Crete threatened by desertification
50% of land in Crete and 35% of land in Greece is at high risk of desertification, with dire consequences for the country’s economy and demographic.
This is the conclusion reached by a three-day scientific conference organized by the Agricultural University of Athens in Heraklion, Crete. The conference was part of the “Desire” scientific programme, comprising 28 research institutes and universities from around the world.
The findings were judged worrying by those attending the conference, as they emerge from scientific studies of the phenomenon of desertification observed in many areas of the planet. In fact Crete, due to its high risk of desertification, is a pilot study area for Greece. According to the President of the National Committee for Combatting Desertification, Professor of Soil Science Kostas Kosmas, east Crete is considered the area of Greece most at risk of desertification. There are two reasons for this: the warm climate with low rainfall, and human intervention. Today 35% of Greece is at risk of or partially subject to desertification, while 49% is at moderate risk of desertification.
– On the way to the south of Crete. Desertification is obvious on these hills –
What is desertification?
Desertification means land degradation in arid areas resulting from various factors such as climate change and human activity. Desertification lowers productivity and crop yields, forcing farmers to leave their land and move elsewhere.
Desertification and Agriculture
Farmers may be the first to suffer from desertification, but they are also part of the problem. They contribute to desertification through over-intensive use of land, over-pumping of groundwater, irrigation with water with a high mineral salt content, use of acidic chemical fertilisers and destruction of vegetation.
Desertification and Animal Husbandry
Overgrazing by thousands of sheep and goats is another contributory factor to the desertification of mountainous areas of Crete. It has been known for years that there are far more sheep and goats in Crete that the island can support. It is estimated that 1,500,000 sheep and goats graze on 55% of Cretan land, eliminating all edible vegetation in their desperate struggle to find food.
In Crete the mountainous regions with the worst overgrazing problem are the Asterousia Mountains, Mt Psiloritis and the Sfakia area. In these areas many plant types are endangered, while the fires set by the shepherds themselves to burn off dry grasses and encourage the growth of fresh grass for their herds intensifies the problems of desertification and soil erosion.
Desertification and Forest Loss
The sheep and goats of Crete also threaten the island’s forests, as young tree shoots are devoured by hungry animals, preventing renewal. The problem of forest renewal and regeneration is an important one, especially considering that forests cover just 4,5% of Crete, a figure falling to a mere 2% in Heraklion Prefecture.
Forests in Crete are threatened not only by overgrazing but also by forest fires, whether deliberate or accidental. We must not forget that forests are the most important element of balance in nature, a vital economic and health factor, and generally a valuable and irreplaceable supporter of life and civilisation.
Deforested areas are at immediate risk of erosion and desertification, as they are mountainous regions with steep slopes, and heavy rainfall easily washes away the soil when there are no tree roots to retain it.
Desertification and Urbanization – Tourist Development
Urbanization and intensive tourist development also require large amounts of water to cover the needs of local residents and visitors, a problem evident in the city of Heraklion and the tourist resorts of Heraklion Prefecture, where water needs increase exponentially every summer.
Increased water requirements in urban and tourist areas are currently met through boring new wells. In periods of low rainfall, however, these result in a fall in the water table, salination of coastal areas and drying-out of wetlands, threatening local ecosystems with destruction.
In recent years, local authorities and services have set all their hopes of a solution to the problem of drought in Heraklion and tourist resorts from Malia to Kokkini Hani on the much-discussed and costly dam of the Aposelemis River. Other solutions, such as the exploitation of the Almyros River, have never left the drawing board. However, the Aposelemis dam will take years to build and become operational, while water requirements are increasing and groundwater is falling daily. Measures are needed now if local residents and tourists in Heraklion, Malia, Hersonissos and Gouves are not to go thirsty.
Particularly as far as the city of Heraklion is concerned, many people are demanding better water management and use of treated wastewater. The Heraklion water network is old and leaky, with up to 50% of water being lost according to residents. This means that thousands of tons of water are lost due to leaks each day. To this we must add the 25,000 tons of water flushed into the sea daily from the Heraklion wastewater treatment plant, due to the lack of tertiary treatment to make the wastewater suitable for irrigation.
Desertification in the Messara Plain
South of Heraklion, in the Messara area which is at immediate risk of desertification, over 15 million euros have already been spent on the construction of the Faneromeni dam near Vori. Work began in 1999 and was completed in 2003, with a budget of 16.7 million euros. The dam is an earth dam with a capacity of 17 million cubic metres. This water would be a valuable resource for the thirsty Messara plain – if it ever got that far. But we must wait a few more years, as this April, four years after the completion of the dam, the construction of the irrigation pipelines has only just been put to tender.
Another major irrigation project is planned for the Messara plain and the south-east of Rethymnon Prefecture, with an expected completion date of 2015. This is the redirection of the Platys River, which flows into the sea at Agia Galini. It is estimated that almost 120 million cubic metres of surface and groundwater flow in the Platys catchment basin. Just 3% of this water is used today, and about 50 million cubic metres of water end up in the sea each year.
The project aims to create a reservoir of 20 million cubic metres of water and transfer another 10 million along a pipeline to the Faneromeni dam. The project is expected to cost 130 million euros and provide irrigation for an area of 45,000 square metres in this part of Crete threatened by desertification.
