Division of Energy Systems Analysis – Royal Institute of

An overview of the preliminary intersectoral issues

in the NWSAS

Algiers – 18 July 2017

Youssef Almulla Division of Energy Systems Analysis – Royal Institute of Technology (KTH)

Stockholm - Sweden

Objective of this session is

To develop a common understanding and identification of the key intersectoral issues in the North Western Sahara Aquifer System

(NWSAS).

Introduction

Algeria Tunisia Libya

Country area (km2) 2,381,741 163,610 1,759,540

Country area in the basin (km2) 700,000 80,000 250,000

Share of national territory in the NWSAS (%) 29 49 14

Share of NWSAS (%) 68 8 24

NWSAS:1) The Continental Intercalary (CI):a surface area of 1000,000 km²depth 1500 – 2800 m 2) The Terminal Complex (TC): area of 600,000 km² depth of 100 – 600 m

Algeria57%

Libya22%

Tunisia21%

Population in the NWSAS (2014)

Key intersectoral issues

1) Heavy exploitation of the NWSAS

• The water reserves in theNWSAS: 40,000 billion m3 / year.

• The groundwater recharge isestimated to be 1 billionm3/year.

• The use of the NWSAS increasedsignificantly:

• 1 billion m3/year in 1980s;• to reach about 2.7 - 2.8 billion

m3/year in 2012.

2) Heavy exploitation of the NWSAS

• This heavy exploitation has caused stress on the water resources and increased the risk of: Reduced piezometric head;Loss of artesian pressure;Lower water table; Excessive pumping heights (energy

demand);Others…

1.41

0

0.32

2

0.26

0.52

0

0.5

1

1.5

2

2.5

Algeria Libya Tunisia

Groundwater withdrawals in the NWSAS (BCM)

Non-renewable groundwater withdrawal

Total ground water withdrawal

2) Modern technologies increased the drilling of wells significantly

Location of water points and abstraction in the NWSAS

1950 2012

3) Water and soil salinization due to high use

Surface area (km2)

1,000,000

Theoretical reserve (BCM)

40,000

Theoretical recharge (BCM)

1

Terminal complex (TC)

Intercalary Continental (IC)

Recharge (MCM) 600 400

Average Thickness (m)

300 50 - 100

Salinity (g/l) 2 to 5 1 to 4.5

• Irrigation is responsible for significant amount ofsoluble salt estimated to about 1.2 – 4.4 million tonper year and average of 2 g/l.

• Salinization can also lead to considerable loss ofresources in the ground, estimated at: 4,300 ha per year in Algeria, 300 ha per year in Tunisia.

• The increase in water salinity and soil degradationcauses decline in agriculture yield and farmersrevenues.

4) Increased risk of saline intrusion form chotts

• In steady state: water flows from the aquifer and accumulate in the Chott.

• In unsteady state: inverse flow from the chott (high salinity) to the aquifer occurs.

• Salinization of water in the aquifer will accordingly lead to soil salinization,

• which in turn will impact the ecosystem in the NWSAS.

5) Degradation of the ecosystem and biodiversity • The NWSAS aquifer domain includes many groundwater

dependent ecosystems such as: Sebkhas, national parks, wadies,springs etc.

• The NWSAS domain also includes 7 RAMSAR accredited wetlands.

• The degradation of the water resources in the aquifer affectedseverely the ecosystem and biodiversity.

• Desertification is another environmental threat in the NWSASarea which in some cases can cause irreversible damages.

6) Irrigation water losses

• Average efficiency of irrigation system = 42.4% in the region and can go up to60% at best in some parts of the region.

• In term of volume, the estimated losses of water reach about 2500 m3/ha.

72%

26%

2%Irrigation techniques in the NWSAS

Surface Sprinkling Other

7) Water demand for Concentrated Solar Power (CSP) Plants

• Renewable Energy targets by 2030 (in electricity generation):

• Algeria 27%• Tunisia 30%

• CSP targets by 2030: • Algeria 2000MW.• Tunisia 460MW.


