Water shortage in the Iberian Peninsula has always been a problem. An abstract of recent research by Dr Caroline Ummenhofer and others at the US Woods Hole Oceanographic Institute, published in the journal Nature Geoscience, indicates that Iberia now has the driest climate for 1,200 years. How and why has this happened and what are the effects of drought in the Iberian Peninsula?
Rainfall patterns
Iberia gets most of its rain in winter when wet, low pressure systems blow in from the Atlantic Ocean. In summer, dry high-pressure systems migrate from Bermuda to the Azores and can block any wet weather, pushing it north towards Scotland and Scandinavia. Before 1850, those “Azores highs” occurred about once every ten years (based on simulated data). Since 1980 the frequency has increased to once every four years (based on actual data). The cause is a rise in carbon emissions resulting in global warming. They are specified as “anthropogenic” emissions as they result from human activity.
Where does Iberia get its water from and when did shortage become critical?
In Spain, the main catchment of water is the 85,000km2 basin of the River Ebro in north-east Spain. The Ebro flows from the Cantabrian mountains 910km to the Mediterranean Sea. Some of this water is transferred to the dry south along canals running close to the Mediterranean coast. Not surprisingly, the northeast objects to “their water being given away” and this prompted the building of many controversial desalination plants as an alternative in the southern Costa Blanca.
In 1970, Spain decided to turn the southwest regions of Murcia and Almeria into Europe’s market garden. The regions have no major rivers and the lowest rainfall in Spain. To augment other supplies, a 300km water pipeline was built to the region. But the increasing frequency and severity of recent heatwaves, especially this year after an unusually dry winter, has reduced the water stored in reservoirs to 40.4% of their capacity. That is 20% below the average over the last decade at this time of year. Further south, in Andalusia (Costa del Sol) reservoir water levels are particularly low at 25% capacity.
Portugal’s reliance on bottled water
In Portugal, the hydrological basins of four of their rivers, the Tagus, Douro, Guadiana and Minho, are shared with Spain. They occupy 56,930km2 in Portugal and 207,630 in Spain. Portugal, over the years, has built many dams, one forming the largest artificial lake in Europe – Alentejo. 60 of these dams are hydroelectric power stations.
Portugal has eight River Basin Management districts responsible for water supply in their local district. Most of their water supply is provided to the agriculture industry. Second priority is industry and, finally, domestic use. Hence, Portugal domestic use still relies heavily on bottled water. The River Tagus rises in the Spanish mountains east of Madrid and flows through western Spain and Lisbon to the Atlantic Ocean. Its flow rate has steadily reduced over recent years and latest predictions are that it could dry up completely unless climate change is reversed.
Effects of the drought
The main effects of Iberian drought are on the agricultural and tourism industries, both of which contribute significantly to the Spanish and Portuguese national economies. This is aggravated by the recent eruption of many forest wildfires caused by the intense heatwaves. Since May, the hottest month on record ever, some 260,000 hectares in Spain and 48,000 in Portugal have been charred by wildfires and these figures increase daily.
Spain’s irrigated agricultural land has increased from 900,000 hectares to 3.4M hectares over recent decades. Lately, it has expanded to supply Europe with newly fashionable products, such as avocados – a natural product of Mexico. Málaga Province became Europe’s largest supplier of avocados but they have now had to destroy 1,500 of 6,000 trees due to the shortage of water. Olive production is also threatened.
Spain is now the second most visited country in the world, with significant amounts of water used for tourist facilities, such as swimming pools and golf courses. Spain is now nearing the physical limits of its water management system and is undertaking a drastic review of a strategic plan on how to use its water in the future.
Meanwhile, water restrictions have been introduced in different autonomous regions. Catalonia has limited domestic water consumption to 200 litres per person per day. In many regions beach showers and footbaths have been closed, filling of swimming pools and garden watering, car and street washing banned. In some areas mains water is being cut off overnight.
Portugal’s avocado farming
Portugal has restricted the use of hydroelectric power plants to two hours per week to guarantee the drinking water supply to its 10M inhabitants for 2 years. In southern Portugal, (Silves, Lagoa and Portimão) 1,800 farms have been told to halve the irrigation of some crops. For example, in recent years avocado farming has also boomed in southern Portugal. But an avocado tree uses as much water per day as a family of four. Farmers have drilled many bore holes to supply the water from aquifers.
That is a further depletion of ground water reserves in an area that is vulnerable to desertification. In the Algarve, the State Environmental Agency in Faro controls local water supply but many avocado plantations have no water meters and use cheap immigration labour. Despite fines, control is difficult to implement. Maybe man can live without avocados, but not without water.
