Technologies

Contour Tied Trench [Afghanistan]

Chuquorak (Dari)

technologies_1661 - Afghanistan

Completeness: 80%

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:
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
HELVETAS (Swiss Intercooperation)

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

03/02/2013

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:

Trenches with soil bunds constructed in a tied manner along contour lines to trap surface runoff and sediments from degraded uplands

2.2 Detailed description of the Technology

Description:

Contour Tied Trenches (CTT) were constructed to trap and retain surface runoff and sediments with the main objective of reducing flash flood risks from the Sou-rakhak watershed which was badly degraded due to overgrazing, excessive cutting of shrubs for fuel wood, rainfed cropping and recurring droughts. The technology was combined with other structural measures like soil bunds, check dams, water ponds, and plantation of fruit, non-fruit trees, fodder crops like alfalfa, Asafoetida and Cumin as cash crops. The watershed is also protected from grazing and shrub cutting by the participating communities. Community bakeries were constructed in the valleys and bio-briquette technology promoted for reducing shrub consump-tion/cutting.

Purpose of the Technology: Continuous Contour Trench (CCT) technology was applied to trap and retain surface runoff and sediments with the main objective of reducing flash flood risks from Sourakhak watershed and preventing damages due to flash floods in the valleys.

Establishment / maintenance activities and inputs: Feasibility studies were conducted and workers from three Community Develop-ment Councils (CDCs) of Roy-e Sang (Kahmard) implemented the construction works based on the technical proposals. The workers were organised by the Sourakhak watershed management committee and they got a daily wage of USD 5 for their labour inputs. About 670 families (276 person days/ha) participated in the construction of CTTs and other technologies.

One supervisor appointed by the communities and a watershed worker from HEL-VETAS Swiss Intercooperation side, both paid by the project, monitored the water-shed works with technical advice from the project staff. The work was carried out in phases and in 4 years (starting 2009) about 65,000 trenches were constructed. About 216 trenches were constructed per hectare and the construction cost was about 1450 USD/ha, which included 1380 USD for labour and 70 USD for tools. The International Swiss Re Award (2009), the Swiss Agency for Development and Cooperation (SDC), HELVETAS Swiss Intercooperation and the participating families financially contributed to the watershed management works.

Natural / human environment: Sourakhak watershed has a semi-arid and temperate climate. The area receives up to 400 mm rainfall (annually) and snow during winter time. The watershed elevation ranges from 2000-3000 m amsl and soil type is sandy-loam to clay type. The land users who applied thsi technology are mostly smallholders. The uplnad areas where the technology was applied is owned by the state, but local communities have long term land use rights.

Sourakhak watershed has a semi-arid and temperate climate. The area receives up to maximum 400 mm rainfall annually in a normal year and snow during winter. About 80% of the rain falls from March to June, with most rain falling in the months of April and May. The watershed is located at an elevation ranging from 2000-3000 m (amsl) and the soil is sandy-loam to clay type. The land users who applied the CTTs are mostly smallholders (with less than 1 ha irrigated land) and they reside in the valley bottoms. The upland areas, where the CTT have been constructed, belong to the state but the local communities have land and water use rights. From a climate change perspective, CTTs will not be much affected by temperature changes or drought. Some trenches could break if there is an extreme rainfall event.

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:

Afghanistan

Region/ State/ Province:

Bamyan Province

Further specification of location:

Kahmard district

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • through projects/ external interventions
Comments (type of project, etc.):

The project started in 2008.

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation
  • reduce risk of disasters

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

Grazing land

Grazing land

Extensive grazing land:
  • Semi-nomadism/ pastoralism
Comments:

Major land use problems (compiler’s opinion): Depleted soils, poor vegetative cover, deep gullies leading which trigger severe flash floods.

Major land use problems (land users’ perception): Severe flash floods from the degraded watershed.

