The previous entry concerned desertification, so this entry will focus on the opposite – fields in the desert.
Last year, Zaccaria, the guard of the site that we excavate on Sai Island, told us that he had travelled 270 kilometres out in the desert northwest of Sai to a project where Egyptians were cultivating with water from deep wells. This information is verified through these satellite photos provided by the website Earth Snapshot.
There are, as seen on the Google Earth image below, several hundred circular fields under various stages of cultivation. Each of them have a diametre of between 670 and 770 metres, making this cultivation in the desert a substantial contribution to Egypt’s agricultural production.
Another satellite photo from Earth Snapshot shows the position of the fields in relations to the Nile Valley and Lake Nasser (if you download the photo, you can zoom in on the fields).
Earth Snapshot suggests that these fields are watered from the New Valley Project that pumps up water for irrigation from Lake Nasser at Toshka. However, there are no irrigation channels visible leading to the extensive fields as seen on the ground by Zaccarias and on the photo provided here.
So, the fields must be irrigated with water from the Nubian Sandstone Aquifer System (NSAS), which is the largest ‘fossil’ water system in the world. That the water is fossil means that it is ancient, i.e. from a time when rain was falling in the Sahara. This water resource is thus non-renewable, like the oil and mineral resources of the earth. NSAS covers some two million square kilometers under the modern countries Egypt, Sudan, Libya, and Chad. The amount of water is estimated at 375 000 cu km, which is equivalent to about 500 years of Nile River discharge! NSAS is thus an important resource for the four countries, which all have limited surface water.
NSAS is a shared, non-renewable water resource. Over-extraction of water from the aquifer can lead to falling groundwater tables and affect regions far away from the wells. In order to meet the challenges of managing this valuable water resource, a joint project between the International Atomic Energy Agency (IAEA), United Nations Development Programme (UNDP), Global Environment Facility (GEF), and the four countries have been set up: the Nubian Aquifer Project. The aim is to establish rational and equitable management of the NSAS for sustainable socio-economic development and the protection of biodiversity and land resources in the future.