Iran: decades of unsustainable water use

Iran: decades of unsustainable water use

Zahra Kalantari; Davood Moshir Panahi, and Georgia Destouni, all three of Stockholm University studied Iran surface waters concluded the decades of unsustainable water use has dried up lakes and caused environmental destruction.


Salt storms are an emerging threat for millions of people in north-western Iran, thanks to the catastrophe of Lake Urmia. Once one of the world’s largest salt lakes, and still the country’s largest lake, Urmia is now barely a tenth of its former size.

As the waters recede, extensive salt marshes are left exposed to the wind. These storms are getting saltier and are now happening more often – even in the cold and rainy seasons of the year. As more drying uncovers more salt marshes, things will only get worse.

Salt storms pose a direct threat to the respiratory health and eyesight of at least 4 million people living in both rural and urban areas around Lake Urmia. Increasing soil salinity reduces the yield of agricultural and orchard crops grown around the lake, while the lake has shrunk so much that boating is no longer possible, resulting in a loss of tourism. https://youtu.be/H7euP07yEA0

Urmia 1986-2016. Salt marshes have been exposed as the lake has shrunk. (Source: Google Timelapse)

This dramatic decline is down to human activity. Over the past three decades, Iran has followed a succession of five-year economic development plans, part of which involved providing large government loans for the agricultural sector to expand and switch from being primarily rain-fed to irrigated. To provide the necessary water for the farms, as well as for growing domestic and industrial use, more than 50 dams were constructed on rivers that drain much of north-western Iran and flow into the lake.

While these dams siphoned off the water that once fed the lake, the drying process was intensified by climate change. The rate of rainfall has reduced in recent decades and the Urmia basin has experienced several multi-year droughts.

All this has left a massively shrunken lake and a host of associated economic, social and health impacts. Yet what’s happening with Lake Urmia is just one example of water-environmental problems emerging right across Iran.

Iran is getting warmer and drier

In a recent journal article, we examined how both climate change and human activity had affected hydrological changes in Iran in recent decades. The country has 30 main river basins, and we gathered three decades of key hydro-climatic data for each, including surface temperature, precipitation, how much water was stored underground in soil and rock, surface runoff (the amount of excess rainwater that cannot be absorbed by the soil), and measures of evaporation and transpiration from plants.

We then calculated the average values of each of these variables over two 15-year periods, 1986-2001 and 2002-2016, and compared the two. This allowed us to see what was changing in each of these basins and by how much.

Our work showed that Iran’s main river basins have got warmer but are receiving less precipitation, are storing less water underground, and seeing less runoff.

Rusting boat on salty ground, lake and mountains in distance.
A boat is left to rust as Lake Urmia shrinks. Tolga Subasi / shutterstock

Some river basins where precipitation and runoff decreased still saw an increase in evapotranspiration (the sum of evaporation and plant transpiration). This may seem odd at first, as less rainwater surely means there is less water to evaporate or for plants to transpire. Lake Urmia, for instance, is an endorheic basin, which means nothing flows out of it and all water that flows in eventually evaporates (this is why the lake is salty). But why would evapotranspiration have actually increased, even as the basin is fed by less water?

This is actually an indicator of human activity. First, all those dams generally increase the surface area of the body of water, compared to the natural flow before the dam was built. Artificial lakes and reservoirs, therefore, leave more water exposed to air and direct sunlight, thus increasing evaporation.

But it’s also down to farming. As more crops are grown, more water is transpired by plants – and more water is needed to grow those plants. To add water where needed, farmers have turned to groundwater and large-scale water transfer engineering projects.

This use of water to maintain and expand human activities is unsustainable and has serious environmental and socio-economic consequences, particularly in this dry part of the world, as seen by changes to Lake Urmia. Policymakers need to mitigate the adverse hydrological changes and associated socio-economic, environmental and health impacts, and move towards something more sustainable.

