Permian basalt columns along the Corsican shore (Scandola, N Corsica, 2001). © BRGM - Eric Palvadeau

Water security around the Mediterranean in the context of global change

02.04.2019
Water scarcities, overabstraction from water tables and shrinking resources combined with increasing demand from a growing population, agriculture and economic growth: this is the situation around the Mediterranean in the context of climate change that BRGM researchers are addressing in studies ranging from socio-economics to aquifer functioning.

The Ibn Batuta dam reservoir downstream from the Tleta basin (Morocco) has supplied drinking water to Tangier since 1977. Its initial 45 m3 storage capacity has now shrunk to 30 m3 due to an annual siltation rate equivalent to 1% of the entire volume of the reservoir. © BRGM - C. Hérivaux

The Ibn Batuta dam reservoir downstream from the Tleta basin (Morocco) has supplied drinking water to Tangier since 1977. Its initial 45 m3 storage capacity has now shrunk to 30 m3 due to an annual siltation rate equivalent to 1% of the entire volume of the reservoir. © BRGM - C. Hérivaux

The stakes are as high as the problems are enormous: over and above the unstable geopolitical context, water security around the Mediterranean has become a challenge that politicians and scientists alike must take great care to anticipate.

If we do not act now, the scene is already set for a crisis of major proportions. With nearly one fifth of the world’s current population already living in areas of water scarcity, the United Nations Environment Programme is predicting that over 2 billion people will be living with high water stress by 2050. The regions most concerned are the Mediterranean countries of North Africa and the Middle East, which already have the world’s lowest quantity of water per inhabitant and where the risks of water scarcity are likely to worsen, bringing social and economic consequences and conflicts that can easily be imagined.

Global, environmental and climate changes are worsening the situation: an uncertain and variable climate, pressure from pollutants and extreme weather events are increasing tensions over water resources at an unprecedented rate.

An inflatable weir on the Gapeau river that can be moved when the river is in spate to  keep the water table level down and prevent saline intrusion. © BRGM

An inflatable weir on the Gapeau river that can be moved when the river is in spate to keep the water table level down and prevent saline intrusion. © BRGM

An explosive cocktail

These water issues are creating an explosive cocktail. The development of irrigated agriculture is drawing heavily on groundwater in some North African countries. Although intensive groundwater use together with the rapid and large-scale deployment of private water wells and boreholes has
boosted economic development in the agricultural sector, this has many adverse environmental consequences: depleted water tables, degraded water and soil quality and saltwater intrusions, the latter being an irreversible phenomenon that could worsen with climate change. Farmers who have come to depend on intensive irrigation are in turn becoming increasingly vulnerable. In addition, groundwater use is also increasing with the development of tourism.

In the words of BRGM scientists, “if we do not act now, the current water crisis around the Mediterranean can be expected to trigger a food and agricultural crisis as well”.

520 million inhabitants in the Mediterranean Basin by 2020, a 2 to 4°C increase in temperatures and a 4 to 30% drop in rainfall by 2050

Multidisciplinary studies

It is clearly urgent to gain a thorough understanding of these risks and their impacts in order to support policy-making. This requires multidisciplinary scientific studies, and new policies for managing these areas need to be tested.

This is why the BRGM is conducting research on long-term assessments of water availability and quality, with pilot sites in the coastal zones of Morocco, Algeria, Tunisia, Greece and France. This is the aim of the Eranet-Med MEDAQCLIM project, for which a new technique for modelling transport processes has been developed and adapted to heterogeneous aquifers.

Researchers are also working to better understand the factors that determine water consumption and to predict how they are likely to evolve in the medium and long-term, especially in cities. These studies aim in particular to quantify uncertainties as to future needs, using probabilistic approaches. Strategies for adaptation to global changes are being developed and tested at different scales, with the players concerned involved in their design. Under the ALMIRA projet, the BRGM investigated the repercussions of different patterns of agricultural land use in Morocco on surface run-off and erosion risks in conditions of extreme rainfall.

In a word, the BRGM is fully involved in the problem of water security in the Mediterranean and may be one of the scientific players in charge of implementing the roadmap for the next decade developed by PRIMA, the Euro Mediterranean partnership for research and innovation, which focuses on water resources, agriculture and food.

Salinity map of the alluvial lower Gapeau water table in the spring of 2003, simulated by a gridded model. © BRGM

Salinity map of the alluvial lower Gapeau water table in the spring of 2003, simulated by a gridded model. © BRGM

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