Technologies

Diversion construction with gates and distribution channels [Yemen]

الحواجز (الرزم) والبوابات والسواقي

technologies_1562 - Yemen

Completeness: 82%

1. معلومات عامة

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

Key resource person(s)

SLM specialist:
SLM specialist:

AL Hadrami Yahya

General Directorate of Irrigation

Yemen

SLM specialist:

Sallam Ahmed

Agricultural Research and Extension Authority

Yemen

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Agricultural Research and Extension Authority (AREA) - Yemen
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
General Directorate of Irrigation - Yemen

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:

نعم

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

The stone existed in the region are used for building diversion constructions to raise the level of wadi bed to the level of the inlet of the cultivated land that need to be irrigated from water harvesting in addition to distribution channels in the fields

2.2 Detailed description of the Technology

Description:

Diversion construction (DC) technology is one the structural solutions using stones with slope and tan 30 to slow the water flow and to deposits the carried materials with water to allow water to pass throw the inlet (gate) to the fields that need to be irrigated without damaged mainly vines and qat crops. The site of DC must be built in direction of water flow to direct it to pass to the fields need to be irrigated to get a benefit from this water harvested the height of the DC should be equalled to the height of the cultivated land which ranges between 2-4 meter and the width is 1.5 meter and the length is ranged between 40-60 meter based on the width of wadi bed. The DC should not built totally in one time but should be gradually and by the time as a result of deposit be come at the same level of fields need to irrigated. Finally when the height of DC become equally to level of the field need to irrigated the gate should be determined according to water requirement of cultivated crops. After that distribution channels should built at 1-2 wide, 0.5- 0.8 height and 10-100 length. Such as this type of technology is considered a long term process in the past due to lack of equipments and implements. However now it can be done in short time if all requirement provided especially funds and equipments.

2.3 Photos of the Technology

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

بلد:

Yemen

Region/ State/ Province:

Sana

Further specification of location:

Bani Hushaish district

Comments:

Total area covered by the SLM Technology is 20.6 km2.

Alrawanah Bani Hushaish, which is located on the eastern side of the capital Sanaa, and is about 16 km away

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)
Comments (type of project, etc.):

It is a very ancient technology but was rehabilitated in 1956 by the community

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation

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

Cropland

Cropland

  • Tree and shrub cropping
Tree and shrub cropping - Specify crops:
  • grapes
  • Qat
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 90

Comments:

Major land use problems (compiler’s opinion): Low productivity due to a lack of water (drought)

Major land use problems (land users’ perception): drought

Future (final) land use (after implementation of SLM Technology): Cropland: Ct: Tree and shrub cropping

3.3 Has land use changed due to the implementation of the Technology?

Cropland

Cropland

  • Tree and shrub cropping
Comments:

Future (final) land use (after implementation of SLM Technology): Cropland: Ct: Tree and shrub cropping

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • rainfed
Comments:

Water supply: Also mixed rainfed - irrigated and post-flooding

3.5 SLM group to which the Technology belongs

  • cross-slope measure
  • water diversion and drainage

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S11: Others
Comments:

Specification of other structural measures: Diversion construction with gates and distribution channels

3.7 Main types of land degradation addressed by the Technology

chemical soil deterioration

chemical soil deterioration

  • Cn: fertility decline and reduced organic matter content (not caused by erosion)
water degradation

water degradation

  • Ha: aridification
Comments:

Secondary types of degradation addressed: Cn: fertility decline and reduced organic matter content

Main causes of degradation: floods, droughts, poverty / wealth (poverty)

Secondary causes of degradation: crop management (annual, perennial, tree/shrub) (up takes of major elements of fertility without subsistent)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • reduce land degradation
  • restore/ rehabilitate severely degraded land
Comments:

Secondary 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):

Barrier cuts waterway with gates and distribution channels

Location: Alrawanah Uzlat. Bani Hushaish district

Technical knowledge required for field staff / advisors: high (Construction process requires skills and experiences)

Technical knowledge required for land users: low (Has sufficient expertise)

Main technical functions: water harvesting / increase water supply, water spreading

Secondary technical functions: increase in nutrient availability (supply, recycling,…), increase of groundwater level / recharge of groundwater, Reduce runoff

Structural measure: Diversion construction
Height of bunds/banks/others (m): 2 - 4
Width of bunds/banks/others (m): 1– 1.5

Structural measure: Gates
Height of bunds/banks/others (m): 0.5 -1
Width of bunds/banks/others (m): 0.7–1.2

Structural measure: Channels
Height of bunds/banks/others (m): 0.5–0.8
Width of bunds/banks/others (m): 1 - 2
Length of bunds/banks/others (m): 10-100

Construction material (stone): The diversion construction and the gates are constructed by stones existing in the region

Slope (which determines the spacing indicated above): 5%

Author:

AL-Galal

4.2 General information regarding the calculation of inputs and costs

Specify currency used for cost calculations:
  • USD
Indicate average wage cost of hired labour per day:

7.00

4.3 Establishment activities

Activity Timing (season)
1. Collecting stones and building barriers with gates Before the rainy season
2. Building channels Before the rainy season

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 Collecting stones and building barriers with gates persons/day/barrier 225,0 7,0 1575,0 100,0
Labour Building channels persons/day/barrier 7,0 7,0 49,0 100,0
Equipment Animal traction barrier 1,0 46,5 46,5 100,0
Equipment Tools barrier 1,0 46,5 46,5 100,0
Equipment Animal traction for channel building barrier 1,0 16,3 16,3 100,0
Total costs for establishment of the Technology 1733,3
Total costs for establishment of the Technology in USD 1733,3
Comments:

Duration of establishment phase: 3 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Repair diversion construction and gates annually after the rainy season
2. Clean channels annually after the rainy season

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 Repair diversion construction and gates persons/day/unit 13,0 7,0 91,0 100,0
Labour Clean channels persons/day/unit 2,0 7,0 14,0 100,0
Total costs for maintenance of the Technology 105,0
Total costs for maintenance of the Technology in USD 105,0
Comments:

Machinery/ tools: big hammers, shovel, soil leveller

Costs were calculated according to the current situation, for the barrier with a gate length of 60 meters and a height of 2 meters, and for the channels with an average length of 50 meters and a width of 1 meter.
With regard to maintenance has been developed a lump sum annually where maintenance was done at the current time using modern equipment and as a result of no collapse charges barriers and accessories in most years has been estimated annual sum for the purpose of maintenance in the event of any damage

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

- Transportation and gradient
- difficult roads
- cutting stones

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
  • semi-arid

Thermal climate class: temperate

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.
Comments and further specifications on topography:

Altitudinal zone: 2400 m a.s.l.

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • medium (loamy, silty)
  • fine/ heavy (clay)
Topsoil organic matter:
  • medium (1-3%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil texture: Flood deposits

Topsoil organic matter: After falling vines leaves and grasses

Soil fertility is low - medium (output of the flood deposits)

Soil drainage / infiltration is medium - good

Soil water storage capacity is medium - high

5.4 Water availability and quality

Ground water table:

> 50 m

Availability of surface water:

poor/ none

Water quality (untreated):

poor drinking water (treatment required)

Comments and further specifications on water quality and quantity:

Ground water table: 400 m

5.5 Biodiversity

Species diversity:
  • low

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • mixed (subsistence/ commercial)
Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • poor
  • average
Individuals or groups:
  • groups/ community
Level of mechanization:
  • manual work
  • animal traction
Gender:
  • men
Indicate other relevant characteristics of the land users:

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

Difference in the involvement of women and men: Women could not do the hard work, therefore, men work on the farm and women do the house works.

Population density: > 500 persons/km2

Annual population growth: 3% - 4%

70% of the land users are average wealthy and own 90% of the land (moderate income).
30% of the land users are poor and own 10% of the land.

Level of mechanization: Also small tractors are used

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)?
  • medium-scale
Comments:

0.45 - 0.9 ha fragmentation of tenure is the cause of the small ownership per household

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

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

There are three types of land ownership owned, Waqf, and a share at 70%, 20%, 10% respectively.

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

crop production

decreased
increased

risk of production failure

increased
decreased

land management

hindered
simplified
Water availability and quality

drinking water availability

decreased
increased

demand for irrigation water

increased
decreased
Income and costs

farm income

decreased
increased

diversity of income sources

decreased
increased

Socio-cultural impacts

food security/ self-sufficiency

reduced
improved

cultural opportunities

reduced
improved

SLM/ land degradation knowledge

reduced
improved

situation of socially and economically disadvantaged groups

worsened
improved

livelihood and human well-being

reduced
improved
Comments/ specify:

As a result of improving income and reducing the work load, the access to education is enhanced

Ecological impacts

Water cycle/ runoff

water quantity

decreased
increased

harvesting/ collection of water

reduced
improved

surface runoff

increased
decreased

groundwater table/ aquifer

lowered
recharge
Soil

soil moisture

decreased
increased

soil loss

increased
decreased
Biodiversity: vegetation, animals

habitat diversity

decreased
increased
Climate and disaster risk reduction

flood impacts

increased
decreased
Other ecological impacts

surface crusting

increased
decreased

6.2 Off-site impacts the Technology has shown

water availability

decreased
increased

downstream flooding

increased
reduced

downstream siltation

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
Hydrological disasters
How does the Technology cope with it?
general (river) flood not well

6.4 Cost-benefit analysis

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

neutral/ balanced

Long-term returns:

positive

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

slightly positive

Long-term returns:

very positive

6.5 Adoption of the Technology

  • > 50%
If available, quantify (no. of households and/ or area covered):

537 households covering 100 percent of the stated area

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 91-100%
Comments:

537 land user families have adopted the Technology without any external material support

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: The technology is applied in the whole region, but the lack of capital is an obstacle for continuing conservation operations

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Harvesting flood waters

How can they be sustained / enhanced? Continue maintenance operations
Reduction of the runoff speed

How can they be sustained / enhanced? Continue maintenance operations or introduce cement materials in the construction process to increase the ability to withstand various conditions
Distribution of water on a regular basis

How can they be sustained / enhanced? Maintenance of channels to ensure sustainability

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?
buried sediment distribution channels lining channels for easy cleaning process
Construction costs and labour requirements are high use modern equipment in the construction and maintenance processes
you need time for implementation Use of modern equipment
Severe floodings can demolish barriers and gates Use of cement materials

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Report of traditional knowledge and customs (sallam, et al, 2008)General Census of Population, Housing and Establishment (Census, 2004). Guide of agricultural climate in Yemen (Al Khorasani, 2005).

Available from where? Costs?

Agricultural Research and Extension Authority, AREACentral Bureau of StatisticsAgricultural Research and Extension Authority, AREA

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