⚠️This is the first operational version of the handbook, but it is still a work in progress and will be heavily updated during 2024!⚠️

Risk assessment for river flooding

Risk assessment for river flooding#

Risk assessment methodology

In this workflow we will consider the potential impacts of river flooding. The flood risk is calculated by combining maps of potential river flood extent with exposure and vulnerability data in the form of economic damage functions for infrastructure. In particular, flood damage is calculated by applying damage curves to the flood inundation depth maps, taking into account the local situation. For each grid point, the damage is calculated based on the flood depth, land use type, damage curves, and country-specific parameters (can be defined by the user) that approximate the economic value of different land use types. The resulting data and maps help the user to assess the hotspots of potential economic damage due to river flooding for different return periods of high river flows.

Attention: The hazard (flood maps) data is pre-processed using the dedicated hazard assessment script. If you would like to use the provided hazard data and have not yet retrieved the necessary data using that script, please do so before using this risk assessment script (see Hazard_assessment_FLOOD_RIVER.ipynb).

Please note that the underlying flood map dataset does not include river flood defences that may already be in place. It is important to always check the result against existing local knowledge of the infrastructure. More information on the applicability of the dataset is found below.

Datasets

The following datasets are used in this workflow:

  • Flood maps: river flood extent and water depth: available from the Joint Research Centre for different return periods. The flood maps come at a resolution of 3 arc-seconds (30-75m in Europe depending on latitude). Additionally we use coarse-resolution flood maps (30 arc-seconds resolution) from Aqueduct Flood Hazard Maps dataset to assess qualitatively the change in river flood hazard under climate scenarios.

  • Land-use information: The land cover map is available from the Copernicus Land Monitoring Service.

  • Damage curves for infrastructure expressed as relative damage percentage (available here).

  • Data on economic value for different types of land use, which can be country/location specific. This data is specified in the Excel file provided on the GitHub repository of the workflow (see LUISA_damage_info_curves_template.xlsx)

Output of the workflow

The outputs of this workflow are:

  • Potential flood depth and extent maps for the area of interest for extreme events with different return periods.

  • Potential flood damage maps, expressed in economic value, for extreme events with different return periods.