Global patterns of groundwater table depth (WTD)

Shallow groundwater affects terrestrial ecosystems by sustaining river base-flow and root-zone soil water in the absence of rain, but little is known about the global patterns of water table depth and where it provides vital support for land ecosystems. We present global observations of water table depth compiled from government archives and literature, and fill in data gaps and infer patterns and processes using a groundwater model forced by modern climate, terrain, and sea level. Patterns in water table depth explain patterns in wetlands at the global scale and vegetation gradients at regional and local scales. Overall, shallow groundwater influences 22 to 32% of global land area, including ~15% as groundwater-fed surface water features and 7 to 17% with the water table or its capillary fringe within plant rooting depths.
The authors,given the continued downloads and applications of our earlier model estimates of the global patterns in groundwater table depth, make available to the readers their recently revised estimates, and suggest that future applications use this new dataset, which is substantially different from the earlier estimates. Please see url written the SOURCE field to download the new dataset and the second url in the URL field pointing to a letter describing the new updates by the authors.