Towards improved global estimates and model representations of water storage in the unsaturated zone

Abstract

The unsaturated zone is a globally important, dynamic water store, which affects water resources, agriculture and pollutant transport. Despite this, the magnitude of unsaturated zone water storage remains highly uncertain. This work provides the first global estimates of the magnitude of this store (1.0 x105 km3) in comparison to recent estimates of global modern groundwater (3.5x105 km3), before presenting a roadmap for improved representation of the unsaturated zone in global hydrological models.