Shallow groundwater temperatures are increasing as a consequence of global warming. At the same time, climate models project substantial changes in future groundwater recharge, with impacts on groundwater levels. We investigated the combined effects of these two processes. Our modeling results suggest that decreased annual recharge or increased cold recharge in winter can locally slow groundwater warming, but not sufficiently to stop or reverse the overall warming trend.

The Global Heat Flow Database grew from 58,302 data points in 2012 to 91,182 in 2024, with enhanced quality assessments. Despite this, gaps in data and methodological details persist, especially in underrepresented regions. The database is crucial for geophysical, geothermal, and environmental research, offering valuable insights into Earth's thermal processes.

We develop a simplified model which describes the geological geometry of the Vendenheim site, the solid and fluid properties were adapted from studies in the area. We implement compute the hydrothermal flow with a temperature dependent density and viscosity in a porous medium, in order to verify if a hydrothermal convective system is compatible with known observations at the Vendenheim site, and to get a better idea of the initial conditions of a model for an induced seismicity model. 

Concepts of High-Temperature Aquifer Thermal Energy Storage (HT-ATES) are investigated for system application in the German Molasse Basin. We quantify via physics-based numerical modelling the system performance with respect to HT-ATES concept development and provide a predictive analysis of HT-ATES application in the Upper Jurassic reservoir. Results demonstrate a non-uniform layer-specific distribution of the thermal front propagation, while promising heat recovery efficiencies are predicted.

To operate aquifer thermal energy storages in a sustainable way, we located an artesian aquifer other than the aquifer storage in a research wellbore by analyzing the subsurface temperature as monitored with a fiber optic cable in three artesian flow tests. The positioning of the artesian aquifer was validated via numerical modelling. Analyses of the temperature data and numerical modelling enabled determining the profile of flow velocity, flow rate and the depth interval of inflow.