Measuring and Interpreting Multilayer Aquifer‐System Compactions for a Sustainable Groundwater‐System Development

Ever decreasing water resources and climate change have driven the increasing use of groundwater causing land subsidence in many countries. Geodetic sensors such as InSAR, GPS leveling can detect surface deformation but cannot measure subsurface deformation. A single-well, single-depth extensometer be used to deformation, it delineate depths major compaction provide insight about mechanism throughout a complex aquifer system, unless man extensometers at different are used. We present multilayer well (MLCW), installed borehole, that uses magnetic rings stratum 25 deep 300 m below surface. Our laboratory field assessments indicate 1 mm precision accuracy for one reading. tested performance MLCW by measuring aquifer-system over proximal, middle, distal fans Choushui River Alluvial Fan (CRAF) has long experienced severe subsidence. The measurements were create time-depth diagrams compaction, showing rates layers aquifers aquitards identify compactions. elastic (reversible) inelastic (irreversible) compactions from stress-strain analyses estimate skeletal specific storages safe levels, which extractions caused irreversible hydrogeological parameters derived help governmental agencies determine effective land-use water-use policies, ascertain best strategy utilizing artificial recharge prevent achieve sustainable management.