The European Drought Risk Atlas is a qualitative and quantitative analysis of drought risk in European countries for current and future climate conditions. Just published as part of the EDORA initiative, the atlas provides a picture of drought risk and impacts in five different socio-economic sectors and systems: agriculture, water supply, energy, river transport, ecosystems
What are the present and the future for droughts? The scientific literature agrees that, due to the climate crisis, this phenomenon is becoming increasingly severe in different areas of the world, including the Mediterranean basin. However, to understand how to deal with droughts – that is, to take appropriate adaptation measures – impacts must be properly analysed and quantified.
This is the core of the new European Drought Risk Atlas, developed by a consortium of European and international universities and research centres coordinated by CIMA Research Foundation under the supervision of the European Commission’s Joint Research Centre (JRC), as part of the EDORA (European Drought Observatory for Resilience and Adaptation) initiative. Through the analysis of impact chains and the quantitative assessment in the current and future climate, the atlas returns a picture of drought impacts in a number of key sectors, from agriculture to energy, from river transportation to ecosystems, providing a risk assessment and serving as a supporting tool to guide drought management.
A multi-sectoral analysis
Presented to the European Parliament on Oct. 27, the European Drought Risk Atlas represents one of the most important outputs of the initiative. Managing droughts is complex, mainly because impacts that affect very different socio-economic sectors and systems may occur at different time scales and have cascading consequences. For example, agriculture is one of the most affected sectors; yet, depending on the type of crop, impacts can be more or less intense, and be followed by indirect effects such as price increases and employment losses.
“With the new atlas we have tried to identify the drivers and to quantify the losses relative to the five socio-economic sectors and systems: agriculture, water supply, energy, river transportation, and terrestrial and freshwater ecosystems,” explains Lauro Rossi, Program Director of CIMA Research Foundation and first author of the atlas. “Studying the impacts of drought in different sectors provides elements for setting up a multi-sectoral perspective for the development of adaptation pathways. Such a perspective is necessary if we don’t want that, in an attempt to reduce impacts in an area, we harm another one.”
Impact chains and machine learning to assess drought risk
The EDORA risk assessment approach is based on two complementary methods: conceptual and data-driven models. The first method consists of an analysis of impact chains, that offer a visual representation of how drivers interact to produce a certain drought risk. While not producing a quantitative assessment of risk, impact chains provide not only a useful guide for the data-driven assessment, but also entry points for managing drought risks.
The second method is a quantitative impact analysis of drought, carried out through machine learning techniques. Based on historical timeseries, an algorithm learns the relationship certain adverse climate conditions impacts on exposed elements (grouped in vulnerability clusters). For instance, the algorithm can learn that certain climate conditions determine agricultural losses in an area for a given crop. After validating the algorithm for current climate conditions, researchers also conducted the same analysis for different future climate scenario corresponding to temperatures increase by 1.5°C, 2°C and 3°C compared to the pre-industrial period, thus also providing information on how drought risk might change in the European Union at different levels of warming.
“It should be noted that these projections do not consider possible variations of exposed elements, land use, infrastructures, physical-chemical effects (e.g. CO2 fertilization), mitigation and adaptation measures that will have to be implemented,” Rossi says. “Still, this approach allows us to isolate the contribution of climate change, that is, to assess how climate by itself influences drought risk.”
Drought, the European picture
This analysis gives the first transregional and systemic picture of drought in Europe, now and in a warmer future. What does this picture show? Unfortunately, but not unexpectedly, losses can be significative. For example, losses in the agricultural sector affect the whole Europe – not only the Mediterranean area – even reaching an average annual loss up to 10% in certain areas. These losses could even double in a world +2 or +3 warmer.
More complex is the issue of water supply. The atlas data highlight that smaller amount of water available can increase the concentration of pollutants, necessitating additional treatment and monitoring to ensure their quality; this, in turn, implies the need for additional facilities increasing overall costs. Historical datasets reveal that the abstractions at the beginning of the drought may increase significantly compared to average. While for some regions, such as Scandinavia, water resources may be sufficient to meet demand, countries such as Spain (which already current abstractions are significant), may not afford extra-extraction. This scenario becomes significantly worse in future projections, especially in the Mediterranean.
Moreover, the report provides also a picture of risk for the energy sector, river transport sector, and ecosystem sector in which losses, although with significant geographic differences (for example, river transport is concentrated in only a few countries), point to one thing: adaptation and mitigation actions are urgent because impacts are already significant and, if temperatures rise further, can become dramatic.
Adaptation: the need for a holistic and cooperative approach
“The intent of the atlas is not to promote specific drought measures, but rather provide scientific evidence and data to inform current and future decision” says Rossi. “We want to quantify the wide-ranging impacts of drought, which affect diverse systems at different time scales. Furthermore, these complex impacts often interact, resulting in cascading effects. Consequently, it is crucial to have a holistic approach in addressing drought risk. In addition, it will be necessary to strengthening collaborations at the European level, because responding to a phenomenon with such extensive effects also means acting collectively at continental level, both in terms of adaptation strategies and data collection and systematization, which for some sectors is still scarce and fragmented.”
Regarding this last point, EDORA has already begun to contribute by creating the European Drought Impact Data (EDID), a collection of observed drought impact information for different socio-economic sectors (those analysed in the atlas). The database consists of a precise set of attributes describing impact in different sectors with relevant spatial and temporal references. The database integrates some regional efforts and presents additional information of events in the last decade. Compared to the regional databases, several new attributes (such as the severity level of the event) were added of the database.” At the moment, the database is still available only as a test version, but in the coming months it will be fully included within the Copernicus service system,” Rossi concludes.