Model-based assessment of groundwater recharge in Slovenia

• Published in: Environmental earth sciences Vol. 74; no. 7; pp. 6177 - 6192
• Main Authors: Tetzlaff, Björn, Andjelov, Mišo, Kuhr, Petra, Uhan, Jože, Wendland, Frank
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2015; Springer Nature B.V
• Subjects: base flow; Biogeosciences; drought; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; European Union; Geochemistry; Geology; groundwater; Groundwater recharge; hydrologic data; hydrologic models; Hydrology/Water Resources; laws and regulations; Legislation; managers; Original Article; runoff; seasonal variation; Terrestrial Pollution; water balance; water management; Germany; Slovenia; MED, Slovenia; GROWA; Slovenia; Hydrological modeling; Base flow indices
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-015-4639-5

The implementation process of the EU water legislation (EU WFD, EU GWD) has put pressure on environmental managers to create, analyse and disseminate hydrological data in recent years. In this context, distributed hydrological model results at the macro scale (>10,000 km²) have gained importance for the Environment Agency of the Republic of Slovenia, too. Within a joint project the distributed water balance model GROWA, developed for Germany, has been adapted to Slovenia by re-calibrating the routine for determining the average annual groundwater recharge rate. This routine consists mainly of a base flow index approach (BFI). This BFI is based on 41 different site conditions in Slovenia, whereas lithology dominates the recharge process. This paper outlines the general GROWA approach, the required input data, and the calibration process. Validated model results for the period 1971–2000, especially total runoff and base flow, are presented and discussed. These results have been used already for practical water management issues in Slovenia on European, national and regional level. It is shown that Slovenian groundwater resources exhibit high regional and seasonal variability. Tendencies of more frequent and more pronounced droughts have been detected. As demonstrated by the results GROWA is a valuable tool for the spatially distributed assessment of groundwater recharge in Slovenia.