Soil water and stable isotopes in the unsaturated zone profile – field observations and analysis

In this review, we provide research data emphasizing the role of groundwater table and hydrometeorological parameters variation on soil water fluctuations in the unsaturated soil profile. We focused on soil water content, air temperature, precipitation and groundwater table observations. The ThetaProbe Soil Water Sensors basing on changes in the apparent dielectric constant were used for soil volumetric water content measurements. The sensors were installed at the different depths of the unsaturated zone profile under natural atmospheric conditions. The observations lasted more than five years (14 November 2013 – 31 December 2018). Groundwater table data was obtained using Diver data loggers, which continuously recorded water pressure and temperature. For more detailed investigations of water and mass transport at the Maišiagala radioactive waste repository site water, stable isotopes as environmental tracers were used as well.