Information geometry and early-warning signals for groundwater drought: diagnosis, not prediction, and implications for sustainable aquifer monitoring

This record provides the analysis code and derived datasets supporting the article "Information geometry and early-warning signals for groundwater drought: diagnosis, not prediction, and implications for sustainable aquifer monitoring" (Groundwater for Sustainable Development). The study tests whether groundwater-level records alone can provide advance warning of drought, using 106 boreholes across Great Britain and complete hydrological years from 1953 to 2025. Three families of indicators are evaluated against explicit null models: information-geometric distances (Hellinger and Fisher–Rao) between successive annual level distributions, critical-slowing-down early-warning signals, and borehole-specific drought onsets derived from the monthly Standardised Groundwater level Index (SGI).