Groundwater Resources of the World - Statistics

Map "Groundwater Resources of the World - Statistics"

Groundwater is found almost everywhere, but varies strongly regarding quantity, quality and recharge. The areal distribution of the various hydrogeological types mapped on the groundwater resources map shows that, as a global average, half of the land surface (47 %) of the continents (excluding the Antarctic) is made up of local and shallow aquifers with minor occurrences of groundwater (in these areas groundwater is limited to the alteration zone of the bedrock that may also contain local productive aquifers).

World-wide distribution of hydrogeological units

Approximately 35 % of the land subsurface 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.

This subdivision varies from continent to continent, as outlined in the following table.

	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