Copernicus Emergency Management Service (CEMS)
European Flood Awareness System (EFAS)
2023 Report
By Elizabeth Kiflay (RWS)
1. 2023 CEMS EFAS Flood Notifications
In 2023, a comprehensive total of 2,336 notifications were issued by the Copernicus Emergency Management Service Flood Forecast Analytics and Dissemination Center, encompassing 251 formal notifications, 274 informal notifications, and the predominant category of 1,811 flash flood notifications. Analysis of the notification distribution over the year uncovered noteworthy variations. In total, January stood out as the month with the highest number, reaching a peak of 309 total notifications. In contrast, July recorded the lowest frequency with only 16 total notifications. Nevertheless, the formal notifications were more prevalent in August, (52 notifications), closely followed by January (42 notifications). This analysis emphasizes the annual variability of the flood occurrence and their notification issuing system, showcasing fluctuations in response to different months and a diverse array of notification types, as depicted in Figure 1.
1.1 Comparison with Previous Years’ Flood Notifications
The variability in EFAS flood notifications across different years can be primarily attributed to two key factors: the prevailing climate conditions in a given year and updates to the EFAS protocol, including forecast model set-up and criteria for the issue of notifications. Figure 2 depicts EFAS flood notifications from 2013 to 2023. Noteworthy is the standout performance of the year 2023, which recorded the highest number of flood notifications, closely followed by 2020. The substantial increase in notifications during 2023 can be predominantly linked to both intra-annual climatic pattern and modifications in the EFAS flood forecasting model. EFAS v5.0 was operationally released on September 20th 2023 (https://www.efas.eu/en/news/efas-version-50-operational-release-20-september-2023). One of the key features of EFAS v5.0 is the increased spatial resolution (from 5 Km to 1 arcmin, approximately 1.4 km), resulting in a reduction of the catchment area which reporting points can be generated (from 500 km2 to 150 km2). However, the informal notifications were issued for 1000 km2 and formal 2000 km2 (https://www.efas.eu/en/efas-notifications?field_month_value=&field_year_value=).
Figure 2: Total number of EFAS notifications (Formal, Informal and Flash Flood) issued per year from 2013 to 2023.
1.2 Seasonal Variation
Figure 3 presents the seasonal fluctuation of EFAS flood notifications over the past five years, classified seasons; winter (December, January and February), spring (March, April and May), summer (June, July and August), and Autumn (September, October and November). A consistent pattern emerges, highlighting the winter season as the period with the highest flood notifications, while the lowest occurrences are observed during summer. However, when excluding the flash flood notifications, winter and autumn show similar numbers of notifications.
Figure 3: Seasonal variation of EFAS notifications from 2019 to 2023 (Formal, Informal and Flash Flood).
1.3 Number of Notifications isssued per Country
In 2023, the distribution of EFAS flood notifications exhibited distinctive trends among the different countries covered by the EFAS system. Romania emerged as the country receiving the highest number of notifications, constituting 8% of the total notifications. In close succession, Spain and Italy reported the second and third-highest numbers, representing 7.6% and 7.2% of the total notifications, respectively. This variability in notification numbers is intricately linked to the size of the catchment area in each country, coupled with the regional climate. Larger catchment areas, combined with specific climatic conditions, contribute to the observed differences in the number of flood notifications.
Figure 4: Number of EFAS notifications issued per country.
2. Global Reporting Tool (GRT)
The Global Reporting Tool (GRT) documented a total of 1,163 flooding incidents in 2023. Notably, Europe emerged as the region with the highest percentage of flood reports, closely followed by Asia. Africa and South America shared the third position, each contributing an equal number of flood reports, as illustrated in Figure 5.
Figure 5: Global Flood reports in 2023.
Figure 6: Number of flood reports in 2022 and 2023.
The total global flood reports in 2023 exhibited a significant increase in comparison to 2022, as presented in Figure 6. This surge was evident across all continents, except for Oceania. Particularly striking were the substantial increases in Europe, recording a remarkable 71.4% rise, and Africa, demonstrating a significant 36% increase. These findings suggest that the year 2023 was characterized by climatic conditions conducive to flooding, emphasizing the global impact of climate patterns on the frequency of flood incidents. However, analyses over more years are needed to assess potential trends across the continents.
3. Notable Flood Incidents Across Europe in 2023
In 2023, Europe witnessed several significant flooding incidents, impacting various regions:
Germany: Prolonged heavy rainfall in December triggered flooding across multiple German states.
Italy: Tuscany grappled with catastrophic flooding in November, while Emilia-Romagna endured devastating floods in May.
Storm Babet, Ireland & UK: Ireland faced severe flooding, Scotland issued evacuation warnings, and England experienced widespread flooding in October.
Slovenia: In August, a catastrophic weather event led to severe flooding and landslides.
Aragón Region, Spain: Torrential rain on July 6 resulted in flash floods in Alcañiz and Zaragoza.
Serbia, Kosovo, and Romania: Serbia faced severe flooding, Kosovo experienced flooding, and Romania saw destructive flooding in June.
Latvia: In April, rain and snow melting caused flooding in Latvia's Daugava river valley.
Southern Türkiye: Catastrophic flooding hit Şanlıurfa and Adıyaman Provinces in March.
Greece, Bulgaria, and Turkey: Storm Daniel caused widespread flooding in these countries in September.
Balkans: Floods were observed in the Balkans in January.
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