Silted up Lake Urmia: a symbol of the water and climate crisis

Photo: Lauren Dauphin / NASA Earth Observatory

In ancient times, Lake Urmia was a mighty body of water. The ancient Assyrians enjoyed its abundance of fish, and oak and juniper trees provided shade on the banks. But as more and more people began to tamper with the lake's resources, the idyll went downhill. These days, the trees have long since been cut down, the lake about as salty as the Dead Sea; a few crabs can survive in it. And the water continues to dwindle, one of the once largest salt lakes on earth is fighting for its existence.

In the mid-4800s, it was still about <> square kilometres in size – Lake Constance, the largest lake in Germany, would have fit nine times over. Currently, the lake, located in the far northwest of Iran, has almost dried up and largely atrophied into a huge, dry salt desert. Bright salt crusts pile up on its shores, boats lie on the bottom far away from water.

Satellite images from Nasa clearly show the decline: the image on the left is from September 2020. It was taken with the Earth observation satellite "Landsat 8" when most of the lake was filled with water. At that time, Lake Urmia benefited from a period of above-average precipitation, which washed a freshwater flood into the lake and caused the amount of water to swell for a short time.

A drop in the ocean

But that was literally just a drop in the ocean, because just three years later, the water level has dropped drastically, as the current image from September of this year shows.

The lake has often experienced such a yo-yo effect. In the mid-90s, for example, the water level reached an interim peak, and in the following two decades the water level fell by more than seven metres. Lake Urmia lost about <> percent of its area. The reasons why these ups and downs occur are complex.

According to current knowledge, several factors contribute to this. On the one hand, there are natural climatic changes. Even in ancient times, it was observed how there was no precipitation and how the regional climate changed in the meantime. On the other hand, humans work by helping themselves directly to the lake, reshaping the environment and also bringing more and more greenhouse gases into the atmosphere with their behavior.

Man-made climate change is very likely partly responsible for several droughts plaguing the region. The lack of water is taking a heavy toll on the soil, which is already scarce in water. Large parts of Iran's land area are considered extremely dry, with an average of less than 250 millimetres of rain falling per year.

In addition, farmers use too much water for agriculture in the region. Farmers who planted their fields around the lake drilled legal, but also many illegal wells to irrigate their fields. This poor water management has an impact on the water table. In addition, less water flowed into the lake because the rivers that feed it were dammed to generate electricity.

Up to 6.5 million residents affected

The decline of the lake is emblematic of the water crisis in Iran and the consequences of the climate crisis. Researchers at the University of Augsburg speak of an environmental disaster that leads to the degradation of soils and freshwater resources, also because the salt from the dry lake is blown onto the fields by the wind and harms the plants, for example.

Of course, all this also has consequences for the people who live around the lake. Depending on the estimate, up to 6.5 million residents are affected, and many may have to leave the region if the situation does not change. Studies have even shown that the devastation of the lake has an impact on the respiratory tract, because dust kicked up from the dry lake bed deteriorates the air quality.

Politicians have taken up the issue years ago, but so far with little success. In any case, many scientists fear that the lake can no longer be saved. In the long term, NASA's satellites may only take pictures of a salt desert.

Joe