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The following is a description of the latest operational release of EFAS v4 v5.60. For an overview of other EFAS releases, please see: EFAS versioning system.

Summary

EFAS v4v5.6 introduces minor 0 introduces a number of major changes to the system, as well as some general bug fixes. Here is a summary of the main changes: 

1. New version of LISFLOOD

LISFLOOD version 3.2.0 is used in this EFAS release. It includes important developments, such as:

• enhanced code capability to handle inputs;
• new netCDF readers based on xarray that allow for more flexibility and efficiency, dramatically decreasing the time required to load large inputs thus leading to improved computational performances;
• extensive use of unit tests to verify the functioning of the model and enhance collaborative development of the code;
• improvements of the management of latitude and longitude grids to allow maximum precision of the reference system;
• porting of the code to python3.

The modelling of the hydrological processes has not changed compared to the version of the model used in the previous EFAS release.

For more information, please visit the dedicated GitHub space: https://github.com/ec-jrc/lisflood-code/releases

2. Rapid Risk Assessment layers

• The code used to generate the rapid risk assessment layers has been rewritten using python 3 and was integrated to the general product generation framework.
• In the Rapid Impact Assessment layer, the information which appears in the pop out window when a shaded region is clicked has been reformatted:
  • Exposure information appears within a first table which summarises the population, road network and landcover potentially affected.
  • A second table summarises the flood event information, including the start and of the flooding based on the forecast median and mean exceedance probabilities for different return period thresholds.
• In the Rapid Flood Mapping layer, the inundation extent now corresponds to the unprotected scenario which does not consider the role of flood defences. Previously the layer showed the inundation extent when considering the role of flood defences.

3. COSMO-LEPS

• The EFAS suite has been modified to automatically detect an outage of the provision of the COSMO-LEPS forecasts
• In this situation the reporting points product and associated products will proceed without the COSMO-LEPS forecasts
• The ERIC flash flood forecasts will not be produced as they rely solely upon the provision of the COSMO-LEPS forecasts

Technical details

including:

• a higher spatial resolution. EFAS v5.0 has 1 arcmin/ 0.0166667 degrees resolution (~1.4km), as opposed to all the previous EFAS versions having 5-km resolution.
• a different project system, now based on EPSG4326 instead of ETRS89 Lambert Azimuthal Equal Area Coordinate Reference System (ETRS-LAEA) for previous versions.
• a larger modelling domain whose extension has been enlarged to match the river catchments. 
• an entirely new set of 0.0166667 degrees resolution input maps produced using the most recent research findings, remote sensing, and in-situ datasets.
• major improvements to the open-source hydrological model LISFLOOD.
• a new calibration at 1903 in-situ gauging stations, with a parameter regionalisation performed to estimate the parameters of catchments for which in situ discharge observations were not available.
• newreturn period thresholds and snow water/soil moisture anomaly maps based on a climatology from 1992 – 2022. The EFAS v5.0 river discharge climatology is available at the C3S Climate Data Store.
• updated hydrological post-processing models, recalibrated for EFAS v5.0.
• new flood hazard maps, generated using LISFLOOD-FP at 90m resolution and MERIT hydro DM and EFAS v5.0 reference dataset
• new reforecast configuration (medium-range), with the hydrological reforecast datasets being generated during the operational processing chain
• ERIC based on LISFLOOD surface runoff outputs instead of empirical relationships
• ERIC notification points and reporting points shown only for catchments below 1000km²
• additional flood event information available in the Rapid Impact Assessment pop-out table (see EFAS Rapid Flood Mapping and Rapid Impact Assessment)
• updated exposure information used in Rapid Impact Assessment (see CEMS-Flood flood impact forecasting)
• an updated major rivers layer (see Static Layers Overview)
• new rules for defining dynamic reporting points (see EFAS v5.0 - Dynamic Reporting Points)

This upgrade of EFAS has large impacts on the EFAS modelling results.

Other smaller changes include the adjustment of the temperature evolution graph in the reporting point window, which was corrected to show the average temperature of the whole catchment.

Technical details