Temperature patterns and factors governing thermal response in high elevation springs of the Swiss Central Alps

Temperature monitoring in 41 springs in different parts of the Swiss Central Alps revealed individual patterns, which seem to be determined by different factors. Geology plays an important role since karst springs in limestone rock often show temperatures below 3°C during winter. They are paralleled to the formation of ice and/or a strong decrease in discharge. In karst springs with permanent flow, temperature did not differ from springs of other geological formations. The water temperature of springs depends on thermal exchanges with the rock during the recharge process. Therefore, elevation, exposure, and permafrost location in the catchment area are expected to be the key factors governing water temperatures in alpine springs. The temperature showed a significant decrease of 0.37°C per 100 m of elevation. The water in springs facing north and west was significantly colder than in south-exposed springs. The temperature significantly increased with the distance to regions of permafrost in the catchment. Understanding the factors governing the thermal patterns will help predict the implication of climate change on springs.