Future (final) land use (after implementation of SLM Technology): Mixed: Mo: Other

If land use has changed due to the implementation of the Technology, indicate land use before implementation of the Technology:

Grazing land: Ge: Extensive grazing land

3.3 Further information about land use

Water supply for the land on which the Technology is applied:
  • rainfed
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 180; Longest growing period from month to month: March to July

3.4 SLM group to which the Technology belongs

  • area closure (stop use, support restoration)
  • cross-slope measure
  • water diversion and drainage

3.5 Spread of the Technology

Specify the spread of the Technology:
  • evenly spread over an area
If the Technology is evenly spread over an area, indicate approximate area covered:
  • 1-10 km2
Comments:

Total area covered by the SLM Technology is 3 km2.

About 65,000 trenches each measuring 5 m in length x 0.7 m in depth and 0.7 m in width (in middle) were constructed manually.

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S4: Level ditches, pits

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wo: offsite degradation effects
biological degradation

biological degradation

  • Bc: reduction of vegetation cover
Comments:

Secondary types of degradation addressed: Bc: reduction of vegetation cover

Main causes of degradation: over-exploitation of vegetation for domestic use (Shrubs used for fuel), overgrazing (Mainly by sheep and goats), governance / institutional (No management system either by the government or local communities)

Secondary causes of degradation: droughts (Slow recovery of natural vegetation), population pressure, war and conflicts (Cutting of Juniper trees)

3.8 Prevention, reduction, or restoration of land degradation

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

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

4.1 Technical drawing of the Technology

Author:

Ahmad Ali Sediqi, HELVETAS Swiss Intercooperation

4.2 Technical specifications/ explanations of technical drawing

Technical specifications of Contour Tied Trench with soil bunds constructed at Sourakhak wa-tershed. Fruit and non-fruit trees have been planted at a few selected sites in the watershed as vegetative measures. The plant survival per cent was about 10% due to drought, rodent problem and poor adaptation of the tree saplings brought from a different natural environment. The sites are protected from grazing and shrub cutting leading to better land cover.

The trenches have the capacity to store about 159,250 cu.m of water. Kahmard receives up to 350 mm rainfall per year. Considering catchment area of 3 km2 the trenches can hold all the water if there was 50 mm rain at a time, which is rare.Trench size: 5 m (L), 1m at top and 0.4 m at bottom (W), 0.7 m (D)
Distance between trench in a row = 0.3-0.7 m and spacing between contours = 4-8 m depending on the slope (steeper slopes have less distance)

Soil bund size: 5.5 m (L), 0.7 m/0.4 m (W), 0.5 m (H)

The trenches have the capacity to store about 159,250 cu.m of water. Kahmard receives up to 350 mm rainfall per year. Considering catchment area of 3 km2 the trenches can hold all the water if there was 50 mm rainfall at a time, which is rare.

Location: Afghanistan. Kahmard/Bamyan

Date: 12/12/2012

Technical knowledge required for field staff / advisors: high (Initial stages. It is a new technology for most field staff.)

Technical knowledge required for land users: high (Initial stages. Land users have to learn first where to apply, how to apply and maintain this technology and also the method for preparing contour lines.)

Main technical functions: control of dispersed runoff: retain / trap

Secondary technical functions: reduction of slope length, increase of infiltration

Retention/infiltration ditch/pit, sediment/sand trap
Spacing between structures (m): 4-8
Depth of ditches/pits/dams (m): 0.7
Width of ditches/pits/dams (m): 0.7
Length of ditches/pits/dams (m): 5
Height of bunds/banks/others (m): 0.5
Width of bunds/banks/others (m): 0.7
Length of bunds/banks/others (m): 5.5

4.3 General information regarding the calculation of inputs and costs

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

5.00

4.4 Establishment activities

Activity Type of measure Timing
1. construction of trenches Structural summer and autumn

4.5 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Construction of trenches persons/day/ha 276.0 5.0 1380.0 10.0
Equipment Tools ha 1.0 70.0 70.0 90.0
Total costs for establishment of the Technology 1450.0
Comments:

Duration of establishment phase: 36 month(s)

4.6 Maintenance/ recurrent activities

Activity Type of measure Timing/ frequency
1. Repair trenches Structural Spring/once per year

4.7 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 trenches persons/day/ha 1.0 5.0 5.0 100.0
Total costs for maintenance of the Technology 5.0
Comments:

Machinery/ tools: Shovel

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Labour

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.

