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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)
Catholic Relief Services
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)HELVETAS (Swiss Intercooperation)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)Catholic Relief Services/East Africa (Catholic Relief Services/East Africa) - Kenya
1.3 Conditions regarding the use of data documented through WOCAT
When were the data compiled (in the field)?
The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:
1.5 Reference to Questionnaire(s) on SLM Approaches
2. Description of the SLM Technology
2.1 Short description of the Technology
Definition of the Technology:
Contour trench bund applied on contour lines of moderate slope to trap run-off to improve infiltration and reduce flash floods.
2.2 Detailed description of the Technology
The Contour Trench Bund technology is documented by Sustainable Land Management
Project/HELVETAS Swiss Intercooperation with financial support of Swiss Agency for
Development and Cooperation(SDC) and close support and cooperation of the Catholic
Relief Service (CRS). The technology was applied in Sar-e Ahengaran watershed of Bamyan centre, an area of 0.08 km2 as part of a watershed project by the Catholic Relief Services (CRS). The total watershed area is 67 ha. The project started in October 2009 involving the community with funding support from USAID and CRS. The project came to an end in March 2013.
Purpose of the Technology: The main purpose of the contour trench bund technology is to reduce excessive surface runoff and improve infiltration. It also contributes to increased vegetation cover.
Establishment / maintenance activities and inputs: The main activities for this SLM technology include: site selection and technical planning in October 2009; demarcation of contour lines using A-frame and lime; and digging trenches and construction of soil bunds. The technology was established over 10 months. The project used a “Cash for Work” approach; local people were employed for construction works. Cost-wise, approximately 7,536 USD were spent on this technology (approximately 942 USD/ha) with 90% contribution from the project and 10% from the participating community. There have been no maintenance costs so far for this technology.
Dimensions of a trenches are: 0.7 m in depth, 1.2 m width, 3 m length and of the bunds: 0.45 m in height, 1.2 m in width, 100 m in length with 12 m spacing and 1.5 m vertical interval between two contour lines. Contour trenches were applied on hilly (16-30%) slopes at an altitude of 2500-3000 m. The technology is tolerant to temperature, seasonal rainfall, storms and droughts and sensitive to heavy rainfall events and floods. The soil in the watershed is sandy to loamy type, and infertile with a depth of 20-50 cm. The infiltration is medium.
The technology is part of the watershed management system. Other measures implemented included stone walls, cultivation of fodder grasses and ban on grazing and shrub cutting at the site. The land ownership (in the watershed) is communal with open access water rights. Medium scale land users, mainly men, applied the technology. Women and school children participated in meetings concerning awareness raising. There is also a watershed and pasture management committee for site management.
Natural / human environment: The annual rainfall in the area is 250-500 mm. The agro-climate is semi-arid and temperate type with the longest growing period of 180 days from April to October. The people in this area are mainly poor. 10-50 % of all income comes from off-farm activities. Access to health, market and financial services is low and education, roads, transport, drinking water and sanitation facilities are moderate. Agriculture is of mixed type, subsistence and commercial based.
2.3 Photos of the Technology
2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment
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
3. Classification of the SLM Technology
3.1 Main purpose(s) of the Technology
- protect a watershed/ downstream areas – in combination with other Technologies
- reduce risk of disasters
3.2 Current land use type(s) where the Technology is applied
Extensive grazing land:
- Semi-nomadism/ pastoralism
Main animal species and products:
Sheeps, goats and cattle
Major land use problems (compiler’s opinion): Reduction of the vegetation cover causes flash floods and accelerated erosion. The water level goes down and there is no moisture in the soil.
Major land use problems (land users’ perception): Downstream flash flood and shortage of spring water due to overgrazing of the range-land.
Future (final) land use (after implementation of SLM Technology): Grazing land: Gi: Intensive grazing/ fodder production
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:
- mixed rainfed-irrigated
Number of growing seasons per year:
Longest growing period in days: 180; Longest growing period from month to month: April to October
Livestock density (if relevant):
10-25 LU /km2
3.4 SLM group to which the Technology belongs
- improved ground/ vegetation cover
- cross-slope measure
3.5 Spread of the Technology
Total area covered by the SLM Technology is 0.08 km2.
3.6 SLM measures comprising the Technology
- S2: Bunds, banks
- S4: Level ditches, pits
Main measures: structural measures
3.7 Main types of land degradation addressed by the Technology
soil erosion by water
- Wt: loss of topsoil/ surface erosion
Main causes of degradation: over-exploitation of vegetation for domestic use, overgrazing
3.8 Prevention, reduction, or restoration of land degradation
Specify the goal of the Technology with regard to land degradation:
- reduce land degradation
4. Technical specifications, implementation activities, inputs, and costs
4.1 Technical drawing of the Technology
4.2 Technical specifications/ explanations of technical drawing
The technical drawing of the Contour trench bund showing the layout and dimensions/spacing of the structures.
