Vulnerabilities - Spain

Annual and seasonal drought patterns across the Iberian Peninsula were analyzed for the period 1906-2010. The results showed a clear drying trend for most of the Iberian Peninsula with maximum rates of change in the south, south-eastern and central Iberia as well as in the Ebro basin at the annual scale and also for spring, but with largest drying trends for summer (26).

The increase in drought severity experienced in the Iberian Peninsula for the last decades was caused by greater atmospheric evaporative demand derived from temperature increase (26,27). No significant trend in precipitation was found (26). In another study, covering the period 1971 - 2015, a clear drying trend was identified in most of the Iberian Peninsula, and this trend was related to the decreased precipitation and the increased reference evapotranspiration (28). An analysis of changes in aridity in the Iberian Peninsula from 1960 to 2017 showed trends with significant tendencies at only 16 out of 45 stations across the peninsula; all of these significant trends were negative, indicating a tendency towards an increase in aridity over the series analysed (30).

Also, for Galicia, in the Northwest of Spain, an increase in the number of drought periods and the intensity of drought events was observed over the period from 1960 to 2020 as a result of decreased precipitation (29). The most serious drought in the Iberian Peninsula in 60 years occurred in 2005, reducing overall EU cereal yields by an estimated 10 % (8).

Most studies on water supply and demand conclude that annual water availability would generally increase in northern and northwestern Europe and decrease in southern and southeastern Europe (17). In the agricultural sector, irrigation water requirements would increase mainly in southern and southeastern Europe (18). The overall balance between demand and supply under climate change suggests that water stress may occur in the Iberian peninsula (due to less supply), northwestern Europe (due to increasing demand) and eastern Europe (due to changes in demand and supply) (19).

Aquifers usually recharge slowly, and current abstraction levels may not be sustainable under future climate change scenarios. In some areas of southern Europe aquifers are already overexploited. When aquifers near the coast are overexploited, salt water may intrude, thus reducing water quality in the aquifer (19).

Groundwater extraction for irrigation across Spain tends to be developed and financed by private farmers and small and medium sized firms. The absence of an integrated approach may lead to problems of over-exploitation of groundwater resources in an area where the ratio of water withdrawals to water availability is projected to increase by the 2070s (15).

Climate change modeling (20), using a range of climate scenarios, has predicted that droughts are likely to increase in frequency and intensity across most of Western Europe. Notwithstanding the severe impact of major droughts on the fabric of society, the institutional frameworks to cope with droughts at European level are poorly developed (21).

Changes in dry and wet spell characteristics in Europe have been projected for 2021–2050 compared with 1961–1990, based on Regional Climate Model simulations under the A1B emission scenario. From the results it can be concluded that significant changes in dry and wet event characteristics are expected with high confidence in the southernmost (mainly France, Italy, and Spain) and northernmost (mainly Iceland and Scandinavia) regions of Europe, respectively. Southern Europe is most probably facing an increased risk of longer, more frequent, severe, and widespread droughts, while northern Europe is facing increased risk of intensified wet events. For precipitation, the most pronounced changes are found for the Iberian Peninsula in summer (−17.2%) and for Scandinavia in winter (+14.6%) (25).

Agriculture

In Spain, impacts are being notable on agriculture. Some irrigated areas have been reconverted due to water scarcity. Agriculture is now experiencing limited developments: extraction costs are increasing, agricultural margins are reducing and a greater uncertainty is being put on production, leading to loss of competition. In Spain, the reduction in farm incomes following the 1990-1995 droughts was estimated to 1800 Mio €. In 2005, agricultural inputs decreased by 12%. Vegetal production decreased by 13% while stockbreeding decreased by 2.6%. In vegetal production, cereals and wine respectively decreased by 42% and 20%. Non-irrigated crops and pastures suffered important losses reaching 2,500 Mio € (22).

Hydropower

Several Member States have reported reduction in hydroelectricity production due to drought events (Finland, France, Portugal, Spain). As hydroelectricity production is related to the amount of water stored in the upper reservoirs, the production level can be lower during a drought. Peak demands then need to be satisfied by other means available in a short term (gas turbine, etc). The amount of losses depends on hydroelectricity infrastructures and drought severity: 50 Mio € in Finland in 2002-2003, 210 Mio € in Spain in 1990-1995, 182 Mio € in Portugal in 2004-2006 (22).

