GloFAS Next: Towards hyper-resolution flood forecasting at global scales
Authors: Stefania Grimaldi(1), Carlo Russo(3), Ervin Zsoter(2), Peter Salamon(1), Cinzia Mazzetti(2), Christel Prudhomme(2), Corentin Canton De Wiart(2), Margarita Choulga(2), Damien Decremer(2), Juliana Disperati(1), Francesca Moschini(2)
(1) European Commission, Joint Research Centre, Ispra, Italy,
(2) European Centre for Medium-Range Weather Forecasts, Reading, UK
(3) Unisystems Luxembourg Sàrl
The Global Flood Awareness System (GloFAS) is a freely available flood forecasting service that is running fully operational as part of the Copernicus Emergency Management Service since April 2018. GloFAS offers a range of forecast products which are tailored to give a quick overview of current and future hydro-meteorological situation, and of the ongoing and upcoming flood events.
The aim of GloFAS is twofold: on the one hand to provide countries, i.e. national and regional authorities and services that have no or only limited flood forecast capacity with complementary, up-to-date flood forecast information for large (trans-national) river basins, and on the other hand to support international organizations such as e.g. the UN or the International Federation of Red Cross and Red Crescent Societies with forecast-based financing in decision making and preparatory measures before major flood events.
GloFAS products are generated using the open source hydrological model called LISFLOOD. LISFLOOD is an open-source, distributed, physically based rainfall-runoff model able to represent all the main hydrological processes: partition of precipitation into rain and snow, snow melting, canopy interception of rain, water infiltration into the soil, groundwater storage, surface runoff, lakes, dams, irrigation and other human water uses, flow in the rivers and in the floodplains. A set of maps showing the terrain slope, soil properties, land cover and land use features, allows to account for the morphological, physical, and land use characteristics of catchments and thus provide a more accurate representation of the rainfall-runoff processes in different climates and socio-economic contexts.
This presentation focuses on the upcoming major upgrade of the currently operational GloFAS set-up (v 3.1). Specifically, the spatial resolution of the entire system is doubled from 0.1 degrees (~10 km) to 0.05 degrees (~5km) which will allow a more detailed representation of the river network and of the spatial variability of catchments’ characteristics. A crucial feature of the upgrade is the use of the latest research findings and remote sensing datasets to prepare a set of completely revamped maps that are required as input for LISFLOOD. Examples include the latest land cover information and leaf area index layers from the Copernicus Global Land Service, global hydrology datasets based on MERIT Hydro (Yamazaki et al. 2019) or global soil data from ISRIC. The new set of maps together with a completely new hydrologic model calibration incorporating more than 1800 gauging stations will lead to more physically based parameters and to more accurate flood forecasts. The pre-operational release of the high resolution GloFAS set-up is planned for the end of 2022.