An Illustration of the Possibility of Using GNSS Observations to Measure Evaporation over a Reservoir Using the Example of Nizhnekamsk HPP

Daily variations of integrated water vapor content in the atmosphere in the region of the Nizhnekamsk HPP were examined, from measurement data of GNSS radio signals in autumn 2010. It was established that the difference of these variations between the remote station and the stations at the buildings of the HPP were caused by evaporation from the surface of the water reservoir, and has an expressed daily variation with a maximum at 12:00 UTC and a range approximately the variation of 0.4 kg/m2.