Uncertainty in Flood Inundation Mapping: Current Issues and Future Directions

This paper presents key issues associated with uncertainty in flood inundation mapping. Currently flood inundation extent is represented as a deterministic map without consideration to the inherent uncertainties associated with various uncertain variables (precipitation, stream flow, topographic representation, modeling parameters and techniques, and geospatial operations) that are used to produce it. Therefore, it is unknown how the uncertainties associated with topographic representation, flow prediction, hydraulic model, and inundation mapping techniques are transferred to the flood inundation map. In addition, the propagation of these individual uncertainties and how they affect the overall uncertainty in the final flood inundation map is not well understood. By using a sample data set for Strouds Creek, N.C., this paper highlights key uncertainties associated with flood inundation mapping. In addition, the idea of a probabilistic flood inundation map is articulated, and an integrated framework approach that will connect data, models, and uncertainty analysis techniques in producing probabilistic flood inundation maps is presented.