Zahra Kalantari, Associate Professor, Stockholm University; Davood Moshir Panahi, PhD Student, Department of Physical Geography, Stockholm University, and Georgia Destouni, Professor of Hydrology, Hydrogeology and Water Resources, Stockholm University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The Conversation

The Conversation

Point Of Use Water Purifier (POU) Market In MENA

Point Of Use Water Purifier (POU) Market In MENA

An article Posted by Ankush on July 31, 2020, is on the Point Of Use Water Purifier (POU) Market In MENA (Middle East & North Africa). It is as witnessed by a CAGR of 7.6% by 2020 per Future Market Insights (FMI) Estimates. All despite these years the most severe threat facing the MENA, there exists a market of Point Of Use Water Purifier (POU).

Point Of Use Water Purifier (POU) Market In MENA

Future Market Insights report examines the ‘POU Water Purifier Market’ in Middle East and North Africa region for the period 2014–2020. The primary objective of the report is to offer key insights about water purifier market in MENA to current market participants or new entrant’s participants across the value chain.

Report includes study of the three key technologies of water purification i.e. Reverse Osmosis (RO),

Ultra Violet (UV) and Media filtration (Gravity). Report offers in depth analysis of market size, forecast and the key trends followed in all three segments.

The report starts with an overview of parent market i.e. water treatment industry in MENA and the part POU water purifier industry plays in it. Report also offer useful insights about global POU water purifier market and the role MENA market is posed to play.

Next section of the report includes FMI analysis of the key trends, drivers and restraints from supply side, demand side and economic perspective, which are influencing the target market. Impact analysis of key growth drivers and restraints based on weighted average model included in the report better equips and arms client with crystal clear decision making insights.

As highlighted before, water purifiers are based Reverse Osmosis (RO), Ultra Violet (UV) and media based filtration technology. Reverse osmosis is estimated to contribute noteworthy proportion of revenue in MENA water purifiers market. However, in the price sensitive regions, media based segment is expected to witness robust growth during the forecast period.

The next section highlights POU water purifier market by region. It provides market outlook for 2014- 2020 and sets forecast within context of water purifier market, including the three technologies to build out a complete picture at regional level. This study discusses the key regional trends contributing to the growth of the water purifier market in MENA as well as analyses the degree at which key drivers are influencing water purifiers market in each region of MENA. For this report, regions assessed are Kingdom of Saudi Arabia, United Arab Emirates, Turkey, Israel, Egypt, Algeria and rest of MENA.

Gain complete access to the report@ https://www.futuremarketinsights.com/reports/mena-pou-water-purifiers-market

To calculate the revenue generated from POU water purifiers, the report considered total volume sales of water purifier along with the average selling price, and also the revenue generated from water purifier segment of major players in the market. When forecasting market, the starting point is sizing the current market, which forms the basis for how market will develop in future. Given the characteristics of market, we triangulated the outcome of three different type of analysis based on supply side, consumer spending, and economic envelope. However, forecasting the market in terms of various water purifier technologies and regions is more matter of quantifying expectations and identify opportunities rather than rationalizing them after the forecast has been completed.

Also another key feature of report is analysis of the three key technologies of water purifier and regions in terms of absolute $ opportunity. This is traditionally overlooked when analyst forecasts the market. But absolute $ opportunity is critical in assessing the level of opportunity that a provider can look to achieve, as well as to identify potential resources from both the sales and delivery perspective.

Further to understand key growth segments in terms of technology and region FMI developed the MENA water purifier market attractiveness index. The resulting index should help providers identify real market opportunities.

In the final section of report, MENA water purifier market competitive landscape is included to provide report audience with dashboard view based on categories of provider in value chain, presence in water purifier market and their key differentiators. Key categories of providers covered in the report are manufacturers and major distributors. This section is primarily designed to provide client with an objective and detailed comparative assessment of key providers specific to market segment in the POU water purifier value chain. Report audiences gain segment and function specific vendor insight to identify and evaluate key competitors based on in depth assessment and capabilities and success in the POU water purifier market place. Detailed profiles of the providers are also included as scope of the study to evaluate their long term and short term strategies, key offerings and recent developments in the market. Key competitors covered are Eureka Forbes, PureIt, Strauss Water, Panasonic, LG and others.

In this study, we analyze the MENA Water Purifier Market during 2012-2020. We focus on:

  • Market size and forecast, 2012-2020
  • Key drivers and developments in POU Water Purifier Market
  • Key Trends and Developments of MENA Water Purifier Market technologies such as RO,UV and Media
  • Key Drivers and developments in particular regions such as KSA, UAE, Turkey ,Israel, Egypt, Algeria and Others

Tiny plants crucial for sustaining dwindling water supplies

Tiny plants crucial for sustaining dwindling water supplies

UNSW MEDIA produced this summary of their on Tiny plants crucial for sustaining dwindling water supplies: a global analysis on 31 July 2020. Could the wisdom of such an endeavour be replicated onto the whole or part of the MENA region?


The image above is of A diverse biocrust community in western New South Wales. Photo: David Eldridge

Miniscule plants growing on desert soils can help drylands retain water and reduce erosion, UNSW researchers have found.

global meta-analysis led by UNSW scientists shows tiny organisms that cover desert soils – so-called biocrusts – are critically important for supporting the world’s shrinking water supplies. 

Biocrusts are a rich assortment of mosses, lichens, cyanobacteria, and microscopic organisms such as bacteria and fungi that live on the surface of dryland soils. Drylands, collectively, are the world’s largest biome.

“Biocrusts are critically important because they fix large amounts of nitrogen and carbon, stabilise surface soils, and provide a home for soil organisms,” said lead author Professor David Eldridge from UNSW Science.

“But we still have a poor understanding of just how biocrusts influence hydrological cycles in global drylands. 

“Accounting for biocrusts and their hydrological impacts can give us a more accurate picture of the impacts of climate change on dryland ecosystems and improve our capacity to manage those effects,” Prof. Eldridge said.

Scientists are using disc permeameters to measure the effect of biocrusts on the infiltration of water in a semi-arid woodland in western New South Wales Photo: David Eldridge
Exploring more than 100 scientific papers

For the study, the team assembled and then analysed the largest ever global database of evidence on the effects of biocrusts on water movement, storage and erosion, focussing on drylands. 

“Our emphasis was on dryland soils because biocrusts are often the dominant surface covering on these soils, particularly during dry times,” Prof. Eldridge said. 

A huge increase in the number of publications on biocrusts over the past decade had prompted the group to critically assess the links between water capture and storage, and landscape stability in drylands. 

Co-author Dr Samantha Travers from UNSW Science helped retrieve and analyse data from more than 100 scientific papers published over the past 30 years. 

“The global literature on biocrust effects on hydrology has often been conflicting, preventing us from making broadscale recommendations on how to manage them to manage water,” Dr Travers said. 

Importantly, the researchers showed that globally, the presence of biocrusts on the soil surface reduced water erosion by an average of 68 per cent. 

“Cyanobacteria in the crusts secrete organic gels and polysaccharides that help to bind small soil particles into stable surfaces. Mosses in the crusts also trapped water and sediment on the soil surface, preventing the removal of soil particles,” Dr Travers said.

Although biocrusts reduced the infiltration of water into the soil, they tended to increase water storage in the uppermost layers. 

“This upper layer is where most of the nutrients and microbes are found – it is a critical zone for plant production and stability in dryland soils,” Prof. Eldridge said.

“More water in the upper layers means greater productivity and stability.”

Prof. Eldridge said we now had a better understanding of how biocrusts affect water relations in drylands.

“However, the effects depend on factors such as the type of crust and whether it is intact or disturbed,” he said.

Thin fungal filaments associated with biocrusts stick to soil particles, increasing soil stability and altering water flow. Photo: David Eldridge
Three decades of biocrust research

Prof. Eldridge and his team have been studying the role of biocrusts on Australia’s soils for more than 30 years. 

The focus of the team’s research is on drylands because they occupy almost half of Earth’s land surface and support almost 40 per cent of the global human population. 

