[enviro-vlc] UNESCO publishes first world map of underground transboundary aquifers

[Vern Weitzel]

http://portal.unesco.org/en/ev.php-URL_ID=43767&URL_DO=DO_TOPIC&URL_SECTION=201.html

UNESCO publishes first world map of underground transboundary aquifers

UNESCO is publishing the first-ever world map of shared aquifers to coincide 
with the submission to the General Assembly of the United Nations on 27 October 
of a draft Convention on Transboundary Aquifers. Almost 96% of the planet’s 
freshwater resources are to be found in underground aquifers, most of which 
straddle national boundaries.

Despite its strategic importance, no global inventory of this resource had been 
compiled to date. Since 2000, UNESCO’s International Hydrological Programme 
(IHP) has been participating in the establishment of a groundwater database. It 
is now presenting a detailed map of transboundary aquifers – available online – 
showing the delineations of aquifers that are shared by at least two countries. 
It also provides information about the quality of their water and rate of 
replenishment. So far, the inventory comprises 273 shared aquifers: 68 are on 
the American continent, 38 in Africa, 65 in eastern Europe, 90 in western Europe 
and 12 in Asia.

The aquifers, which contain 100 times the volume of fresh water that is to be 
found on the Earth’s surface, already supply a sizeable proportion of our needs. 
The growth in the demand for water since the second half of the 20th century has 
been met by the increased use of underground resources. Globally, 65% of this 
utilization is devoted to irrigation, 25% to the supply of drinking water and 
10% to industry.

Underground aquifers account for more than 70% of the water used in the European 
Union, and are often one of the only – if not the only – source of supply in 
arid and semi-arid zones (100% in Saudi Arabia and Malta, 95% in Tunisia and 75% 
in Morocco). Irrigation systems in many countries depend very largely on 
groundwater resources (90% in the Libyan Arab Jamahiriya, 89% in India, 84% in 
South Africa and 80% in Spain).

Although aquifer systems exist in all continents, not all of them are renewable. 
For example, those in north Africa and the Arabian peninsula were formed more 
than 10,000 years ago when the climate was more humid and are no longer 
replenished. In some regions, even if the aquifers are renewable – being fed on 
a regular basis by rainfall – they are in some cases endangered by 
over-exploitation or pollution. In the small islands and coastal zones of the 
Mediterranean, populations often use groundwater more rapidly than it is 
replenished.

The aquifers in Africa, however, which are some of the biggest in the world, are 
still largely under-exploited. They have considerable potential, provided that 
their resources are managed on a sustainable basis. Since they generally extend 
across several State boundaries, their exploitation presupposes agreed 
management mechanisms in order, for example, to prevent pollution or 
over-exploitation by particular States.

Mechanisms of this kind have begun to emerge in recent years. For example, in 
the 1990s Chad, Egypt, the Libyan Arab Jamahiriya and Sudan established a joint 
authority to manage the Nubian aquifer system in a concerted manner. In their 
project concerning the Iullemeden aquifer, Niger, Nigeria and Mali approved in 
principle a consultative mechanism for administering the aquifer system. But 
such mechanisms are the exception.

The draft Convention on transboundary aquifers, prepared by the United Nations 
International Law Commission with the assistance of experts from UNESCO’s 
International Hydrological Programme (IHP), is therefore intended to fill a gap 
in the law. The text to be submitted to the General Assembly of the United 
Nations on 27 October, calls on aquifer States not to harm existing aquifers, to 
cooperate and to prevent and control their pollution.

The World-wide Hydrological Mapping and Assessment Programme (WHYMAP) was 
launched in 1999* to improve knowledge and management of the Earth’s resources, 
particularly groundwater. In 2000 the IHP launched the Internationally Shared 
Aquifer Resources Management (ISARM) project to compile an inventory and to 
evaluate the world’s transboundary aquifer systems (delineating them, estimating 
their volume, their replenishment rates, etc.). A region-by-region evaluation 
has been launched. In its initial phase it will identify geographical locations 
and then itemize the legal systems of each country as they relate to aquifer 
management.

* By UNESCO with the assistance of the Commission for the Geological Map of the 
World (CGMW), the International Association of Hydrogeologists (IAH), the 
International Atomic Energy Agency (IAEA) and the German Federal Institute for 
Geosciences and Natural Resources (BGR).

Author(s):Press Release N°2008-108
Source:UNESCOPRESS
22-10-2008