New research shows Iran’s most famous lake has shrunk by nearly 90% since the 1970s. Scientists urge action

In the late 1990s, Lake Urmia, in north-western Iran, was twice as large as Luxembourg and the largest salt-water lake in the Middle East. Since then it has shrunk substantially, and was sliced in half in 2008, with consequences uncertain to this day, by a 15-km causeway designed to shorten the travel time between the cities of Urmia and Tabriz.

Historically, the lake attracted migratory birds including flamingos, pelicans, ducks and egrets. Its drying up, or desiccation, is undermining the local food web, especially by destroying one of the world’s largest natural habitats of the brine shrimp Artemia, a hardy species that can tolerate salinity levels of 340 grams per litre, more than eight times saltier than ocean water.

Effects on humans are perhaps even more complicated. The tourism sector has clearly lost out. While the lake once attracted visitors from near and far, some believing in its therapeutic properties, Urmia has turned into a vast salt-white barren land with beached boats serving as a striking image of what the future may hold.

Desiccation will increase the frequency of salt storms that sweep across the exposed lakebed, diminishing the productivity of surrounding agricultural lands and encouraging farmers to move away. Poor air, land, and water quality all haveserious health effects including respiratory and eye diseases .

The people of the north west – mainly Azeris and Kurds – are raising their voices. The Azeris, one of Iran’s most influential ethnic groups and about a third of the country’s population, venerate Urmia as a symbol of Azeri identity, dubbing it “the turquoise solitaire of Azerbaijan”. The region is also home to many Kurds, who are demanding a bigger say in the management of the lake to improve the livelihood of Kurdish communities.

President Hassan Rouhani has shown he is listening, referring to Urmia during his election campaign, and subsequently promising the equivalent of $5 billion to help revive the lake over ten years. Solutions, however, require agreement on the main causes of the problem, and this motivated a group of concerned Iranian researchers in the United States, Canada, and United Kingdom to carry out an independent, first-hand assessment beginning in 2013. Because of the unavailability of reliable and consistent ground-truth data, the team used high-resolution satellite observations over the past four decades to estimate the lake’s physiographic changes.

The results of this investigation, which recently appeared in the Journal of Great Lakes Research, revealed that in September 2014 the lake’s surface area was about 12% of its average size in the 1970s, a far bigger fall than previously realised. The research undermines any notion of a crisis caused primarily by climate changes. It shows that the pattern of droughts in the region has not changed significantly, and that Lake Urmia survived more severe droughts in the past.

The lake’s surface area naturally varies to some extent between wet and dry seasons and the situation has eased somewhat with seasonal precipitation that occurred since September. But the magnitude and timeline of the shrinkage ­– frequently attributed by the Iranian water authorities to years of below-average precipitation – are unquestionably beyond the ordinary, and suggest that the lake may have reached a “tipping point” leading to sudden death. If Lake Urmia is to be revived, the authorities must look urgently at the construction of dams and irrigation projects designed to boost agri-business and meet growing regional water demand.

The tragic demise of the Aral Sea in central Asia is a chilling precedent. Once one of the world’s largest lakes, the Aral Sea faded away due to diversion of water for agriculture from its tributaries, the Amu Darya and Syr Darya rivers. The Aral Sea became a hallmark of poor agricultural water management in the Soviet era. Over the course of five decades its surface area dropped to less than 10% of its original extent in the 1960s

It is ironic that the collapse of Lake Urmia and other Iranian water bodies such as Shadegan, Gav-Khuni, Bakhtegan, Anzali, and Hamouns comes in the country where the 1971 Ramsar Convention was signed. As a pioneering intergovernmental treaty for conservation and sustainable use of wetlands, Ramsar envisaged action by both national governments and international co-operation.

Just five years later, in 1976, UNESCO (the United Nations Educational, Scientific and Cultural Organisation) designated Lake Urmia a biosphere reserve toencourage sustainable development grounded in community involvement and sound science.

Given the far-reaching socio-economic effects, and human health impacts that may extend beyond Iran’s borders, Lake Urmia’s collapse requires active involvement of international organisations that can provide expertise and financial resources, even if their efforts to help are complicated by sanctions blocking financial transactions. These include UNESCO, the United NationsDevelopment Programme (UNDP), the Global Environment Facility (GEF), the World Bank, World Climate Research Programme (WCRP), European Commission Joint Research Centre (JRC) and World Health Organization (WHO).

On the bright side, growing public awareness about water scarcity, mismanagement and waste may pave the way for re-establishing a balance between natural water supply and water demand. The three provinces that share the Lake Urmia basin – East Azerbaijan, West Azerbaijan, and Kurdistan – and the Iranian government have joined forces to devise promising restoration ideas, including stopping dam construction, managing the existing reservoirs and regulating the use of the agricultural lands. Such changes could augment the lake’s inflow, limit additional surface water and groundwater withdrawal, and mitigate salt blowouts and sand storms.

However, this is barely enough for any realistic optimism. Demand-side management plans to reduce the basin’s water use must go in effect immediately, and proposals for water transfer – which have had harmful ecological and socio-economic side-effects in other parts of Iran – need drastic revision. There is an obvious need, too, for schemes to compensate current water-users for any losses.

While international help is important, Iranians must lead restoration efforts, for Lake Urmia and other water bodies. Iran’s push for development is taking a toll on the nation’s water resources in a mostly arid and semi-arid country as short-sighted projects transfer water to supply inefficient agriculture and growing urban areas. Without a pragmatic action plan, the country faces severe water stress.

The authors were all involved in the independent investigation of Lake Urmia. Ali Mirchi is a postdoctoral research associate at the Department of Civil and Environmental Engineering, Michigan Technological University; Kaveh Madani is a lecturer in Environmental Management at the Centre for Environmental Policy, Imperial College London; Amir AghaKouchak is an assistant professor at the Department of Civil and Environmental Engineering, University of California, Irvine

theguardian.com