On Friday, July 6th 2018, Janja Vrzel successfully defended her doctoral dissertation “Surface-Groundwater Interactions in the Ljubljansko Polje Aquifer System (Slovenia)” at the Jožef Stefan International Postgraduate School in Ljubljana, Slovenia. Janja has been a co-supervised student of Prof. Dr. Nives Ogrinc (Jozef Stefan Institute), Prof. Dr. Ralf Ludwig (Ludwig-Maximilians-Universität München) and Assoc. Prof. Dr. Goran Vižintin (University of Ljubljana) and has been working at the Ludwig-Maximilians-Universität in Munich for the past three years on, among other projects, GLOBAQUA.

Janja’s work involved an investigation of the patterns of nutrients and other hydrological issues affecting groundwater and river water in order to identify stressors and the impact that these have on groundwater and on river water. Her work goes further though, and by treating groundwater and surface water as a single system, she explains the impact that stressors have on groundwater-surface water interactions. She exemplifies this with two case studies, the Sava River Basin and a small aquifer within the basin, the Ljubljansko polje aquifer.

The aquifer is located in central Slovenia and is the primary source of drinking water for the city of Ljubljana and its surrounds. This research took an interdisciplinary approach to understanding groundwater surface water interactions by combining geochemistry, hydrology, statistics, and by modelling percolation of local precipitation and river water and groundwater flow. A combination of the various different tools used in this thesis creates a clearer picture of the water cycle in the study area in space and time, both historically and in the future (year 2036–2065). Her work so far has resulted in seven published papers and is a real success story of the GLOBAQUA project.