The results and data, published in Geophysical Research Letters, could help improve water resource management and climate modelling, and eventually lead to new insights into a range of geological processes. "This is the first global-scale picture of near-surface permeability, and is based on rock type data that goes much deeper than previous mapping," says Tom Gleeson, a postdoctoral researcher with the Department of Earth and Ocean Sciences.
Using recent results of a new global lithological database (GLIM) from Jens Hartmann and Nils Moosdorf, both KlimaCampus at the University of Hamburg, and researchers from Utrecht University in the Netherlands, Gleeson was able to map permeability across the globe to depths of approximately 100 meters. Typical permeability maps have only dealt with the top one to two meters of soil, and only across smaller areas.
"Climate models generally do not include groundwater or the sediments and rocks below shallow soils," says Gleeson. "Using our permeability data and maps we can now evaluate sustainable groundwater resources as well as the impact of groundwater on past, current and future climate at the global scale."
A better understanding of large scale permeability of rock and sediment is critical for water resource management--groundwater represents approximately 99 per cent of the fresh, unfrozen water on earth. Groundwater feeds surface water bodies and moistens the root zone of terrestrial plants.
The study´s maps include a global map at a resolution of 13,000 kilometers squared, and a much more detailed North American map at a resolution of 75 kilometers squared. The research also improves on previous permeability databases by compiling regional-scale hydrogeological models from a variety of settings instead of relying on permeability data from small areas.
The work was funded by the Natural Sciences and Engineering Research Council of Canada, the German Science Foundation, and Utrecht University.
Geophysical Research Letters
Prof. Dr. Jens Hartmann / Dr. Nils Moosdorf
KlimaCampus, Universität Hamburg
040 / 42838 6686 / 6684
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