Stockholm university

Lakes are getting drier in southern Sweden

How does climate change and human activities affect lakes in Sweden? A new study from Stockholm University reveals changes in water levels across 144 lakes in Sweden using satellite data and water level stations.

En sjö med vass i förgrunden
Photo: Saeid Aminjafari

“Imagine turning on your kitchen faucet and expecting an endless supply of water from the country's 100,000 lakes, but finding less water flowing from the tap than usual”, says Saeid Aminjafari who is a PhD student at the Department of Physical Geography. 

While this is just an imaginary scenario, satellite observations suggest distinctive recent changes in the water levels of Sweden's lakes, raising questions about potential implications. From the wet regions of Stockholm to Kiruna and Abisko, lakes seem to be experiencing increases in water levels. This is not necessarily a good thing and can, for example, amplify the risk of floods in the region. On the other hand, dry regions from Stockholm to Skåne appear to observe declines in water levels (although not necessarily less water to your kitchen). 

“While we don’t know for sure if climate change plays a role in these changes, we witness the global climatic paradigm in Swedish lakes, also known as Wet Gets Wetter - Dry Gets Drier”, says Saeid Aminjafari.


Human activity

Energy production and water consumption have led to flow regulation of many lakes in Sweden. In order to understand the consequences of human activity, the researches have studied the changes in water levels in 144 regulated and non-regulated lakes. 

“Satellite data revealed that regulated lakes show larger water level changes compared to non-regulated ones, especially in southern Sweden. This emphasizes the impact of human activities on Sweden's lake systems”, says Saeid Aminjafari.

Despite having so many lakes, Sweden has limited continuous gauged lake water level data. Although satellite observations have emerged as a popular alternative to measure water levels in lakes, it has not been used understand the large-scale changes in Swedish lakes. 

"Water level changes in lakes can be just the tip of the iceberg of changes occurring in the entire Swedish freshwater system. Imagine ongoing groundwater changes and other changes in wetlands which we cannot see or are not monitoring", says Fernando Jaramillo who is researcher at the Department of Physical Geography. “It is also worth noting that Sweden currently monitors at most 1% of all the lakes existing in Sweden.”

“We need to monitor lake water levels continuously. Without this detailed analysis, we might not realize how climate change and human activities are directly or indirectly affecting our daily lives. This research helps shed light on how these factors impact our environment, emphasizing the need for action to protect our everyday water resources, says Saeid Aminjafari. 

The article “Distinctive Patterns of Water Level Change in Swedish Lakes Driven by Climate and Human Regulation” is published 5 March 2024 in Water Resources Research. Read article