Monitoring of Thermal Stratification in Lakes with Single Point Temperature Measurement System
The density of water shows fluctuations due to its thermal properties. According to this property of water, in large
and deep lakes especially, while less dense water remains at the top, more dense water sinks to the bottom. This leads to
stratification of the lake. The thermal stratification and also the layer dissolved oxygen levels are thus determined by
temperature. To study stratification, temperature measurements at various depths are conducted. In this study, a simple
measurement system was devised which relies on measurements at a single point, thus making time consuming and costly
schemes unnecessary. An ARDUINO circuit element was utilized and a temperature probe was lowered into the lake (the
Borabey Lake in Eskisehir, Turkey) powered by a DC reduction motor. A CDT type equipment was used to check the
accuracy of measurements. RTRM (Relative Thermal Resistance to Mixing) values were determined based on the
temperature profiles and layer boundaries were found. The equipment used can be set to work replacing costly and
sophisticated methods of determining the stratification, while obtaining reliable measurements.
Index terms - Thermal stratification, single point temperature measurement, RTRM.