Quantifying subsurface hydro-geomechanical properties using the groundwater response to Earth and atmospheric tides

ended

Groundwater resources underpin ecosystems and human activities, yet their continued global depletion causes problems including deterioration of water quality and ecology due to baseflow reduction, land subsidence and seawater intrusion. Accurate quantification of groundwater flow and storage changes is critical to enable adaptive resource management, for example through assessing potential impacts from over-extraction and determining sustainable yields. This requires detailed knowledge of groundwater systems, such as the spatial distribution and temporal variability of hydro-geomechanical (hydraulic and poroelastic) subsurface properties. Current groundwater investigation methods (such as aquifer testing) require high effort and are costly to conduct, restricting the rate and frequency of testing thus resulting in spatially limited and static outcomes. This project will develop SubTideTools (STT), a novel methodology to quantify hydro-geomechanical subsurface properties and to characterise groundwater systems using the ubiquitous Earth and atmospheric tides embedded in pore pressure measurements. STT will be developed, verified with traditional investigation techniques and released as an open source and access computational toolbox. STT will enable automated calculations of time-variable subsurface properties from existing records of groundwater and atmospheric pressure routinely acquired by global monitoring programs. The project will therefore shift the paradigm about how groundwater data are used and add significant value to existing monitoring programs, enhancing resource management decisions and improving implementation of the EU Water Framework Directive. STT directly addresses the societal challenge ‘Climate Action, Environment, Resource Efficiency and Raw Materials’ in the EU Framework Programme for Research and Innovation (HORIZON2020).