“Many people in drylands rely on pastoralism for their livelihoods, so the capture and use of water is critically important in these water-limited environments,” Prof. Eldridge said.

“Anything that alters the hydrological balance in drylands has the potential therefore to affect millions of people, hence the importance of these tiny surface communities.”

He said a major problem for sustainable management of drylands was overgrazing by livestock. 

“Trampling by sheep and cattle breaks up the crust, destabilising the soil surface and leading to increased water erosion – effects that are supported by our global analyses,” he said. 

“Preventing overgrazing by livestock is critical if we are to prevent the loss of biocrusts, but until recently, the magnitude of the effects have not been known.

“The results of this work will be incorporated into global water balance and soil loss models so that managers and governments have a better understanding of the implications of losing biocrusts on the world’s dwindling water supplies,” Prof. Eldridge said. 

The study, published in Global Change Biology today, was a collaborative effort between UNSW Sydney, and scientists from the United States, Spain, Germany, Mexico and China.

The work is part of a larger global study, supported by the John Wesley Powell Center for Analysis and Synthesis to predict the impacts of climate change on biological crust communities.

The research team is now examining how global land-use changes affect biocrust communities and developing best management practices to restore biocrusts as we move towards a hotter and drier world. 

Multi-million national green growth plan launched

Multi-million national green growth plan launched

A Multi-million national green growth plan launched today is reported in this article of the Jordan News Agency.

Amman, July 6 (Petra) — Jordan on Monday launched a multi-million ambitious green growth plan as part of a broader national drive towards a green economy and sustainable development.

The six-pronged 2021-2025 National Green Growth Plan, which was announced by Minister of Environment and Agriculture Saleh Kharabsheh, comprises executive plans targeting the key sectors of water, waste management, energy, agriculture, tourism and transport.

In part, the blueprint is intended to help build sustainable sectors that are more resilient and adaptive to adverse phenomena, including climate change and the fallout of emergencies, such as the coronavirus pandemic. It was drawn up in collaboration with the Global Green Growth Institute (GGGI).

Kharabsheh told a teleconference with government representatives and global stakeholders that the plan is designed to ensure alignment between green growth, climate change and sustainable development goals within the sectoral strategic framework.



Marshall Brown, Senior Officer/ Jordan Program at the GGGI, underlined the importance of multi-stakeholder cooperation to translate the plan on the ground, and said that the private sector and international partners have a key role to support this effort.

In the energy sector, the plan envisages the development of a smart electric grid, backing the Jordan Renewable Energy and Energy Efficiency Fund’s bid for the Green Climate Fund’s accreditation and a public-private partnership for the construction of EV charging stations at a total cost of $85 million.

The plan sets $965 million as the total cost of water projects, which include the rollout of a financial mechanism to support water harvesting projects, in addition to carrying out a technical project to rationalize industrial water use. Also in the water sector, the plan envisages the construction of an industrial wastewater treatment plant in Zarqa.

With regard to waste management, the plan includes the establishment of an excellence center for waste management, research and development, a feasibility study for the launch of projects aimed at separating organics from municipal solid waste, and finally a pilot project on the extended producer responsibility in the e-waste sector. The total cost of projects in the waste management sector is put at $248 million.

Turning to agriculture, the plan includes an information management and communication capacity-building project within the green growth framework. It also pursues a resource management project in the production of olive and olive oil. Other key projects in this area includes investing in hydroponics and a national afforestation project. The combined cost of these projects stands at $194 million.

Another key focus of the plan is the transport sector, where the total project cost is envisioned at $167 million. The projects in this domain include the rollout of smart transport systems, the establishment of a transport excellence center and the introduction of environmentally-friendly transport solutions in Irbid, Zarqa and Madaba.

As for tourism, the plan contains a set of ambitious projects, which include the establishment of an excellence center aimed at developing the tourism industry and maximizing ecotourism in protected areas, as well as a project for resource rationalization in the tourism and hospitality sectors for a total cost of $173 million.

//Petra// AA

Can Egypt, Ethiopia and Sudan find a way forward?

