are variable. These estimates range from approximately 113 to 510 km3 yr-1 and variation in estimates is due to methods and spatio-temporal scales considered . Global hydrological models  show that human-induced groundwater depletion at rates exceeding 20 mm yr-1  is occurring in the major aquifers systems such as the High Plains and California Central Valley aquifers , Arabian aquifer , North-Western Sahara Aquifer System , Indo-Gangetic Basin  and North China Plain  . Groundwater depletion at lower rates  is taking place in the Amazon Basin  and Mekong River Basin , primarily due to climate variability and change . A global-scale analysis
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report