EFAS Bulletins Yearbook 2006

The EFAS bulletins yearbook 2006 gives an overview for the year 2006 of EFAS events, news and EFAS-performance. IT gives an overview of all external EFAS alert reports in 2006. It collects all EFAS bulletins of this year.JRC.H.7-Land management and natural hazard

The Benefit of Probabilistic Flood Forecasting on European Scale Results of the European Flood Alert System for 2005/2006

Results of the European Flood Alert System for 2005/2006JRC.H.7-Land management and natural hazard

EFAS Bulletins Yearbook 2007

The EFAS bulletins yearbook 2007 gives an overview for the year 2007 of EFAS events, news and EFAS-performance. It gives an overview of all external EFAS alert reports in 2007 as well as a quick overview of the new EFAS-IS web service. It collects all EFAS bulletins of this year.JRC.H.7-Land management and natural hazard

The European Flood Alert System EFAS - Part 2: Statistical Skill Assessment of Probabilistic and Deterministic Operational Forecasts

Since 2005 the European Flood Alert System (EFAS) has been producing probabilistic hydrological forecasts in pre-operational mode at the Joint Research Centre (JRC) of the European Commission. EFAS aims at increasing preparedness for floods in trans-national European river basins by providing medium-range deterministic and probabilistic flood forecasting information from 3 to 10 days in advance, to national hydrometeorological services. This paper is Part 2 of a study presenting the development and skill assessment of EFAS. In Part 1, the scientific approach adopted in the development of the system has been presented, as well as its basic principles and forecast products. In the present article, two years of existing operational EFAS forecasts are statistically assessed and the skill of EFAS forecasts is analysed with several skill scores. The analysis is based on the comparison of threshold exceedances between proxy-observed and forecasted discharges. Skill is assessed both with and without taking into account the persistence of the forecasted signal during consecutive forecasts. Skill assessment approaches are mostly adopted from meteorology and the analysis also compares probabilistic and deterministic aspects of EFAS. Furthermore, the utility of different skill scores is discussed and their strengths and shortcomings illustrated. The analysis shows the benefit of incorporating past forecasts in the probability analysis, for medium-range forecasts, which effectively increases the skill of the forecasts.JRC.A.1-Work programme E

The European Flood Alert System - Part I: Concept and Development

Abstract This paper presents the development of the European Flood Alert System (EFAS), which aims at increasing preparedness for floods in trans-national European river basins by providing local water authorities with medium-range and probabilistic flood forecasting information 3 to 10 days in advance. The EFAS research project started in 2003 with the development of a prototype at the European Commission Joint Research Centre (JRC), in close collaboration with the national hydrological and meteorological services. The prototype covers the whole of Europe on a 5 km grid. In parallel, different high-resolution data sets have been collected for the Elbe and Danube river basins, allowing the potential of the system under optimum conditions and on a higher resolution to be assessed. Flood warning lead-times of 3-10 days are achieved through the incorporation of medium-range weather forecasts from the Deutscher Wetterdienst (DWD) and the European Centre for Medium-Range Weather Forecasts (ECMWF), comprising a full set of 51 probabilistic forecasts from the Ensemble Prediction System (EPS) provided by ECMWF. The ensemble of different hydrographs is analysed and combined to produce early flood warning information, which is disseminated to the hydrological services that have agreed to participate in the development of the system. In Part I of this paper, the scientific approach adopted in the development of the system is presented. The rational of the project, the system¿s set-up, its underlying components, basic principles and products are described. In Part II, results of a detailed statistical analysis of the performance of the system are shown, with regard to both probabilistic and deterministic forecasts.JRC.H.7-Land management and natural hazard

