Iso-flood severity mapping: a new tool for distributed flood source identification

Flood hazard increasingly threatens human communities that occupy floodplains. Economic planning of control measures relies on identification and prioritization of the flood source areas in the watershed draining to the threatened reach. Distribution of flood control activities in proportion to the priority of flood source areas can reduce excessive costs and increase flood control efficiency. In this research, a distributed Clark-based rainfall-runoff model in conjunction with a hydrologic routing model was calibrated and validated in the watershed of interest. Then, a 2 * 2 km<Superscript>2</Superscript> discretization scheme was implemented to represent some 200 pixels for flood source identification. The unit flood response (UFR) approach was then carried out at pixel scale. This step resulted in, for the first time, a distributed flood index map, which identifies and ranks pixels with high impact on the flood regime of the flood-threatened reach. The iso-flood severity map can be also extracted in a contour format. Copyright Springer Science+Business Media B.V. 2010