SunSun light (Solar irradiation)Sun light (Solar irradiation)

Electricity Electricity

Steam (High T & P)

Solar photovoltaic (PV) Concentrated Solar Power (CSP)

Turbine

Water consumption for different CSP power generation technologies and different cooling

technologies (Liters/MWh):


Cooling Technology

CSP Technology

Cooling Tower

Dry Cooling

Hybrid Cooling

Trough 3,274 295 1,279

Power Tower 2,975 98 644

Fresnel 3,785 NA NA

Source: National Renewable Energy LaboratoryThe four main Concentrated Solar Power (CSP) technologies

(IEA)

• TuNur solar project in Rjim Maatouq, Tunisia (within the NWSAS).

• Solar Tower plant with molten salt storage

• Phase 1: Capacity: 250 MW Generation 1000 GWh Transmitted to EU through Malta.

• Phase 2: Capacity: 2250 MWGeneration: 9000 GWh Transmitted to EU through Rome.


8) Desalination of brackish water

• In Algeria 12 brackish water desalination plants are operational in theNWSAS.

• IN Tunisia more than 10 brackish water desalination plants are to beinstalled, of which most are to be located within or close to the borderof the NWSAS.

• The desalination technology will be either Reverse Osmosis (RO) orReverse Electro Dialysis (RED).

• Average electricity consumption by brackish water RO plants is in therange of 0.5-2.5 kWh/m3

An overview of the preliminary intersectoral issues

in the NWSAS

Algiers – 18 July 2017

Youssef Almulla Division of Energy Systems Analysis – Royal Institute of Technology (KTH)

Stockholm - Sweden

Water

How does the Energy

sector affect the

Water sector?

What impacts has the Water sector on

the Energy sector?

Energy

Energy

Increased pumping demand:• This heavy exploitation has caused stress on the

water resources and increased the risk of: • Reduced piezometric head;• Loss of artesian pressure;• Excessive pumping heights.

• In order to overcome this obstacle, people tend to dig deeper wells, which means higher pumping head and higher energy bill for pumping.

• Also the use of inefficient pumping systems increased energy losses.

Brackish water desalination:• In Algeria 12 desalination plans are operational in the

NWSAS. IN Tunisia, as part of the National Program forWater Quality Improvement, more than 10 brackishwater desalination plants are to be installed in Tunisia,of which most are to be located within or close to theborder of the NWSAS.

• The desalination technology for the new plants will beeither Reverse Osmosis (RO) or Reverse Electro Dialysis(RED). Average electricity consumption by brackishwater RO plants is in the range of 0.5-2.5 kWh/m3

Water for Solar power plants:

• A CSP plant requires water as the working fluid (forthe steam cycle), as well as for cooling if a coolingtower is used.

• Water consumption can range from 98-295 m3/MWhfor a dry type of cooling, to 2,975-3,785 m3/MWh forthe tower type.

• Several projects are being developed in the region.

Aretsian water :• The pressure of artesian borholes can be

used to produce energy (turbines)• Research and pilot projects are

experimented in Algeria

Access to energy increases water extraction andtransfers:

• The availability of the modern drillingtechnologies and increasing water demandcaused significantly increase in the number ofwells in the NWSAS.

• The number of wells jumped from few wells inthe 1960s to about 18000 wells in 2012.

Water for Enhanced Oil Recovery (EOR)systems :

• Water is injected into the oil fields toincrease pressure and increase oil recoveryfrom existing reservoir.

• Many fields in the region uses thistechnology; i.e Haoud Berkoui which has acapacity of about 190 000 (bbl/d) and waterinjection capacity of 18000 m3/d.

Water

How does the Land/

Agriculture affect the

Water sector?

What impacts has the Water sector on the Land/

Agriculture ?

Land / Agriculture

Land / Agriculture

Soil salinization due to low water quality and inappropriate irrigationtechniques :• The salinization of irrigation water is increasing in the region deteriorating

land quality.• The estimate of soil resources loss reached the level of 4,300 ha per year

over an area of 170,000 ha in Algeria, and 300 ha per year over an area of40,000 ha in Tunisia.

