Modelling hydrological drought and its recovery given natural and anthropogenic scenarios in South America

Changes in groundwater recharge in areas where irrigated agriculture has increased despite low precipitation and surface water allocation are a big concern. The increasing water demand has raised global drought intensities by 10-500%, worsening hydrological drought. Agriculture accounts for 69% of total groundwater abstraction worldwide, and South America expects to face unprecedented hydrological drought conditions within the next 30 years with uncertain impacts (UNESCO 2022, Wada 2016, Wanders & Wada 2015, Siebert et al. 2015). This study compares coupled and non-coupled versions of PCR-GLOBWB2.0 with MODFLOW regarding model selection and scenario comparison. Natural and human scenarios are presented to understand the effects of groundwater depletion and drought recovery. The scenario comparison evaluation of groundwater fluxes, drought characteristics, and recovery reveals changes in the water cycle due to anthropogenic impacts. This is valuable for identifying drought vulnerability in regions where water management is critical for human consumption and ecosystems.