Climate and human influence conspired in Lake Urmia’s decline


Climate and human influence conspired in Lake Urmia’s decline

Gepubliceerd op
10 november 2016

Lake Urmia in Iran was once the second-largest saltwater lake in the world. However, it has been sharply drying up over the last two decades. The surface area of Lake Urmia has been reduced by 80% over the last few decades. A study by Somayeh Shadkam and Fulco Ludwig from Wageningen University and several other researchers, just published in the Journal of Great Lakes Research indicates that this is caused by a combination of water withdrawals for irrigation and climate change.

Lake Urmia, a UNESCO Biosphere Reserve, once measuring over 464,000 hectares, is the largest inland lake in Iran. It is one of the largest saline lakes in the world and is an important habitat for birds and marine life, including unique crustaceans. The desiccation of the lake is a process that has been going on for several decades caused by high levels of evaporation and a reduced supply of water due to the damming of the rivers that feed the lake. This study presents the first scientific research into the relationship between this desiccation, water resources management and climate change.

A previous study by Shadkam et al. showed that future climate change will hamper any efforts to return the lake to its original state. Scenario studies indicated that these problems will only become more severe in the future. A new study has combined climate change research with water use research for the very first time and is supported by data collected between 1960 and 2010. In the last fifty years, the inflow of water to the lake decreased by 48%. Somayeh Shadkam and Fulco Ludwig calculated that 60% of this reduction is caused by aspects of climate change such as changes in precipitation and temperature, and that the other 40% is accounted for by the withdrawal of river water for irrigation of surrounding fields. “In order to save the lake, local water management needs to be improved, but climate change also needs to be addressed at an international level,” explains project leader Somayeh Shadkam, a PhD candidate working at Wageningen University & Research and at the International Institute for Applied Systems Analysis (IIASA).

Up until now, the cause for the desiccation of the lake was mainly ascribed to human activity in and around the lake. This new study clearly shows that climate change also plays a significant role in this process. “This means that simply reducing water use alone is insufficient to save the lake,” states Fulco Ludwig. “Climate change needs to be addressed as well. Climate change has a significant impact on water availability all across the world. Studies such as this one highlight the social problems in a scientific manner which enables policy makers to make informed decisions for sustainable water supply now and in the future.”

Click here to read ‘Impacts of climate change and water resources development on the declining inflow into Iran’s Urmia Lake’ by Somayeh Shadkam, Fulco Ludwig, Pieter van Oel, Çağla Kirmit and Pavel Kabat.