Hazard maps with differentiated exceedance probability for flood impact assessment

Abstract

Abstract. In operational flood risk management, a single best-model is used to assess the impact of flooding, which might misrepresent uncertainties in the modelling process. We have used quantified uncertainties in flood forecasting to generate flood hazards maps that were combined based on exceedance probability scenarios. The purpose is to differentiate the impact of flooding depending on the building use. The aim of the study is thus to develop a novel methodology that uses a multi-model combination of flood forecasting models to generate flood hazard maps with differentiated exceedance probability. These maps take into account uncertainties steaming from the rainfall-runoff generation process and could be used by decision-makers for a variety of purposes in which the building use plays a significant role, e.g. flood impact assessment, spatial planning, early warning and emergency planning.

Reducing uncertainties in flood inundation outputs of a two-dimensional hydrodynamic model by constraining roughness

“…For advanced users such as decision makers in water management authorities, the uncertainty assessment should further serve as a tool for enhanced risk assessment. In addition, by visualizing inundation scenarios, improved flood mitigation and flood forecast planning strategies can be developed using a multi-model ensemble (Bhola et al, 2019) and potential damage can be estimated for various quantiles.…”