and the city. As with the case of Fond du Lac, mapping flood prone areas can prepare potential victims and enforce local floodplain management policies. To accomplish this, FEMA launched the Map Modernization project, which aims to update the nation's flood maps. However, the agency is not able to do this alone and has decided to partner with local agencies to produce more accurate flood maps. Therefore, this project investigated the possibility of mapping urban flood areas from amateur aerial photographs and compared the resulting flood map to the most recent FEMA maps of the study area. On a broader level, the study updates the FEMA flood maps of Fond du Lac, Wisconsin, and the methodologies developed in this study can help similar cities across the nation adjust their flood maps.