Mapping the Extent of the Flood: What We Have Learned and How We Could Do Better

Much attention has been given to mapping the extent of a flood by using optical, radar, digital elevation model (DEM), and river gauge data. The mapped extent is often supported and verified by ground observations. The popularity of methods that use these data sets has arisen due to effectiveness, availability, and low cost. This paper summarizes the strengths and weaknesses of the individual and combined use of optical, radar, DEM, and river gauge data to map flood extent. The 1999 flood associated with Hurricane Floyd in eastern North Carolina is used as an example throughout the paper.