Today the situation in the Messara is worrying, as the mean temperature in January 2007 was three degrees higher (12 oC) than in January 2006 (9 oC), while the water table is 5-10 metres lower than in 2006, and up to 22 metres lower than in 2005 in some areas. A similar picture is seen in other areas such as Mt Dikti (the Lassithi Mountains).
Farmers say that the aquifer problem is so bad that seawater is already entering wells in the Tymbaki area. They are also afraid that this year’s warm weather will have a negative impact on olive oil production this season.
Crete’s Semi-arid Climate
What seems paradoxical is that in 2006 we had more rain in Crete than in 2005. According to an announcement by the Institute of Geology and Mineral Exploration, rainfall in 2005/06 was between 550 and 930 mm, while in 2006/07 it was 630 to 1280 mm. Yet although the percentage of rainfall was higher than the previous year, the groundwater has not been replenished because the rain came in short, heavy showers.
In October and November 2006 we had heavy rainfall in Crete which caused serious damage to crops, buildings and roads. The areas worst hit were Arvi and Psari Forada, Zaros and Rouvas Municipality, and especially Kalyves and Almyrida, where a person was actually drowned in the floods.
The climate of Crete is a “semi-arid” climate, one of whose features is that rain falls all at once in a few torrential showers. This means that the water runs off the surface of the earth without being absorbed properly and replenishing the aquifers. Evaporation is also very high due to the high temperatures, and about 8 cubic metres of water are lost per square kilometre of Cretan soil.
Based on its geographical position, Crete should have deserts like those of North Africa. The fact that we do not is due to a rare, delicate environmental balance in the region because our islands are surrounded by sea and, according to Herodotus, life-giving winds blow for 40 days in the summer: the famous meltemia that keep Cretan temperatures at bearable levels.
Crete and the Greenhouse Effect
Today the greenhouse effect has upset environmental balances all over the world. Based on data from European weather satellites, the greenhouse effect is expected to cause a temperature increase of 2 to 3 degrees Celsius, dramatically increasing desert areas and reducing crops in most parts of the Mediterranean, especially Crete.
Desertification has already made its appearance in Crete in the Asterousia Mountains, Lassithi (Ierapetra and Makrygialos) and Gavdos. The future is bleak, as 2007 may prove to be the hottest year recorded globally since records began.
The overheating of the planet is increasing worryingly, a fact confirmed by the UN World Meteorological Organization. Scientists predict that desertification will have a widespread impact with flooding and a dramatic decrease in cultivated areas.
The scientific community is particularly concerned by the significant drop in the water table. This water imbalance will be the most serious problem facing Crete in the near future. We will have to understand that climate change is the main, vital threat to the natural environment.
The phenomenon of desertification, already apparent in Crete and currently monitored by experts, can be countered by organized action in the framework of a wider awareness campaign. On a global level, according to report due to be made public in the next few days, methane and nitric oxide emissions produced by mines, agriculture and transport must be reduced. Scientist estimate that global emissions can be cut by up to 25% of 1990 levels by 2050.
If no measures are taken, according to the worst-case scenario, cultivable land in Southern Europe and of course Crete will shrink to a fifth of its present area in the 21st century, while the same countries will be vulnerable to wildfires. The North will become the new tourist attraction, with tourists enjoying a swim in the warm waters of the Baltic and the North Sea.
BY STEVE DANIELS
A recent three day scientific conference organized by the Agricultural University of Athens in Heraklion has concluded that half of Cretan land is at high risk of desertification. The over-intensive use of land, over-pumping of groundwater and overgrazing by thousands of sheep and goats are the main contributory factors.
In short we are using more water than we can afford and global warming is going to exacerbate the problem. Although we may have more rainfall in future this is likely to come in the form of torrential downpours which, without the vegetation to absorb it, will just run off the land and back to the sea.
This will have a serious effect on Cretan agriculture, one of the mainstays of our economy. Our other main industry, tourism, (another major user of water) will also be affected. If the situation remains unchecked then tourists, farmers and residents alike will face more frequent water cuts.
Steps are being taken with dams and reservoirs at various stages of planning and construction and new wells being bored but groundwater is falling daily. On the Messara plain where the mean temperature in January 2007 was three degrees higher (12 oC) than in January 2006 (9 oC), the water table is 5-10 metres lower than in 2006, and up to 22 metres lower than in 2005 in some areas. A similar picture is seen in other areas such as Mt Dikte (the Lassithi Mountains). Seawater is already entering wells in the Tymbaki area according to local farmers.
To say that the situation is now critical is an understatement. It is a problem which we are all facing and we all need to think more about the water we use. The British comedian, Alistair McGowan, in a recent television interview revealed that each time he shaves he runs the lukewarm water into a jug before it runs hot enough to shave. When he’s finished shaving he uses the water from the jug to rinse away the hairs rather than run the cold tap. The cumulative effect of all of us paying attention to small things like this could make an enormous difference.
One thing that I plan to do this summer is to fix guttering and a water butt. Like so many Cretan houses mine has a flat roof and the rainwater runs off into the courtyard through three short pipes, (often with considerable force last winter). If I can collect that water then I won’t need to use as much mains water for the garden.
Desertification is no longer something that you see on TV happening in other countries: it is happening here in Crete now. This summer may well be the hottest yet recorded so if we want to continue to have water “on tap” then we’ll all have to work together to conserve what precious little we have.
Steve Daniels is a writer and amateur naturalist living near Ierapetra on the south east coast. His books are published by Little Lemur Publishing.