• The population in the NWSAS region is highly dependent on agriculture, theincrease in water salinity and soil degradation causes decline in agricultureyield and farmers revenues.

• Inefficient / Lack of drainage networks causes soils salinization and landsdegradation.

High water waste due to inefficient irrigation systems:• Irrigation of agricultural land in the NWSAS is a main source of wasting

water due to in efficient irrigation systems.• According to (OSS, 2012): the total irrigated area in the NWSAS aquifer is

about 270,000 ha (202,000 ha in Algerian part- 30,000 ha in the Libyan partand 38,000 ha in the Tunisian part). And it is expected to grow to 40,000 haby 2020.

• The average efficiency of irrigation system in the region is 42.4% and can goup to 60% at best in some parts of the region.

• In term of volume, the estimated losses reach about 2500 m3/ha.

Degradation of water resources due to heavy exploitation:• The groundwater recharge is estimated to be 1.4 billion m3/year, however

the use of the NWSAS increased significantly from 1 billion m3/year in 1980to reach about 2.7 - 2.8 billion m3/year in 2012.

• The water use sharing is as follows: Algeria with 2 Billion , Tunisia : 0.3 billionin Tunisia, and Libya 0.5 billion m3/year. The respective sharing of Surface isAlgeria : 700 000 Km², Tunisia : 80 000 km² and Libya 220 000 km².

• This heavy exploitation ,which comes from agricultural activities mainly, hascaused stress on the water resources and increased the risk of drying up ofoutlets and depletion of natural springs as a results of lowering water tables.

Low water quality impacts agriculture production:• Decrease of the yields due to the water quality• Abandonment of certain crops

Water

How do the Ecosystems

and biodiversity

affect the Water

sector?

What impacts has the Water

sector on the Ecosystems

and biodiversity

Ecosystems and Biodiversity


Degradation of the biodiversity due to aquifer overexploitation:

• The overexploitation led to the degradation of water resources inthe aquifer which accordingly affected severely the ecosystem andbiodiversity.

• The NWSAS aquifer domain includes 19 groundwater dependentecosystems (of which 11 are in Tunisia) and 7 RAMSAR accreditedwetlands. These ecosystems include Sebkhas, national parks,wadies, springs etc.

Extreme phenomena

• It is expected that extreme climatic events such as droughts, heatwaves and sirocco could increase both frequency and intensity in thecoming years.

• Such extreme events will have serious consequences for waterresources thus increase the risks on different water uses in the region(i.e drinking water and irrigation water).

New irrigated perimeters

The creation of new irrigated perimeters and modern oases lead toincrease of water demand compared to the traditional oasesecosystems.


How does the Land

Use affect the

Ecosystem Services?

What impacts have the

Ecosystems and

biodiversity on the Land

Use?

Land / Agriculture

Land / Agriculture

Desertification• Is an environmental threat in the NWSAS area which in some cases

can cause irreversible damages.• Among others, the change in land use and vegetation cover is

considered the main reason for desertification in the NWSAS.• This phenomenon has several impacts on the biophysical,

biogeochemical processes and the hydrological cycle of the aquiferarea. Which area accordingly causing loss in habitat, alteration ofecosystem, reducing plant cover and carbon in the soil.

• Land silting reduces the space for socio-economic activties

• Extreme climate phenomena (i.edroughts) will have negativeconsequence on agriculture.

• Degradation of natural spring reducesthe Fresh water available water forirrigation.

References:

• 9 50 in the morning

5) Lack of Water reuse and drainage

• Algeria has plans for 14 Wastewater treatment plants with total capacity of more than 380,000 m3/ day. Distributed as follows:

# Type Number of units

Capacity (m3/day)

1 Urban 101 862,974

2 Rural 7 991

3 Industrial 2 5,270

• Tunisia has 110 sewagetreatment plants operational in2012, with total capacity ofabout 870,000 m3/ day

• Distributed as follows:# Location Capacity (m3/day)

1 Ghardaya 46,000

2 El Oued 76,800

3 Biskra 175,200

4 Ouargla 86,324

Background about the NWSAS

Documents

Division of Energy Systems Analysis – Royal Institute of