Drought-driven Release of Heavy Metals threatens Water Quality (DRYMET)

Water resources such as rivers and springs are under increasing pressure due to warmer and drier summers. The quality of water resources, especially in southern Switzerland, is threatened by the mobilization of heavy metals in forest soils. Previously thought to be immobilized, these heavy metals may be released into runoff or percolation water due to extensive soil drying and drought followed by intense precipitation ("dry-wet cycles"). Understanding how dry-wet cycles affect heavy metal mobility in forest soils is therefore critical to predicting water quality. 

This project will investigate 

• heavy metal (lead, copper and nickel) content and binding mechanisms in forest soils at three sites in Ticino (Gagetto, Chironico, and Novaggio), and 
• dynamics of heavy metal release from soils downslope over dry-wet cycles. 

This project will provide knowledge of risk zones for heavy metal contamination, allowing communities to mitigate this risk and adapt their water use.