The Global Flood Awareness System (GloFAS) – Overview of Recent Developments

Abstract:

The Global Flood Awareness System (GloFAS) is an ensemble river discharge forecasting system developed and maintained jointly between the European Commission - Joint Research Centre (JRC) and the European Centre for Medium-range Weather Forecasts (ECMWF). The system consists of a cascade of two models, where the surface and sub-surface runoffs are computed by the Hydrology revised Tiled ECMWF Scheme for Surface Exchange over Land (HTESSEL) while the runoff routing and other hydrodynamic components are modeled by the LISFLOOD model. Since its set up in July 2011, GloFAS has been producing probabilistic discharge forecasts on daily basis at 0.1^o spatial resolution with global coverage. The system is undergoing some updates that focus on the improvement of the hydrodynamic model, which include incorporation of an updated river network and river width maps, inclusion of lake and reservoir modules and a better representation of transmission losses. Additionally, a new web interface and web service for communication and visualization of the discharge forecast has been developed. Finally, the use of ECMWF re-forecasts as reference climatology to derive flood warning thresholds in comparison to those of ERA-Interim has also been assessed. In this work we present: 1) an overview of recent advances of GloFAS, 2) the results of an evaluation study which used ECMWF re-forecasts to derive global flood warning thresholds and 3) the role of the GloFAS in the recently launched Global Flood Partnership (GFP).