The Effectiveness of Water Retention in Canals in the Danube-Tisza Interfluve Region, Hungary

The Danube-Tisza Interfluve (DTI) region, one of the most arid areas in Hungary, is threatened by the ongoing decline in groundwater levels driven by the combined impacts of climate change and human activities, including improper land use, excessive groundwater abstraction, and the existing drainage canal networks. One of the emerging solutions is the application of Natural Water Retention Measures (NWRM) (i.e., surface water retention techniques), which can utilize abandoned channels, oxbow lakes, and canals originally designed for draining the region. These measures intend to enhance the water resilience of different landscapes. While these measures have been used globally, their impacts on the shallow groundwater systems are rarely monitored. This study aims to evaluate the effectiveness of a canal-based water retention measure in Bátya Municipality, located in the southern part of DTI, by assessing the changes in the groundwater level and hydrochemical parameters in the near-surface aquifer. The research integrates electrical resistivity tomography (ERT) surveys, soil analyses, water chemistry analyses, and water level monitoring through wells to characterize the subsurface conditions and investigate the physical and chemical effects of infiltration. The results provide key insights into the infiltration processes related to canal-based water retention and its spatial influence on the groundwater resources in the study area. Furthermore, the study contributes to the understanding of how NWRMs can enhance groundwater recharge to help buffer the anthropogenic and climate change impacts on shallow groundwater systems. This work is funded by the LIFE LOGOS 4 WATERS project of the European Union and carried out in collaboration with the General Directorate of Water Management (GDWM). The study is also supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences.