Global hyper-resolution groundwater dataset for assessing historical and future groundwater dynamics

Barry van Jaarsveld , Niko Wanders , Nicole Gyakowah Otoo, Edwin Sutanudjaja, Jarno Verkaik, Daniel Zamrsky, Marc Bierkens

Sustainable management of global groundwater is a key societal challenge and central to Sustainable Development Goals. To address limited observations and coarse global models, we present a global hyper-resolution dataset of monthly groundwater heads and water table depth at 30 arc-seconds (~1 km), simulated by GLOBGM, a global groundwater flow model. The data set follows ISIMIP protocols and enables comparison of impacts of climate change between sectors and models. Using ISIMIP3a inputs, groundwater dynamics is simulated for a reference period (1960–2019) to support model evaluation and attribution of observed impacts to climate variability and change. Following ISIMIP3b, historical baselines (1960–2014) and three combined socioeconomic–climate scenarios (2015–2100; SSP1-RCP2.6, SSP3-RCP7.0, SSP5-RCP8.5) are simulated with five GCMs, supporting robust detection and impact assessment of future change. Regions of reduced reliability are mapped and quality assurance flags are provided to guide appropriate use and interpretation. The dataset offers comprehensive, high resolution information to assess groundwater dynamics for past and future, supporting improved global water resource management and climate impact assessments.