Fournoi study gauges water scarcity and its causes
Overtourism will only make the problem much worse, say experts, after research points to severe drought on Aegean islands
In 2023, more than 32 million tourists visited Greece, a number that was 17.6% higher compared to 2022. Overtourism is already a reality on many Greek islands, and appears to be largely responsible for making existing water scarcity more severe. Based on a pilot study carried out in Fournoi, a complex of small islands in the eastern Aegean, it appears that they already need more than double the amount of water that they can produce naturally. In fact, demand is expected to double by 2030, a fact that, as scientists who participated in the research told Kathimerini, is attributed directly to the further increase in the number of tourists. The pilot program is expected to soon expand to 10 more islands to determine their water levels and seek solutions.
Dimitris Emmanouloudis, UNESCO chair on conservation and ecotourism of riparian and deltaic ecosystems, and director of the laboratory for the analysis and management of natural disasters and technological risks at the Democritus University of Thrace, explains that the Fournoi islands were chosen after discussions with General Secretary of the Aegean and Island Policy Manolis Koutoulakis on the issue of water scarcity on the islands. “We wanted to find an island as an experiment so we could study it thoroughly and see what conclusions emerge. So, they looked for an island that is not extremely small and is located approximately in the middle of the Aegean,” he says.
The study started in March 2022 and ended in December 2023, while the participating agencies were the Department of Natural Environment and Climate Resilience at Democritus, and the section of UNESCO that manages ecotourism and natural and coastal ecosystems at a global level. They also collaborated with the Laboratory of Climatology and Atmospheric Environment at the University of Athens.
Today, Fournoi has just over 1,300 permanent residents and, according to Emmanouloudis, received 8,000 tourists in 2023. In order to meet the island’s demand for water, “we need about 90,000 cubic meters of water per year, while the island has the capacity to produce 30-40,000 cubic meters. The remaining amount is supplied through desalination. Based on the models we processed, we saw that in 2030 Fourni will need 200,000 cubic meters of water per year, because the number of tourists by then is expected to have reached 25,000.”
For his part, Pantelis Xofis, associate professor in the Department of Forestry and Natural Environment at the International Hellenic University, explains that these needs constitute the water footprint, which is “an indicator of water consumption and concerns both direct and indirect consumption for the production of various products we use.”
Xofis says that once we know the water footprint, “we can avoid activities with a large water footprint and ensure water sufficiency not only for current generations, but also for future ones.”
It is worth noting that, according to Emmanouloudis, the water footprint of each resident and potential tourist was calculated, among other things, through the use of questionnaires that were handed out on the islands to obtain the weighted averages.
‘Desalination can address the issue of water supply but it is a particularly costly, energy-intensive method and it burdens the environment’
The research on Fournoi also concerned seeing how much dry heat changed on the island from 1980 to 2020, “a period for which we have satellite data of high spatial and spectral resolution and reliable meteorological data,” says Xofis. The study eventually found that there was an average increase in temperature on Fournoi which ranges around 1.2 degrees Celsius. “It may sound like a small number, but it’s a pretty big increase,” he notes.
On the other hand, rainfall in the archipelago does not show a corresponding downward trend, but has remained rather stable over the last 40 years. According to Xofis, the Fournoi islands have the peculiarity of having a long period of dry heat, which starts in April and ends in October. During this time there is no rainfall. Despite that, the island has a relatively high amount of rain, exceeding 600 mm, which, however, falls over a very limited period of time, mainly in severe weather events. “Therefore, what changes is not the amount of precipitation, but its distribution,” he adds.
Moreover, according to Emmanouloudis, despite the high annual rainfall, the islands do not retain this water because of the limestone rock that makes up most of the islands.
The study also looked into the temperature of the soil’s surface, which, according to Xofis, “was calculated through some thermal channels of the NASA Landsat satellite.” As it turned out, from 1984 to 2022, “there was a huge increase in the dry heat of the soil’s surface, which reduced the water stored in the soil and is used during dry periods.” It is indicative that in the 1980s the Temperature Condition Index (TCI) stood at 0.8, “which means that there was practically no drought. Now, it has reached about 0.2, which means severe drought,” Xofis says.
Regarding how this is reflected in the vegetation on the islands, he says that “there we had a positive surprise. The vegetation seems not to be in a state of intense stress.” This is something that, according to Xofis, is explained by the fact that on the island there is maquis vegetation and shrubland, which are resistant to drought. At the same time, on Fournoi, as on most islands in the Aegean, there has been a decrease in animal husbandry, which has allowed vegetation to reoccupy areas which had been left bare by sheep and goats.
However, according to Emmanouloudis, the lack of water on the islands “will certainly concern us more in the future.” And this not only depends on the climate models and whether we will have a drought or a lack of rainfall, “but on the dramatic increase in tourists that Greece receives annually, which is already about three times its population. This does not happen in any other European country. Most of these tourists are concentrated in the Aegean, so the problem will definitely intensify in the future.”
He said that, on most islands, mayors try to deal with the issue mainly through desalination. “However, desalination is not a panacea. It can address the issue of water supply but it is a particularly costly, energy-intensive method and it burdens the environment through waste byproducts which are thrown into the sea.”
Through the pilot program, scientists propose the construction of small-scale technical projects combined with ecosystem-based adaptation techniques, Emmanouloudis says. “This combination is part of the large family of nature-based solutions.” These works include checking dams to collect water – even the smallest amount – through the streambeds during the winter and rain basins with accompanying underground water tanks to reduce losses from evaporation. These solutions “can increase the annual production in Fournoi to 90,000 cubic meters of water per year,” he adds.
The next step is to sign an agreement between UNESCO, the Democritus University of Thrace and the General Secretariat of the Aegean and Island Policy for the research to be extended to an additional 10 islands, which will be geographically scattered “to have a much better picture,” Emmanouloudis says.
Xofis says the goal is to create a model that will be applied on all the islands. “Besides, most islands may face water shortages, as they have no natural water reservoirs, nor is it easy to transport water from a remote area. At the same time, they receive an abnormally large number of tourists and in several cases have developed beyond their capacity and what their natural resources can withstand,” he explains.
“And this has happened to islands like those in the Cyclades, which are among the driest regions of Greece.”
