Department Surface Waters - Research and Management

Temperature monitoring of Swiss lakes

In this pilot project, Eawag is testing various methods for continuous temperature monitoring in lakes and the evaluation of the observed data in collaboration with the Federal Office for the Environment. Temperature is a key parameter for environmental conditions in a lake. Temperature conditions directly influence the metabolism of all aquatic organisms and determine the rates of chemical and biological processes. Lake temperatures are also a reflection of the mixing processes, which are driven by heat exchange and the wind at the lake surface. The mixing processes lead to an exchange of oxygen and nutrients between different depths and thus determine the living conditions for the organisms in the lake.

Climate change leads to significantly increased temperatures in Swiss lakes. The seasonal dynamics of temperature and vertical mixing are changing, with corresponding consequences for lake ecology. The planned monitoring network of continuous temperature measurements in a representative selection of lakes will enable an accurate monitoring of these changes. The temperature data will also be useful for interpreting observed changes in the biology or chemistry of a lake.

As part of the pilot project, measuring stations will be installed in three larger lakes (Lake Ägeri, Lake Murten and Lake Hallwil) and a number of small lakes. The measurement data from the small lakes will be read out and published twice a year. The stations in the larger lakes will be deployed in the course of 2022 and will include direct data transmission.