In Spain, the 2005 drought led to a reduction of 36% in national hydroelectric power production, with respect to the past five year average. The decrease in hydraulic and nuclear production has been compensated by an increase in fuel-gas plant production and combined cycles that increased their production by respectively 28% and 66%, compared to 2004. This extra production led to an additional cost of 713 Mio € (22).

The definition of drought

Drought is a natural phenomenon defined as sustained and extensive occurrence of below average water availability. Drought should not be confused with aridity, which is a long-term average feature of a dry climate. It is also distinct from water scarcity, which constitutes an imbalance between water availability and demand (1).

Three general types of drought may be recognized (7):

• meteorological droughts – defined on the basis of rainfall deficiency;
• hydrological droughts – where accumulated shortfalls in river flows or groundwater replenishment are of primary importance;
• agricultural droughts where the availability of soil water through the growing season is the critical factor.

During lengthy droughts, all three categories may combine to increase water stress. High temperatures are not a necessary component of drought conditions, dry winters can lead to water resources stress in the following summer.

Droughts might manifest themselves either as short but extreme single season droughts (such as the hot summer of 2003) or longer-term, multi-season droughts, and they might be local or widespread in nature (7).

Vulnerabilities in Europe

The European Commission has estimated that at least 11 % of Europe's population and 17 % of its territory have been affected by water scarcity to date and put the cost of droughts in Europe over the past thirty years at EUR 100 billion (1).The drought of 2003 caused a total economic cost of over €13 billion in around twenty European countries (2,7).

Vulnerabilities – European trends in the past

In 2012 the IPCC concluded that there is medium confidence that since the 1950s in particular southern Europe has experienced a trend toward more intense and longer droughts (24). There is no evidence that river flow droughts have become more severe or frequent over Europe in general in recent decades (3), nor is there conclusive proof of a general increase in summer dryness in Europe over the past 50 years due to reduced summer moisture availability (4). Strong increases in the area of combined severe dry and wet conditions in Europe over the last three decades have also been identified, though, and it has been suggested that without global warming droughts would have been smaller and less pervasive (13).

Regional differences

Despite the absence of a general trend in Europe, there have been distinct regional differences. In particular, more severe river flow droughts have been observed in Spain, the eastern part of eastern Europe and large parts of the United Kingdom (3). However, in the United Kingdom there is no evidence of a significant increase in the frequency of occurrence of low river flows (5).

Increasing drought deficits were observed in Spain, eastern Europe and large parts of central Europe with changes in precipitation cited as a major explanatory factor (11). Others (12) have indicated that the proportion of Europe experiencing extreme and/or moderate drought conditions has changed significantly during the twentieth century with fewer droughts over Scandinavia, Netherlands and the Ukraine and more in areas of eastern Europe and western Russia.

In 2012 the IPCC concluded that there is medium confidence that since the 1950s in particular southern Europe has experienced a trend toward more intense and longer droughts (24).

Water extraction

Water extraction as well as water management across catchments and changes in land use and management also make it very difficult to attribute changes in average water discharge, floods and droughts to climate-change forcing (8).

Changes in drought severity for western Europe have been attributed to a changing climate but for eastern European countries the increased extraction of water for economic expansion is also a significant factor (15). It has been suggested that the influence of increases in water consumption on future droughts may even be of the same magnitude as the projected impact of climate change (16).

Vulnerabilities – Future projections for Europe

In 2012 the IPCC concluded that there is medium confidence in a projected increase in duration and intensity of droughts in some regions of the world, including southern Europe and the Mediterranean region, and central Europe (24).

River flow droughts are projected to increase in frequency and severity in southern and south‑eastern Europe, the United Kingdom, France, Benelux, and western parts of Germany over the coming decades. In snow-dominated regions, where droughts typically occur in winter, river flow droughts are projected to become less severe because a lower fraction of precipitation will fall as snow in warmer winters. In most of Europe, the projected decrease in summer precipitation, accompanied by rising temperatures which enhances evaporative demand, may lead to more frequent and intense summer droughts (9).

