3 Water Resource Availability and Quality …
45
and high evaporation increases reliance on groundwater resources. However, groundwater resources will be diminished to satisfy agricultural water demand. Salinization of irrigation water, estuaries, and freshwater systems, and seawater intrusion in
coastal aquifers, could threaten the sustainability of urban and agricultural activity
due to the substantial reduction of freshwater availability. Shallow aquifers are
substantially affected by salinity, leading to agricultural soil salinization and loss
of fertility, which will reduce the amount of land that is suitable for cultivation, and
loss of land in the long term. In Algeria, the salinity of surface waters can reach
up to 1.5 g/L, but in general is around 1 g/L. Groundwater is generally non-saline
worldwide, but it can reach up to 8 g/L. In Tunisia, around 60% of water resources
are located in the North, of which about 70% has salinity below 1.5 g/L. More than
80% of groundwater has salinity exceeding 1.5 g/L, with 30% of the shallow aquifers
with salinity higher than 4 g/L. Groundwater, especially the aquifers located in the
Southern part of the country, has shown an excess of sulfates and chlorides due
to rock weathering (MARHP 2017). Water resources in the South of the country
are composed mainly of three deep transboundary aquifers. The terminal complex
aquifer is depleting from intensive exploitation of groundwater; salinity varies from
1.5 g/L in Nefzaoua to 4 g/L on the peninsula of Kebili. The intercalary continental
aquifer has salinity that varies from 2.5 to 3 g/L at the Chott Fedjej to 5 g/L at El
Borma, while the Djeffara aquifer has salinity between 3 and 8 g/L (CEDARE 2014).
Therefore, salinity represents the main hurdle to a number of economic activities and
even to the supply of potable water. Climate change is forecast to affect the quality of
these resources, especially in the South. This has led the government to build desalination treatment plants to assure sufficient water supply (CEDARE 2014; MARHP
2017).
Apart from salinity, there are multiple water quality parameters that are monitored on a regular basis. The largest surface water area in the North African region
is the Nile River in Egypt. It used to be a freshwater river, with less than 0.5 mg/L
of salinity (Elnazer et al. 2018). Now, it is under great anthropogenic pressure. The
major sources of water pollution to the Nile are the discharge of untreated or partially
treated wastewater, including industrial and domestic effluents, and the release of
drainage water from agriculture, leaching pesticides and nutrients. Water quality
degradation has become of serious concern. Many factors contribute to this pollutant
load, including flow, population density associated with the low rate of connection to
sanitation systems (illegal construction with leaking pipes), industrial activity, and
social and economic conditions. Microbiological pollutants are frequently detected
in some drains and discharge into the Nile as raw effluents that usually find their
way into agricultural drains (Dahshan et al. 2016; Abdel-Satar et al. 2017). Several
studies highlight the variability of water quality of the Nile River. Relatively good
water quality is found in the upstream part at Dakahlia Governorate, while in the
Damietta Governorate, various sources of pollution are observed, including domestic
wastewater, industrial discharge, agricultural runoff, and drainage water (Badr et al.
2016). In Alexandria and Behiera governorates, Mahmoudia canal receives water
from the Rosetta branch, which in turn receives domestic and agricultural waste
from the Zarcon Drain and other non-point sources. In that area, the situation has
45
and high evaporation increases reliance on groundwater resources. However, groundwater resources will be diminished to satisfy agricultural water demand. Salinization of irrigation water, estuaries, and freshwater systems, and seawater intrusion in
coastal aquifers, could threaten the sustainability of urban and agricultural activity
due to the substantial reduction of freshwater availability. Shallow aquifers are
substantially affected by salinity, leading to agricultural soil salinization and loss
of fertility, which will reduce the amount of land that is suitable for cultivation, and
loss of land in the long term. In Algeria, the salinity of surface waters can reach
up to 1.5 g/L, but in general is around 1 g/L. Groundwater is generally non-saline
worldwide, but it can reach up to 8 g/L. In Tunisia, around 60% of water resources
are located in the North, of which about 70% has salinity below 1.5 g/L. More than
80% of groundwater has salinity exceeding 1.5 g/L, with 30% of the shallow aquifers
with salinity higher than 4 g/L. Groundwater, especially the aquifers located in the
Southern part of the country, has shown an excess of sulfates and chlorides due
to rock weathering (MARHP 2017). Water resources in the South of the country
are composed mainly of three deep transboundary aquifers. The terminal complex
aquifer is depleting from intensive exploitation of groundwater; salinity varies from
1.5 g/L in Nefzaoua to 4 g/L on the peninsula of Kebili. The intercalary continental
aquifer has salinity that varies from 2.5 to 3 g/L at the Chott Fedjej to 5 g/L at El
Borma, while the Djeffara aquifer has salinity between 3 and 8 g/L (CEDARE 2014).
Therefore, salinity represents the main hurdle to a number of economic activities and
even to the supply of potable water. Climate change is forecast to affect the quality of
these resources, especially in the South. This has led the government to build desalination treatment plants to assure sufficient water supply (CEDARE 2014; MARHP
2017).
Apart from salinity, there are multiple water quality parameters that are monitored on a regular basis. The largest surface water area in the North African region
is the Nile River in Egypt. It used to be a freshwater river, with less than 0.5 mg/L
of salinity (Elnazer et al. 2018). Now, it is under great anthropogenic pressure. The
major sources of water pollution to the Nile are the discharge of untreated or partially
treated wastewater, including industrial and domestic effluents, and the release of
drainage water from agriculture, leaching pesticides and nutrients. Water quality
degradation has become of serious concern. Many factors contribute to this pollutant
load, including flow, population density associated with the low rate of connection to
sanitation systems (illegal construction with leaking pipes), industrial activity, and
social and economic conditions. Microbiological pollutants are frequently detected
in some drains and discharge into the Nile as raw effluents that usually find their
way into agricultural drains (Dahshan et al. 2016; Abdel-Satar et al. 2017). Several
studies highlight the variability of water quality of the Nile River. Relatively good
water quality is found in the upstream part at Dakahlia Governorate, while in the
Damietta Governorate, various sources of pollution are observed, including domestic
wastewater, industrial discharge, agricultural runoff, and drainage water (Badr et al.
2016). In Alexandria and Behiera governorates, Mahmoudia canal receives water
from the Rosetta branch, which in turn receives domestic and agricultural waste
from the Zarcon Drain and other non-point sources. In that area, the situation has