Statistics (first interpretation from WHYMAP 2008)
World-wide distribution of main hydrogeological units
Approximately 35 % of the land subsurface (excluding the Antarctic) host relatively homogeneous aquifers usually in large sedimentary basins that may offer good conditions for groundwater exploitation.
18 % of the land subsurface comprise aquifers in a geologically complex setting with highly productive aquifers in heterogeneous folded or faulted regions in close vicinity to non-aquifers.
Minor occurrences of groundwater generally in local and shallow aquifers (in these areas groundwater is limited to the alteration zone of the bedrock that locally also may contain productive aquifers) dominate almost half of the land surface (47 %).
| Major groundwater basins | Complex hydrogeological structures | Local and shallow aquifers | ||||
|---|---|---|---|---|---|---|
| (million km²) | (%) | (million km²) | (%) | (million km²) | (%) | |
| Africa | 13.48 | 44.9 | 3.31 | 11.0 | 13.22 | 44.1 |
| Asia | 14.54 | 32.0 | 7.84 | 17.3 | 22.98 | 50.7 |
| Australia, New Zealand | 2.60 | 32.5 | 2.90 | 36.3 | 2.49 | 31.1 |
| Europe | 5.15 | 53.0 | 1.82 | 18.8 | 2.74 | 28.2 |
| Central-/ South-America | 8.35 | 45.0 | 2.02 | 10.9 | 8.18 | 44.1 |
| North-America | 3.21 | 15.0 | 5.75 | 26.9 | 12.40 | 58.1 |
World (excl. Antarctica) | 47.32 | 35.6 | 23.64 | 17.8 | 62.02 | 46.6 |
Detailed distribution by continents of main hydrogeological units are shown on the Map "Groundwater Resources of the World 1 : 25 000 000" (ed. 2008), Statistics (PDF, 6 MB).