As a result of both climate change and increasing water withdrawals, more river basins will be affected by severe water stress, resulting in increased competition for water resources. The regions most prone to an increase in drought risk are the Mediterranean and south-eastern parts of Europe, which already suffer most from water stress (10).

According to research based on six regional climate models, there is not a simple north–south pattern of decreased–increased drought, with models projecting fewer events for parts of the Iberian Peninsula and parts of the Mediterranean. Considerable uncertainty exists at the regional scale. For example, for Britain and northern Spain, different models project both increases and decreases. … All models project longer and more severe droughts in the Mediterranean and shorter, less severe, events for Scandinavia with greater uncertainty as to the direction of change for the rest of Europe (14).

The use of six regional climate models has demonstrated the range of uncertainty in future projections of even mean precipitation across Europe, but also enables some generalizations to be made. Increases in precipitation are likely during winter and these are likely to be largest and most persistent for northern Europe. In contrast, large decreases in precipitation are likely during summer, these being largest in southern Europe (14).

For longer-duration droughts there is a clearer spatial pattern, which indicates fewer droughts in northern Europe due to larger increases in winter precipitation and more droughts of increasing severity in the south (14).

Biodiversity

Droughts may strongly affect biodiversity all across Europe. Some examples (8):

• The environmental impacts of droughts can be exacerbated by unsustainable trends in water use. The worst combination appears when drought strikes freshwater ecosystems already weakened by excessive water withdrawals. For example, Lake Iliki, some 100 km northeast of Athens, has been reduced to a third of its original size, partly by a severe drought in 2000 but also as a result of increasing drinking water demand. Likewise, Lake Djoran, located between Greece and the Former Yugoslav Republic of Macedonia, is at risk of drying up, thus threatening one of the richest inland fishing stocks in Europe.
• Wetlands are particularly vulnerable to drought. The drought that affected Spain in the first half of the 1990s reduced by 97 % the flooded area of the Natural Park of the ‘Tablas de Daimiel’, the most important wetland area in the interior of the Iberian peninsula. Here too, water withdrawals, in this case for agricultural purposes, contributed to the loss.
• Droughts can cause the deterioration of water quality in rivers, lakes and reservoirs by exacerbating algal blooms that reduce the oxygen available for aquatic species. In the summer of 1999, for instance, these processes affected many lakes in Finland.
• Droughts may also weaken the resistance of certain plant species to plagues and increase their susceptibility to forest fires, as happened in the Greek island of Samos in the summer of 2000.
• Finally, drought can threaten the very survival of species in certain areas. The prolonged drought that affected southern Spain in the mid 1990s caused a high mortality rate among maritime pines and severely withered green oak and cork oak forests.

Soil erosion

Droughts may also trigger soil erosion, mainly in Mediterranean areas. One way this happens is through a reduction in vegetation cover caused by forest fires or by increased plant mortality due to water stress. In addition, when the soil is very dry, the water infiltration rate decreases. Consequently, if a period of drought is followed by heavy storms, erosion is triggered by surface runoff. The problem is especially acute in the arid and semi-arid Mediterranean areas where the process may lead to desertification (8).

Vulnerabilities – Future projections for Spain

Galicia

Drought conditions over Galicia in the northwest of Spain are projected to increase over the twenty-first century for both a moderate (RCP 4.5) and high-end (RCP 8.5) scenario of climate change. According to these projections for the second half of this century (2061–2096), drought events will occur more often, be more intense, but will be shorter (31).

Adaptation strategies

Pan-European

Europe should view 2003 as a wake-up call. The 2003 drought should be the catalyst for actions aimed at reducing drought impacts across all relevant sectors (7). Drought is not mentioned in European energy policies. Similarly European transport navigation policy makes no reference to low flow conditions, whereas health policies make few provisions for reduced water supplies and deteriorating water quality. Drought is one criterion for exemption to the requirements of the Water Framework Directive – an increasingly likely situation. It makes no provision for managing biodiversity protection during severe droughts (7).