Dimensions of the trench and bund are as following:
Depth: 0.7 m,
Width: 1.2 m, Length: 3 m
Soil bund specifications:
Height: 0.45 m
Width: 1.2 m
Length: 100 m
Spacing between contour lines:
About 8 -12 m (depend on slop)
Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: moderate
Main technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, increase of infiltration
Secondary technical functions: reduction of slope length, increase of groundwater level / recharge of groundwater, sediment retention / trapping, sediment harvesting
4.3 General information regarding the calculation of inputs and costs
Specify currency used for cost calculations:
- US Dollars
4.4 Establishment activities
|Activity||Type of measure||Timing|
|1.||Demarcation of the contour lines using A frame and Lime||Structural|
|2.||Excavation of the trenches and construction of the soil bunds||Structural|
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||Demarcation of the contour lines||ha||1.0||92.0||92.0|
|Labour||Excavation of the trenches and construction of the soil bunds||persons/day/ha||121.0||7.0||847.0||10.0|
|Total costs for establishment of the Technology||939.0|
Duration of establishment phase: 10 month(s)
4.6 Maintenance/ recurrent activities
|Activity||Type of measure||Timing/ frequency|
|1.||No maintenance costs so far for CRS.||Structural|
4.8 Most important factors affecting the costs
Describe the most determinate factors affecting the costs:
The establishment duration of the Contour Trench Bund was 10 months.
5. Natural and human environment
- < 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
Thermal climate class: Temperate
Slopes on average:
- flat (0-2%)
- gentle (3-5%)
- moderate (6-10%)
- rolling (11-15%)
- hilly (16-30%)
- steep (31-60%)
- very steep (>60%)
- mountain slopes
- hill slopes
- valley floors
- 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.
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)
- medium (loamy, silty)
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
Soil water storage capacity is medium
5.4 Water availability and quality
Ground water table:
Availability of surface water:
Water quality (untreated):
good drinking water
5.6 Characteristics of land users applying the Technology
Market orientation of production system:
- mixed (subsistence/ commercial
- 10-50% of all income
Relative level of wealth:
Individuals or groups:
- groups/ community
Indicate other relevant characteristics of the land users:
Difference in the involvement of women and men: Workload does not give chance to women to work on the mountains.
Population density: < 10 persons/km2
Annual population growth: 2% - 3%
50% of the land users are poor.
Off-farm income specification: Busy with carpentry and migrate for work.
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)?
5.8 Land ownership, land use rights, and water use rights
- communal/ village
Land use rights:
- communal (organized)
Water use rights:
- open access (unorganized)
5.9 Access to services and infrastructure
employment (e.g. off-farm):
roads and transport:
drinking water and sanitation:
6. Impacts and concluding statements
6.1 On-site impacts the Technology has shown
Due to better soil moisture
Income and costs
diversity of income sources
SLM/ land degradation knowledge
situation of socially and economically disadvantaged groups
livelihood and human well-being
Due to reduction in flash floods problem and increased access to drinking water, Seasonal job opportunities created through cash for work
Water cycle/ runoff
harvesting/ collection of water
of surface run off
groundwater table/ aquifer
Biodiversity: vegetation, animals
biomass/ above ground C
Due to more moisture
Climate and disaster risk reduction
Other ecological impacts
disturbance of soil and vegetation during excavation works
6.2 Off-site impacts the Technology has shown
damage on agriculture fields
As the site is closed, grazing pressure shifts elsewhere
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?|
Climate-related extremes (disasters)
|How does the Technology cope with it?|
|How does the Technology cope with it?|
Other climate-related consequences
Other climate-related consequences
|How does the Technology cope with it?|
|Extreme precipitation events especially if the technology is applied on steep slopes.||not well|
Increase size, stable bunds stabilized with vegetation
6.4 Cost-benefit analysis
How do the benefits compare with the establishment costs (from land users’ perspective)?
How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
The benefits will be more in the long term when trees, shrubs and fodder grasses are ready to harvest.
6.5 Adoption of the Technology
Comments on acceptance with external material support: Appropriate information is not available.
Comments on spontaneous adoption: Only soil bunds have been applied by a few farmers on their private lands.
6.7 Strengths/ advantages/ opportunities of the Technology
|Strengths/ advantages/ opportunities in the land user’s view|
The technology helps to create SLM based job opportunities for many people.
How can they be sustained / enhanced? Needs external support/projects.
|Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view|
Demonstration of link between SLM measures and water source.
How can they be sustained / enhanced? Conducting training and showing drawing.
Technical knowledge of community enhanced.
How can they be sustained / enhanced? Share more aspects of the technology, where to apply and how.
Flood reduction, greening of the area, increase the spring water.
How can they be sustained / enhanced? Cultivate native plants, share experiences with more communities and SLM specialists.
Good for land rehabilitation (extremely degraded lands).
How can they be sustained / enhanced? Always combine with vegetative and management measures.
6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them
|Weaknesses/ disadvantages/ risks in the land user’s view||How can they be overcome?|
|Farmers do not prefer to construct this technology because it requires soil excavation/disturbance.||One needs to show how such measures have been applied in other parts of the world for multiple benefits through action research.|
|Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view||How can they be overcome?|
|Site selection||Apply technology at suitable site that has proper slope and is really degraded. Avoid places where there is already good vegetation cover.|
|Higher cost of establishment of the technology.||Encourage the community for more contribution or apply where absolutely necessary.|
|Technical design||The designer should research more about the site and discuss with the skilled people of the community before designing.|
|Few vegetative measures||plant fodder grasses and adapted trees between trenches.|