Impact of river basin morphology and climate on geomorphic scaling laws for floodplain mapping

Hydrogeomorphic scaling laws, providing consistent flood flow depth estimations as a function of contributing drainage areas, are widely used by DTM-based parsimonious floodplain delineation methods. Recent research demonstrated the suitability of hydrogeomorphic floodplain delineation models from basin to global scale across diverse climatic and morphological settings. However, distributed analysis of scaling laws performances in semi-arid to humid and low-gradient to steep basins are missing. In this work, we considered eleven basins in the west-central United States to assess flow depths – contributing areas scaling law parameters with varying basin slope and average annual rainfall. The outcomes of this scaling law parametrizationanalysis were used to test improved performances of the GFPLAIN hydrogeomorphic floodplain delineation model. Outcome of this work show improved performances and effectiveness of the GFPLAIN modelwith varying morphometric and climatic factors using as main input largely and freely available global climate and topographic datasets.