In contrast to internal policy, drought is addressed as a real issue in EU development policies. Drought is seen as a threat to sustainable development, a humanitarian issue and a driver of mass migration and political instability (7).

EU policy orientations for future action

According to the EU, policy orientations for the way forward are (23):

• Putting the right price tag on water;
• Allocating water and water-related funding more efficiently: Improving land-use planning, and Financing water efficiency;
• Improving drought risk management: Developing drought risk management plans, Developing an observatory and an early warning system on droughts, and Further optimising the use of the EU Solidarity Fund and European Mechanism for Civil Protection;
• Considering additional water supply infrastructures;
• Fostering water efficient technologies and practices;
• Fostering the emergence of a water-saving culture in Europe;
• Improve knowledge and data collection: A water scarcity and drought information system throughout Europe, and Research and technological development opportunities.

National

Adaptation activities currently seem to be focused on flood management and defence, while adaptation measures related to the management of water scarcity and drought, although recognized as equally damaging, do not yet seem to be widespread (2).

Spain

The integrated management plans for water resources in Spain constitute one component for adaptation to climate change. The National Water Plan accounts for potential climate change induced reduction in water availability and analyses the effect of these reductions on management and planning (19).

Drought Management Plans (DMPs) were launched in Spain in 2007 for all the river basins. The main objectives of these Plans are to anticipate droughts, foresee solutions to satisfy priority demands and reduce socio-economic and environmental impacts. The bases for the DMPs are (22):

• Indicators for a quick drought status early enough to act according to the forecasts of the Plan
• Knowledge of the resources system and its elements’ capability to be strained during scarcity situations
• Knowledge of the demand system and its vulnerability towards droughts
• Structural and non-structural alternatives to reduce drought impacts, and adaptation according to the status indicator
• Measure the cost of implementing measures
• Adapt the administrative structure for its follow-up and coordination among the different Administrations involved (Ministry, regional governments, municipalities)
• Discuss Plans, results and follow-ups with all interested parties, ensuring full public participation to avoid social conflicts.

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Spain.

1. EC (2007a), in: EEA (2009)
2. Anderson (ed.) (2007)
3. Hisdal et al. (2001), in:EEA, JRC and WHO (2008)
4. Van der Schrier et al.(2006), in:EEA, JRC and WHO (2008)
5. Hanneford and Marsh (2006), in:EEA, JRC and WHO (2008)
6. Van Lanen et al. (2007), in: EEA (2009)
7. Eisenreich (2005)
8. EEA, JRC and WHO (2008)
9. Douville et al. (2002); Lehner et al. (2006); Feyen and Dankers (2008), in:EEA, JRC and WHO (2008)
10. Alcamo et al. (2003); Schröter et al. (2005), in: EEA, JRC and WHO (2008)
11. Demuth and Stahl, 2001, in: Blenkinsop and Fowler (2007)
12. Lloyd-Hughes and Saunders (2002), in: Blenkinsop and Fowler (2007)
13. Dai et al. (2004), in: Blenkinsop and Fowler (2007)
14. Blenkinsop and Fowler (2007)
15. Lehner et al. (2006), in: Blenkinsop and Fowler (2007)
16. Lehner and Döll (2001), in: Blenkinsop and Fowler (2007)
17. Arnell (2004), in: European Environment Agency (EEA) (2005)
18. Döll (2002), in: European Environment Agency (EEA) (2005)
19. European Environment Agency (EEA) (2005)
20. Arnell (1999), in: Eisenreich (2005)
21. Vogt and Somma (2000), in: Eisenreich (2005)
22. European Commission (DG Environment) (2007)
23. Commission of the European Communities (2007)
24. IPCC (2012)
25. Heinrich and Gobiet (2012)
26. Coll et al. (2017)
27. Vicente-Serrano et al. (2014a), in: Coll et al. (2017)
28. Páscoa et al. (2021) 
29. Lorenzo et al. (2022)
30. Paniagua et al. (2019)
31. Alvarez et al. (2024)