02. Water Quality Profiles Liesjärvi

Every year I try to measure a water quality depth profile in the middle of lake Liesjärvi. At every 1 m depth the temperature (degrees Celsius), pH, and conductivity (microSiemens) are measured in the middle of the lake were the lake is about 18.0-18.5 m deep.

Figure 1. Temperature profile in lake Liesjärvi. Spring 2017 (11 days after disappearance of the ice cover) stands out with its
relatively low temperatures. In summer (i.e. all other observations), differences in temperatures in the first two metres depend
on summer weather conditons. At 6 m depth temperature is constant with depth and varies between 8-10 degrees Celsius.

Figure 2. pH profile in lake Liesjärvi. pH decreases with water depth, and it seems as if the pH is higher in spring compared to summer.

Figure 3. EC profile in lake Liesjärvi. Electric conductivity increases with water depth, but this increase is rather small.