The Rappbode Reservoir in the Harz region is Germany’s largest drinking water reservoir, supplying around one million people with drinking water in areas including the Halle region and the southern part of the state of Saxony-Anhalt.
The Rappbode Reservoir in the Harz region is Germany’s largest drinking water reservoir, supplying around one million people with drinking water in areas including the Halle region and the southern part of the state of Saxony-Anhalt. Water temperatures in the reservoir now have the potential to increase significantly due to climate change. If average global warming reaches between 4 and 6 degrees by the year 2100, as the current trend suggests, temperature conditions in the Rappbode Reservoir will become comparable to those in Lake Garda and other lakes south of the Alps. In an article in Science of the Total Environment magazine, a team of researchers led by the Helmholtz Centre for Environmental Research (UFZ) writes that the reservoir’s operators could partially offset the impacts this will have on the drinking water supply - to do so, they would have to change the way the reservoir is managed.
The impacts of climate change can already be seen in the Rappbode Reservoir: Over the past 40 years, the water surface temperature in the reservoir has increased by around 4 degrees in the summer months. This trend could continue, as has now been demonstrated by a team of researchers led by Dr Karsten Rinke, who researches lakes at UFZ. Working on the basis of a lake model developed by US researchers, the team took into account potential reservoir management strategies to forecast the impacts climate change could have on water temperatures and on the lake’s physical structure, which control the stratification and seasonal mixing of the body of water. Their research looked at three scenarios for future greenhouse gas emissions. The so-called "representative concentration pathways" (RCPs) describe whether greenhouse gas emissions will be halted (RCP 2.6), will continue to rise (RCP 6.0) or even continue to increase unabated (RCP 8.5) by 2100. According to the Intergovernmental Panel on Climate Change IPCC, the latter case would result in average global warming of more than 4 degrees by the end of this century.
Read more at Helmholtz Centre for Environmental Research - UFZ
Image: The Rappbode Reservoir in the Harz region is Germany’s largest drinking water reservoir. (Photo Credit: André Künzelmann / UFZ)