Technologies

Cistern [Tunisia]

Majen / Majel / fasquia (Ar)

technologies_1413 - Tunisia

Completeness: 67%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:

Sghaier Mongi

Institut des Régions Arides IRA

Tunisia

SLM specialist:

Chniter Mongi

Commissariats Régionaux au Développement Agricole CRDA

Tunisia

SLM specialist:
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Institut des Régions Arides de Médenine (Institut des Régions Arides de Médenine) - Tunisia
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Commissariats Régionaux au Développement Agricole (CRDA) - Tunisia

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Cisterns are reservoirs used for storing rainfall and runoff water for multiple purposes: drinking, animal watering and supplemental irrigation.

2.2 Detailed description of the Technology

Description:

Cisterns were traditionally used to provide drinking water. In the cistern system, runoff water is collected and stored in stone-faced underground cisterns, of various sizes, called majel (private reservoirs) and fesquia (communal reservoirs). Basically, a cistern is a hole dug in the ground and lined with a gypsum or concrete coating, in order to avoid vertical and lateral infiltration. Each unit consists of three main parts: the impluvium, the sediment settlement basin, and the storage reservoir. The impluvium is a sloping piece of land delimited by a diversion channel (hammala).

Purpose of the Technology: It is estimated that a tank with a capacity of 35 m3 can meet the annual water needs of a family and its livestock (Ennabli, 1993).

Establishment / maintenance activities and inputs: In flat areas, where it is possible also to exploit floods via a diversion dyke, one also finds artificially paved runoff areas. A small basin before the entrance of the cistern allows the sedimentation of runoff loads. This improves the stored water quality and reduces maintenance costs. Big cisterns have, in addition to the storage compartment, a pumping reservoir from which water is drawn (Ouessar, 2007).

Natural / human environment: Small private and communal cisterns (5 to 200 m3) and big cisterns (up to 70,000 m3), mainly built during the Roman and Arab-Muslim eras, can be found throughout the water-deficient zone south of the 400-mm isohyet .

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

Country:

Tunisia

Region/ State/ Province:

Medenine

Further specification of location:

Medenine nord

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 10-100 km2

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • more than 50 years ago (traditional)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • as part of a traditional system (> 50 years)

3. Classification of the SLM Technology

3.2 Current land use type(s) where the Technology is applied

Land use mixed within the same land unit:

Yes

Specify mixed land use (crops/ grazing/ trees):
  • Agroforestry

Cropland

Cropland

Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 180Longest growing period from month to month: Oct - Apr

Grazing land

Grazing land

Other

Other

Comments:

Major land use problems (compiler’s opinion): Runoff loss

Major land use problems (land users’ perception): Water loss

3.5 SLM group to which the Technology belongs

  • water harvesting

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S11: Others
Comments:

Main measures: structural measures

3.7 Main types of land degradation addressed by the Technology

water degradation

water degradation

  • Ha: aridification
Comments:

Main type of degradation addressed: Ha: aridification

Main causes of degradation: droughts

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • reduce land degradation
Comments:

Main goals: mitigation / reduction of land degradation

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Components of the cistern system.

south east Tunisia

Date: January 2009

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

Main technical functions: water harvesting / increase water supply

Structural measure: Reservoir
Depth of ditches/pits/dams (m): 4-10
Width of ditches/pits/dams (m): 2-4

Construction material (stone): Stone

Construction material (concrete): coating

For water harvesting: the ratio between the area where the harvested water is applied and the total area from which water is collected is: 1:4

Author:

Ouessar M., Medenine, tunisia

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

TND

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

1.3

Indicate average wage cost of hired labour per day:

10.00

4.3 Establishment activities

Activity Timing (season)
1. Pit digging
2. Coating

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Labour ha 1.0 250.0 250.0
Construction material ha 1.0 150.0 150.0
Total costs for establishment of the Technology 400.0
Total costs for establishment of the Technology in USD 307.69
Comments:

Duration of establishment phase: 1 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Desilting Yearly
2. Repairs Each 3-5 years

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Labour ha 1.0 80.0 80.0
Construction material ha 1.0 50.0 50.0
Total costs for maintenance of the Technology 130.0
Total costs for maintenance of the Technology in USD 100.0

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • arid

Thermal climate class: subtropics

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
Landforms:
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.

5.4 Water availability and quality

Water quality (untreated):

good drinking water

5.6 Characteristics of land users applying the Technology

Off-farm income:
  • > 50% of all income
Relative level of wealth:
  • poor
  • average
Individuals or groups:
  • individual/ household
Gender:
  • men
Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly common / average land users

Population density: 10-50 persons/km2

Annual population growth: 0.5% - 1%

10% of the land users are rich and own 15% of the land.
70% of the land users are average wealthy and own 75% of the land.
20% of the land users are poor and own 10% of the land.

5.7 Average area of land used by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • small-scale

5.8 Land ownership, land use rights, and water use rights

Land ownership:
  • communal/ village
  • individual, titled
Land use rights:
  • communal (organized)
  • individual
Water use rights:
  • communal (organized)
  • individual

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

animal production

decreased
increased
Water availability and quality

drinking water availability

decreased
increased

Socio-cultural impacts

SLM/ land degradation knowledge

reduced
improved

conflict mitigation

worsened
improved
Comments/ specify:

negligible (0-5%)

Improved livelihoods and human well-being

decreased
increased

Ecological impacts

Water cycle/ runoff

water quantity

decreased
increased

harvesting/ collection of water

reduced
improved
Soil

soil cover

reduced
improved

soil loss

increased
decreased
Climate and disaster risk reduction

wind velocity

increased
decreased

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change
Season increase or decrease How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
local windstorm well
Climatological disasters
How does the Technology cope with it?
drought not well
Hydrological disasters
How does the Technology cope with it?
general (river) flood well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period well

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

positive

Long-term returns:

positive

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

positive

Long-term returns:

positive

6.5 Adoption of the Technology

Comments:

30% of land user families have adopted the Technology with external material support

70% of land user families have adopted the Technology without any external material support

There is a moderate trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Availability of water for multiple purposes
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Increased availability of water especially in remote areas

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Creation of degradation hot spots around animal watering points. Multiplication of watering points.

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Ben Mechlia, N., Ouessar, M. 2004. Water harvesting systems in Tunisia. In: Oweis, T., Hachum, A., Bruggeman, A. (eds). Indigenous water harvesting in West Asia and North Africa, , ICARDA, Aleppo, Syria, pp: 21-41.

Available from where? Costs?

IRA, ICARDA

Title, author, year, ISBN:

Chahbani, B. 2004. Technical innovations to optimize water harvesting, conservation and use for a sustainable development of rainfed agriculture in arid zones. Options Méditerranéennes, 60: 73-78.

Available from where? Costs?

IRA, CIHEAM

Title, author, year, ISBN:

El Amami, S. 1984. Les aménagements hydrauliques traditionnels en Tunisie. Centre de Recherche en Génie Rural (CRGR), Tunis, Tunisia. 69 pp.

Available from where? Costs?

IRA, CRGER

Title, author, year, ISBN:

Ennabli, N. 1993. Les aménagements hydrauliques et hydro-agricoles en Tunisie. Imprimerie Officielle de la République Tunisienne, Tunis, 255 pp.

Available from where? Costs?

IRA, INAT

Title, author, year, ISBN:

Ouessar M. 2007. Hydrological impacts of rainwater harvesting in wadi Oum Zessar watershed (Southern Tunisia). Ph.D. thesis, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium, 154 pp.

Available from where? Costs?

IRA

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