Can Egypt, Ethiopia and Sudan find a way forward?

The Nile and the dam: Can Egypt, Ethiopia and Sudan find a way forward? Wondered Daniel C. Stoll in Middle East Eye of 2 July 2020 before adding: Since it began construction in 2011, Ethiopia has been at odds with its downstream neighbours, especially Egypt, over the Renaissance Dam’s very existence.

The image above is of the Grand Ethiopian Renaissance Dam as pictured on 26 December (AFP).

As Ethiopia moves closer to filling the reservoir behind the Grand Ethiopian Renaissance Dam (GERD), parties are frantically searching for a way to decrease tensions and ensure that negotiations – not sabre-rattling – help Egypt, Ethiopia and Sudan find a way forward. 

The window for finding a resolution, however, appears to be closing quickly.

Ethiopia has long said that it would use the onset of its rainy season in July to begin filling the dam’s reservoir. Since it began construction in 2011, Ethiopia has been at odds with its downstream neighbours, especially Egypt, over the dam’s very existence. 

Existential threat

While Ethiopia touts the $4.6bn GERD as a key to the country’s development and a source of cheap electricity for Ethiopia and its neighbours, Egypt claims the dam represents an existential threat that will choke off the Nile’s flow into Egypt and imperil its citizens.

Despite the bellicose rhetoric from the two countries and the constant exchange of threats and counter-threats, Egypt, Ethiopia and Sudan have managed over the years to talk through their differences and agree on many key issues. In 2015, they inked a Declaration of Principles, committing all three countries to cooperation on the dam’s construction and to the peaceful resolution of any disagreements that might arise.

Each has too much to lose to let conditions within the Nile River Valley reach a point of outright conflict

While relations among the three riparian states in subsequent years have been marked more by acrimony than agreement, they did come together for talks coordinated by the US Department of Treasury and the World Bank in late 2019 and early 2020. These talks produced a draft agreement containing a number of key points related to the dam and its reservoir (estimated to hold more than 74 billion cubic metres of water).  

Sudan’s foreign minister, Asmaa Mohamed Abdalla, said in a letter to the UN Security Council on 2 June that the talks had produced 90 percent of an agreement. Just before the three countries were scheduled to initial the draft agreement in late February, however, Ethiopia refused to accept it, and the threats and recriminations resumed.

Unresolved issues

Left unresolved are two key issues: the current lack of any drought mitigation protocols and the absence of any dispute resolution process.

Since Egypt receives almost 98 percent of its freshwater for agricultural, industrial and municipal uses from the Nile, the country insists that Ethiopia must commit to releasing a specific amount of water during periods of prolonged drought to ensure a consistent and predictable flow into Egypt. Both Sudan and Egypt also insist on a clear process for resolving disputes over the operation of the dam.

Workers move iron girders from a crane at the GERD on 26 December (AFP)
Workers move iron girders from a crane at the GERD on 26 December (AFP)

For its part, Ethiopia insists that committing a specified volume of water during periods of drought will ultimately drain the reservoir, thereby impeding Ethiopia’s ability to generate the electricity it badly needs. It also believes that Egypt is trying to perpetuate what it regards as Egypt’s unfair claim to substantial amounts of the Nile’s waters.

Since February, several outside players – including the EU, US and South Africa (as head of the African Union) – have tried to bring the riparian states back to the negotiating table, but with little success.  

In early April, Ethiopia proposed a two-year interim agreement, arguing it would help reduce tensions and rebuild trust. Egypt rejected the proposal, however, asserting that an incremental approach would allow Ethiopia to avoid agreeing to a more comprehensive approach. Sudan also insists on a comprehensive agreement.

