Abstract
Groundwater is in a part of global water cycle between the atmosphere and the ocean. Information of global studies on groundwater helps us to understand global environmental issues. Studies on changes in groundwater storage in global basis, responses of groundwater to climate and land cover changes, estimations of paleoenvironments from groundwater, direct (submarine) groundwater discharge into the ocean, responses of groundwater flow system to sea-level changes, are needed to understand the global groundwater hydrology.
