Development of methodology for assessment of long‐term morphodynamic impact on flood hazard

Abstract

Abstract A methodology for quantification of the impact of sediment transport on flood hazard is proposed. The applied algorithm consists of several Python scripts for automation of sediment routing, hydrodynamic simulations, and geoprocessing of results. Flood hazard maps are uniquely linked with particular simulations of morphological changes in a river. Finally, the maps are stochastically processed. The proposed procedure was applied for a selected reach of the Warta river, located in Poland. Simulations were run for 6‐ and 12‐year flow series composed randomly on the basis of historical data. The 30 flow series for each period and four functions describing the transport of sediment were treated as uncertain variables. It was assumed that the features characterising the mean sample may properly represent the sediment content in the river reach studied. The final results are presented as maps showing the probabilities of inundation. The comparison of results with literature data confirmed the significance of the impact related to sediment transport processes on the quantification of flood hazard uncertainty. The main advantages of the presented algorithm are effective management of simulations and processing of results obtained in 240 runs of the sediment routing model.

Keywords

• flood hazard assessment
• flood mapping
• modelling of sediment transport
• python scripting