Diplomatic solution

In a further attempt to pursue a diplomatic solution, both Sudan and Egypt have asked the UN Security Council to take up the issue under Article 35 of the UN Charter. UN Secretary-General Antonio Guterres has said that the UN stands ready to help the parties come to an agreement

While a Security Council debate may eventually identify a way forward, the council’s deliberate modus operandi is unlikely to produce any dramatic breakthrough in the short term. Both Ethiopian Prime Minister Abiy Ahmed and Egyptian President Abdel Fattah al-Sisi are facing considerable pressure within their respective countries to “hang tough” and not be seen as compromising on issues of such vital national interest. Why the US wants to avert conflict over the NileRead More »

It is unclear how the council would create conditions for compromise, and yet compromise the three states must do. Each has too much to lose to let conditions within the Nile River Valley reach a point of outright conflict.

Sudan could benefit greatly from access to the cheap and abundant electricity that the GERD is expected to provide. It also needs assurances that nothing will affect the Nile’s flow into Sudan and impede the operation of its Roseires Dam.

While Ethiopia appears to have the upper hand in this situation – given its growing economy and the strategically important position it occupies along the river – it, too, needs some kind of negotiated solution. A diplomatic solution would deepen its already growing influence in the basin and enhance its credentials as the dominant power in the region – a consideration that appears at the forefront of Abiy Ahmed’s strategic calculus. It would help reassure potential buyers of GERD’s electricity that Ethiopia is a trusted and reliable partner.

Difficult compromise

For Egypt, the stakes are obvious: other than a modest amount of groundwater, Egypt has no other ready source of water for its rapidly expanding population (currently 102 million and estimated to be growing at a rate of 1.94 percent a year).  

A negotiated agreement would also most likely give Egypt, and Sudan as well, access to important technical and environmental data related to the Nile’s flow and conditions in the basin upstream, information crucial for making informed decisions on water policy.

All countries would benefit from a less bellicose geopolitical environment within the basin, but compromise will be difficult

Finally, achieving some kind of resolution to this particularly thorny issue would allow the Sisi government to focus on an expanding number of domestic and foreign policy challenges, including increasingly tense relations with Libya, as well as growing domestic political and social unrest.

All countries would benefit from a less bellicose geopolitical environment within the basin, but compromise will be difficult. Egypt will need to recognise that Ethiopia has a right to pursue its ambitious development schemes, while acknowledging Ethiopia’s growing influence in the basin specifically and the Red Sea region more generally – influence that will come at the expense of Egypt’s long-held dominance in the region.

For its part, Ethiopia will need to recognise the precarious position of its downstream neighbours, particularly Egypt, and provide credible reassurances that it will release sufficient amounts of water during periods of drought.

Senior leadership

While Ethiopia has long resisted bringing in third parties to help facilitate negotiations, it is possible that the African Union could play a constructive role in this regard. Egypt would have to overcome its reluctance to giving the AU a more dominant role, but having the AU involved in negotiations would be in keeping with Egypt’s long-held demand for outside intervention.

Ultimately, the time might have come for negotiations to go beyond the ministerial level and involve instead the heads of government. To date, negotiations have generally involved the respective ministers of irrigation or water. Achieving a resolution to these final, contentious issues may well require the direct participation of the senior political leadership of each country.

The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Middle East Eye.

Daniel C. StollDaniel C Stoll is Associate Dean for Global Affairs at St Norbert College in the US. He is the co-author most recently of International Conflict Over Water Resources in Himalayan Asia (Palgrave Macmillan) and has written extensively on issues of water resources management in Africa and the Middle East.

Why the Mediterranean is a climate change hotspot

Why the Mediterranean is a climate change hotspot

The Massachusetts Institute of Technology asking Why the Mediterranean is a climate change hotspot came up with A new analysis uncovers the basis of the severe rainfall declines predicted by many models.

17 June 2020

Although global climate models vary in many ways, they agree on this: The Mediterranean region will be significantly drier in coming decades, potentially seeing 40 percent less precipitation during the winter rainy season.

An analysis by researchers at MIT has now found the underlying mechanisms that explain the anomalous effects in this region, especially in the Middle East and in northwest Africa. The analysis could help refine the models and add certainty to their projections, which have significant implications for the management of water resources and agriculture in the region.

