Continuous, large‐scale simulation model for flood risk assessments: proof‐of‐concept

Abstract

In this paper we present the Regional Flood Model (RFM), a process‐based model cascade developed for large‐scale basins. The objective of this study is to demonstrate that flood risk assessments, based on a continuous simulation approach, including rainfall–runoff, 1D river network, 2D hinterland inundation and damage estimation models, are feasible at the scale of large catchments. RFM is applied to the German part of the Elbe catchment including around 2700 river‐km. For this proof‐of‐concept study, simulations are performed continuously over the period of 1990–2003. Simplification of equations and parallelisation enable the continuous 2D hydrodynamic inundation simulation with reasonable run‐times on a relatively high resolution of 100 m. As uncertainties are introduced with each module along the model chain, results are evaluated, where possible, with observed data. Results indicate that uncertainties are significant, especially for hydrodynamic simulations. This is basically a consequence of low data quality and disregarding dike breach effects in the simulations. Reliable information on overbank cross‐sections and dikes is expected to considerably improve the results. We conclude that the large‐scale simulation of catchment processes, inundation and damage, driven by long‐term climate data, is viable within a continuous simulation framework. It has the potential to provide a spatially consistent, large‐scale picture of flood risk.

Social media as an information source for rapid flood inundation mapping

“…The spatial detail of the simulated inundation depths depends on the discretization level of the model setup which is usually below 100 m horizontal resolution (Horritt and Bates, 2002;Falter et al, 2014). The near-real-time application of hydrodynamic-numeric models is hampered by the need to provide appropriate estimates of initial and boundary conditions, to assimilate model simulations and observations (Matgen et al, 2007) and by considerable computational costs .…”

Impacts of spatial resolution and representation of flow connectivity on large-scale simulation of floods

“…Most of these studies identified the outputs from GHMs and GRMs as major sources of uncertainty. Falter et al (2016) specifically pointed to the uncertainties coming from discharge simulations and 1-D hydrodynamic simulations in river channels. Winsemius et al (2013) pointed out that more focus should be placed on studying the behavior of the GHMs and GRMs during extremes.…”

“…The modeling framework was implemented and validated in Bangladesh. A model cascade consisting of a regional rainfall-runoff model, a 1-D diffusive wave river routing model, and 2-D raster-based flood inundation model was used by Falter et al (2016) to simulate flood risks at the Elbe River. Dottori et al (2016) used the discharge outputs (available at 0.1 • resolution) from the model cascade of GloFAS (Alfieri et al, 2013) to calculate the discharge maxima at several return periods.…”

Generation of Spatially Heterogeneous Flood Events in an Alpine Region—Adaptation and Application of a Multivariate Modelling Procedure

“…As flood events in most cases are heterogeneous in space and time [4,5], the use of homogenous flood scenarios may lead to inaccurate results [6,7]. Therefore, heterogeneous flood scenarios, which take into account the spatial variability of flood events, should be considered in flood risk analysis [6,8,9].…”