34
O. Mahjoub et al.
1 mm depth depletion of an equivalent layer of water over the total horizontal extent
of these aquifer systems.
North Africa also has a small aquifer system called Murzuq Basin. This aquifer
is located mainly in the southwest part of Libya, with small parts in Algeria, Chad,
and Niger. It covers an area of 450,000 km
2 and contains an estimated 4,800 km
3 of
exploitable groundwater.
Data on non-renewable water sources in the region are often limited and, in
some cases, ignored, due to the incomplete information provided by national water
authorities. This results in unreliable estimates, especially where these resources are
treated as an unrestricted resource and users behave in an individually competitive
manner. Libya is a remarkable example: the mining extraction consumes 90% of its
groundwater supply.
Mazzoni et al. (2018) have developed a model to quantify and forecast water
deficits and depletion in the main exploitable fossil aquifers in North Africa under
different climatic and socioeconomic scenarios from 2016 to 2050. Their results show
that Egypt and Libya will experience, in the upcoming few decades, severe water
deficits of about 45% and 90% of their current water budget in 2050, respectively,
and may reach a total depletion level in 200–350 years under the currently extraction
rates.
3 International Shared River Basins
This section covers transboundary water resources, including international river and
aquifer basins shared by the countries of the North African region. It explores the
impacts of climate variability through changes in precipitation and temperature of
the Nile, which is considered the main African river basin.
3.1 Assessment of Transboundary River Basins
North Africa has a number of transboundary rivers, lakes, and groundwater systems,
as well as in-country basins that traverse different administrative jurisdictions. The
major shared river basins in the region are the Senegal River Basin; Medjerda River
Basin; Tafna, Oued Ben Naima, Guir, Doura, and Dra basins; and the Nile River
Basin (Fig. 4).
The Nile is the longest river in Africa (6,700 km), shared by eleven countries covering an area of 8.9 km
2 , of which 35% contributes to the Nile Basin,
sustaining life for 20% of Africa’s population (The Nile Basin Initiative (NBI)
2017). The NBI is the coordination platform shared by the Nile riparian countries since 1999. The basin is divided generally into two systems: the Blue Nile
(87% of the basin area), which includes four sub-basins (Blue/Abbay, Atbra/Tekeze,
Sobat/Baro/Akobo, and Main Nile) whose total seasonal runoffs contribute almost
O. Mahjoub et al.
1 mm depth depletion of an equivalent layer of water over the total horizontal extent
of these aquifer systems.
North Africa also has a small aquifer system called Murzuq Basin. This aquifer
is located mainly in the southwest part of Libya, with small parts in Algeria, Chad,
and Niger. It covers an area of 450,000 km
2 and contains an estimated 4,800 km
3 of
exploitable groundwater.
Data on non-renewable water sources in the region are often limited and, in
some cases, ignored, due to the incomplete information provided by national water
authorities. This results in unreliable estimates, especially where these resources are
treated as an unrestricted resource and users behave in an individually competitive
manner. Libya is a remarkable example: the mining extraction consumes 90% of its
groundwater supply.
Mazzoni et al. (2018) have developed a model to quantify and forecast water
deficits and depletion in the main exploitable fossil aquifers in North Africa under
different climatic and socioeconomic scenarios from 2016 to 2050. Their results show
that Egypt and Libya will experience, in the upcoming few decades, severe water
deficits of about 45% and 90% of their current water budget in 2050, respectively,
and may reach a total depletion level in 200–350 years under the currently extraction
rates.
3 International Shared River Basins
This section covers transboundary water resources, including international river and
aquifer basins shared by the countries of the North African region. It explores the
impacts of climate variability through changes in precipitation and temperature of
the Nile, which is considered the main African river basin.
3.1 Assessment of Transboundary River Basins
North Africa has a number of transboundary rivers, lakes, and groundwater systems,
as well as in-country basins that traverse different administrative jurisdictions. The
major shared river basins in the region are the Senegal River Basin; Medjerda River
Basin; Tafna, Oued Ben Naima, Guir, Doura, and Dra basins; and the Nile River
Basin (Fig. 4).
The Nile is the longest river in Africa (6,700 km), shared by eleven countries covering an area of 8.9 km
2 , of which 35% contributes to the Nile Basin,
sustaining life for 20% of Africa’s population (The Nile Basin Initiative (NBI)
2017). The NBI is the coordination platform shared by the Nile riparian countries since 1999. The basin is divided generally into two systems: the Blue Nile
(87% of the basin area), which includes four sub-basins (Blue/Abbay, Atbra/Tekeze,
Sobat/Baro/Akobo, and Main Nile) whose total seasonal runoffs contribute almost