Gravity as a tool to improve the hydrologic mass budget in karstic areas

Abstract

Abstract. Monitoring the water movements in karstic areas is a fundamental but challenging task due to the complexity of the drainage system and the difficulty in deploying a network of observations. Gravimetry offers a valid complement to classical hydrologic measurements in order to characterize such systems in which the recharge process causes temporarily accumulation of large water volumes in the voids of the epi-phreatic system. We show an innovative integration of gravimetric and hydrologic observations that constrains a hydrodynamic model of the Škocjan cave system (Slovenia). We demonstrate how the inclusion of gravity observations improves water mass budget estimates for the Škocjan area based on hydrological observations only. Finally, the detectability of water storage variations in other karstic contexts is discussed with respect to the noise performances of spring and super-conducting gravimeters.

Advancing measurements and representations of subsurface heterogeneity and dynamic processes: towards 4D hydrogeology

“…Time-lapse gravimetry has been used to identify and constrain subsurface water storage changes, e.g. in artificial recharge facilities (Kennedy et al, 2016), to separate precipitation and groundwater mass signals (Delobbe et al, 2019), to locate karst storage dynamics (Pivetta et al, 2021) and identify evapotranspiration patterns (Carrière et al, 2021). Further data acquisition procedures and treatments that enhance sensitivity to local processes (e.g., gravity gradients and hydrological modelling coupled with gravity measurements (Cooke et al, 2020, table 1.C.5) are needed to provide more quantitative interpretations.…”