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):
  • coarse/ light (sandy)
  • fine/ heavy (clay)
Topsoil organic matter:
  • low (<1%)
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 fertility is low - medium

Soil drainage / infiltration is medium - good

Soil water storage capacity is medium

5.4 Water availability and quality

Availability of surface water:

medium

Water quality (untreated):

poor drinking water (treatment required)

Comments and further specifications on water quality and quantity:

Availability of surface water: During rainy seasons

Water quality (untreated): Not good but used for animal drinking water using traditional water harvesting structures

5.5 Biodiversity

Species diversity:
  • low
Comments and further specifications on biodiversity:

Gradually improving

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
Individuals or groups:
  • groups/ community
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 are not allowed to work in these areas due to local customs.

Population density: 10-50 persons/km2

Annual population growth: 2% - 3%

Relative level of wealth: rich, average, poor

10% of the land users are rich.
40% of the land users are average wealthy.
50% of the land users are poor.

Market orientation of production system: Income from selling sheep and goats and items from livestotck products like carpets.

5.7 Average area of land owned or leased 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:
  • state
Land use rights:
  • communal (organized)
Water use rights:
  • communal (organized)
Comments:

Land is used by families of three community development councils in Kahmard district as common land

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

fodder production

decreased
increased
Comments/ specify:

Increase in natural production due to increased moisture and area protection

production area

decreased
increased
Comments/ specify:

As the area is closed for grazing and shrub cutting

Socio-cultural impacts

community institutions

weakened
strengthened
Comments/ specify:

Work is facilitated by watershed management committee

SLM/ land degradation knowledge

reduced
improved

livelihood and human well-being

reduced
improved
Comments/ specify:

It has reduced flash flood risks. As a result, more area in the valleys is productive and damages to houses, roads, gardens, agriculture land have significantly reduced

Ecological impacts

Water cycle/ runoff

harvesting/ collection of water

reduced
improved

groundwater table/ aquifer

lowered
recharge
Soil

soil moisture

decreased
increased
Biodiversity: vegetation, animals

plant diversity

decreased
increased

6.2 Off-site impacts the Technology has shown

downstream flooding

increased
reduced

damage on neighbours' fields

increased
reduced
Comments/ specify:

Due to less flash floods

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 Type of climatic change/ extreme 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 not well
Climatological disasters
How does the Technology cope with it?
drought well

Other climate-related consequences

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

Stabilize CTTs with vegetative and management measures. Trench size should be based on hydro-meteorological parameters considering possibility of an extreme event occurring.

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:

very positive

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

positive

Long-term returns:

very positive

6.5 Adoption of the Technology

Comments:

100% of land user families have adopted the Technology with external material support

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Reduce flash floods risks
Helps in spring recharge

How can they be sustained / enhanced? CTTs should be maintained and combined with vegetation measures for better infiltration.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Reduce flash floods risks

How can they be sustained / enhanced? Maintenance and application of vegetative measures along with the trenches. For Instance planting of perennial forage species on the bunds like Alfalfa, Agropyron and Sainfoin..
CTTs considered better than staggered contour trench if the purpose is to control flash floods as it can trap more runoff and have less chances of damages

How can they be sustained / enhanced? Maintenance and correct implementation is necessary
Helps in the establishment of vegetation due to more soil moisture

How can they be sustained / enhanced? Combine with conservation practices like mulching
Potential technology for reducing flash flood risks

How can they be sustained / enhanced? More training and awareness about the limitations of this technology - where to apply and where not to apply

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?
Soil disturbed during digging and fine clay deposits in the trenches which reduces infiltration Apply conservation trenches. Planting on the either ends of the trench and soil working to break the clay layering.
Establishment costs are high Initial external support necessary. Linking relief to sustainable land management could be an option.
Loss of land for production due to trenching ntegrate planting of trees and grasses.
Trenches break CTTs must be of right size along the contour lines. Workers must be trained before implementation work and there must be proper supervision. The size of a trench and spacing between trenches should be based on hydro-met parameters. Also, avoid steep sandy (blue) and shallow rocky soil beds

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