The European Flood Alert System - Part 1: Concept and Development

This paper presents the development of the European Flood Alert System (EFAS), which aims at increasing preparedness for floods in trans-national European river basins by providing local water authorities with medium-range and probabilistic flood forecasting information 3 to 10 days in advance. The EFAS research project started in 2003 with the development of a prototype at the European Commission Joint Research Centre (JRC), in close collaboration with the national hydrological and meteorological services. The prototype covers the whole of Europe on a 5 km grid. In parallel, different high-resolution data sets have been collected for the Elbe and Danube river basins, allowing the potential of the system under optimum conditions and on a higher resolution, to be assessed. Flood warning lead-times of 3-10 days are achieved through the incorporation of medium-range weather forecasts from the Deutscher Wetterdienst (DWD) and the European Centre for Medium-Range Weather Forecasts (ECMWF), comprising a full set of 51 probabilistic forecasts from the Ensemble Prediction System (EPS) provided by ECMWF. The ensemble of different hydrographs is analysed and combined to produce early flood warning information, which is disseminated to the hydrological services that have agreed to participate in the development of the system. In Part I of this paper, the scientific approach adopted in development of the system is presented. The rational of the project, the system¿s set-up, its underlying components, basic principles, and products, are described. In Part II, results of a detailed statistical analysis of the performance of the system are shown, with regard to both probabilistic and deterministic forecastsJRC.H.7-Land management and natural hazard

Summary Report of the 1st Workshop on the use of Ensemble Prediction System in Flood Forecasting (Ispra, 21-22 November 2005)

The first workshop on the use of EPS in flood forecasting was organised by the Joint Research Centre together with researchers from King's College in London (UK) and the Lancaster University (UK). The workshop was organized to address two main concerns of EFAS regarding flood forecasting based on EPS: 1. How to extract meaningful information from the meteorological EPS for medium-range flood forecasting? 2. How to communicate the uncertainty in flood forecasting to end-users? The specific objectives of the workshop were to explore together with flood forecasting experts from the Member States: 3. The usefulness of EPS information implemented in EFAS for operational flood forecasting and decision making, and the perception of uncertainty in flood forecasting. The workshop's concept was to have a small group of flood forecasters from different river basins working through a number of case-studies, each one representing a potential flood situation as forecasted by EFAS. On the first day, the participants worked in groups on each case-study. The second day was targeted mostly to plenary discussions on the use of EPS in flood forecasting.JRC.H.7-Land management and natural hazard

New dimensions in early flood warning across the globe using grand-ensemble weather predictions

Early and effective flood warning is essential to initiate timely measures to reduce loss of life and economic damage. The availability of several global ensemble weather prediction systems through the “THORPEX Interactive Grand Global Ensemble” (TIGGE) archive provides an opportunity to explore new dimensions in early flood forecasting and warning. TIGGE data has been used as meteorological input to the European Flood Alert System (EFAS) for a case study of a flood event in Romania in October 2007. Results illustrate that awareness for this case of flooding could have been raised as early as 8 days before the event and how the subsequent forecasts provide increasing insight into the range of possible flood conditions. This first assessment of one flood event illustrates the potential value of the TIGGE archive and the grand-ensembles approach to raise preparedness and thus to reduce the socio-economic impact of floods

Coupling Meteorological and Hydrological Models for Floodforecasting

This paper deals with the problem of analysing the coupling of meteorological meso-scale quantitative precipitation forecasts with distributed rainfall-runoff models to extend the forecasting horizon. Traditionally, semi-distributed rainfall-runoff models have been used for real time flood forecasting. More recently, increased computer capabilities allow the utilization of distributed hydrological models with mesh sizes of 1km and smaller. On the other hand , meteorological models, providing the quantitative precipitation forecast, tend to produce average values on meshes ranging from slightly less than 10 to 200 km. Therefore, to improve the quality of flood forecasts, the effects of coupling the meteorological and the hydrological models at different scales are analysed in the context of the European FP5 project EFFS.JRC.H.7-Land management and natural hazard

Forecasting Medium-range Flood Hazard on European Scale

The European Flood Alert System (EFAS) prototype has been running pre-operationally for all of Europe since 2005. EFAS is now providing 3-10 day probabilistic hydrological forecasts for 22 national hydrological services. Recently, the forecasts were also made accessible in real time to the EFAS partners via an interactive password-protected web-based information system (EFAS-IS). This article gives a short overview of EFAS and illustrates the communication tools that are used in this early warning system, and that were developed in close collaboration with the hydrological national services forming part of the EFAS network. Furthermore, some results of a long-term skill assessment are presented, which underline the positive aspects of using probabilistic forecasts for mid-range flood forecasts.JRC.A.1-Work programme E