The study, published last week in the Journal of Climate, was carried out by MIT graduate student Alexandre Tuel and professor of civil and environmental engineering Elfatih Eltahir.

The different global circulation models of the Earth’s changing climate agree that temperatures virtually everywhere will increase, and in most places so will rainfall, in part because warmer air can carry more water vapor. However, “There is one major exception, and that is the Mediterranean area,” Eltahir says, which shows the greatest decline of projected rainfall of any landmass on Earth.

“With all their differences, the models all seem to agree that this is going to happen,” he says, although they differ on the amount of the decline, ranging from 10 percent to 60 percent. But nobody had previously been able to explain why.

Tuel and Eltahir found that this projected drying of the Mediterranean region is a result of the confluence of two different effects of a warming climate: a change in the dynamics of upper atmosphere circulation and a reduction in the temperature difference between land and sea. Neither factor by itself would be sufficient to account for the anomalous reduction in rainfall, but in combination the two phenomena can fully account for the unique drying trend seen in the models.

The first effect is a large-scale phenomenon, related to powerful high-altitude winds called the midlatitude jet stream, which drive a strong, steady west-to-east weather pattern across Europe, Asia, and North America. Tuel says the models show that “one of the robust things that happens with climate change is that as you increase the global temperature, you’re going to increase the strength of these midlatitude jets.”

But in the Northern Hemisphere, those winds run into obstacles, with mountain ranges including the Rockies, Alps, and Himalayas, and these collectively impart a kind of wave pattern onto this steady circulation, resulting in alternating zones of higher and lower air pressure. High pressure is associated with clear, dry air, and low pressure with wetter air and storm systems. But as the air gets warmer, this wave pattern gets altered.

“It just happened that the geography of where the Mediterranean is, and where the mountains are, impacts the pattern of air flow high in the atmosphere in a way that creates a high pressure area over the Mediterranean,” Tuel explains. That high-pressure area creates a dry zone with little precipitation.

However, that effect alone can’t account for the projected Mediterranean drying. That requires the addition of a second mechanism, the reduction of the temperature difference between land and sea. That difference, which helps to drive winds, will also be greatly reduced by climate change, because the land is warming up much faster than the seas.

“What’s really different about the Mediterranean compared to other regions is the geography,” Tuel says. “Basically, you have a big sea enclosed by continents, which doesn’t really occur anywhere else in the world.” While models show the surrounding landmasses warming by 3 to 4 degrees Celsius over the coming century, the sea itself will only warm by about 2 degrees or so. “Basically, the difference between the water and the land becomes a smaller with time,” he says.

That, in turn, amplifies the pressure differential, adding to the high-pressure area that drives a clockwise circulation pattern of winds surrounding the Mediterranean basin. And because of the specifics of local topography, projections show the two areas hardest hit by the drying trend will be the northwest Africa, including Morocco, and the eastern Mediterranean region, including Turkey and the Levant.

That trend is not just a projection, but has already become apparent in recent climate trends across the Middle East and western North Africa, the researchers say. “These are areas where we already detect declines in precipitation,” Eltahir says. It’s possible that these rainfall declines in an already parched region may even have contributed to the political unrest in the region, he says.

“We document from the observed record of precipitation that this eastern part has already experienced a significant decline of precipitation,” Eltahir says. The fact that the underlying physical processes are now understood will help to ensure that these projections should be taken seriously by planners in the region, he says. It will provide much greater confidence, he says, by enabling them “to understand the exact mechanisms by which that change is going to happen.”

Eltahir has been working with government agencies in Morocco to help them translate this information into concrete planning. “We are trying to take these projections and see what would be the impacts on availability of water,” he says. “That potentially will have a lot of impact on how Morocco plans its water resources, and also how they could develop technologies that could help them alleviate those impacts through better management of water at the field scale, or maybe through precision agriculture using higher technology.”

The work was supported by the collaborative research program between Université Mohamed VI Polytechnique in Morocco and MIT.


Story Source: Materials provided by Massachusetts Institute of Technology. Original written by David L. Chandler. 

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