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

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

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

2.1 Short description of the Technology

Definition of the Technology:

These consist of stone embankments built in the shape of a semi circle with the tips of the bund on the contour and are arranged in staggered orientation in rows so that overflow from one row will run into the next downslope.

2.2 Detailed description of the Technology

Description:

Large semi circular stone bunds are constructed by excavating a foundation of 0.1 - 0.2 m following the semi circle and building of the embankment using stones with a decreasing height at the tips to evacuate excess runoff. 1 - 3 pits are excavated within the semi circle for for planting trees.

Large semi circular stone bunds (Large half moons) are constructed with a diameter of 6 m and corresponding perimeter/length of 9.42 m. The spacing between the tips of adjacent bunds within a row and between the base bund and tip of adjacent rows is 3 m. The height of the embankment varies from 0.5 - 0.75 m at the base bund to 0.4 - 0.5 m at the tip while the corresponding width varies from 0.4 - 0.5 m to 0.2 - 0.3 m. The planting pit has a diameter and depth of 0.3 m.

Purpose of the Technology: Large semi circular stone bunds assist in decreasing slope length, runoff velocity and soil loss; and improving runoff harvesting, soil moisture and groundwater recharge.

Establishment / maintenance activities and inputs: The establishment of large semi circular stone bunds involves collection of stones, alignment of a contour and the semi circle, excavation of foundation, construction of the embankment and digging of planting pits and runoff harvesting ditch. The maintenance includes re-enforcing the embankment and dredging sediment from runoff harvesting ditch during the dry season.

Natural / human environment: Large semi circular stone bunds are implemented in foot (5 - 8%) and hill (8 - 16%) slopes and in medium and light soil types of shallow to moderate depth (0.2 - 0.8 m). It reduces runoff amount and velocity thereby decreasing soil loss and desertification/land degradation. It also improves soil moisture availability and groundwater recharge.

It is mostly constructed using communal labour and there is a moderate trend of spontaneous adoption. The technology is witnessed to be increasing fruit and fodder production thereby improving the livelihood of the land users. It, however, demands high labour especially during establishment.

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:

Ethiopia

Region/ State/ Province:

Tigray

Further specification of location:

Kilte Awlaelo

Specify the spread of the Technology:

• evenly spread over an area

If precise area is not known, indicate approximate area covered:

• 10-100 km2

Map

×

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

3.1 Main purpose(s) of the Technology

• reduce, prevent, restore land degradation

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

Cropland

• Tree and shrub cropping

Tree and shrub cropping - Specify crops:

• citrus
• mango, mangosteen, guava

• lemon, guava

Number of growing seasons per year:

• 1

Specify:

Longest growing period in days: 150 Longest growing period from month to month: June - November

Forest/ woodlands

Products and services:

• Timber
• Fuelwood
• Fruits and nuts
• Grazing/ browsing
• Nature conservation/ protection

Comments:

Major land use problems (compiler’s opinion): Deforestation, soil erosion, overgrazing, decline of soil fertility and productivity.

Major land use problems (land users’ perception): Decrease soil moisture, drought, soil erosion, decrease fodder production and shortage of fuel wood.

Plantation forestry: Deforestation

Forest products and services: timber, fuelwood, fruits and nuts, grazing / browsing, nature conservation / protection

3.4 Water supply

Water supply for the land on which the Technology is applied:

• rainfed

3.5 SLM group to which the Technology belongs

• cross-slope measure
• ground water management

3.6 SLM measures comprising the Technology

structural measures

• S2: Bunds, banks

Comments:

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
• Wg: gully erosion/ gullying
• Wo: offsite degradation effects

biological degradation

• Bc: reduction of vegetation cover
• Bs: quality and species composition/ diversity decline

Comments:

Main type of degradation addressed: Wt: loss of topsoil / surface erosion

Secondary types of degradation addressed: Wg: gully erosion / gullying, Wo: offsite degradation effects, Bc: reduction of vegetation cover, Bs: quality and species composition /diversity decline

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires), Heavy / extreme rainfall (intensity/amounts), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Steep topography), population pressure

Secondary causes of degradation: over-exploitation of vegetation for domestic use, overgrazing, droughts, land tenure, poverty / wealth, education, access to knowledge and support services

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: rehabilitation / reclamation of denuded land

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Large semi circular stone bunds are stone embankments built in the shape of a semi circle with the tips of the bund on the contour and are arranged in staggered orientation in rows so that overflow from one row will run into the next downslope.

Location: Tigray. Kilte Awlaelo

Date: 10/10/2014

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: low

Main technical functions: control of dispersed runoff: retain / trap, reduction of slope length

Secondary technical functions: increase of infiltration, increase / maintain water stored in soil, increase of groundwater level / recharge of groundwater, sediment retention / trapping, sediment harvesting, increase of biomass (quantity)

Bund/ bank: semi-circular/V shaped trapezoidal
Vertical interval between structures (m): 0.2 - 0.3
Spacing between structures (m): 3
Depth of ditches/pits/dams (m): 1
Width of ditches/pits/dams (m): 1
Length of ditches/pits/dams (m): 1
Height of bunds/banks/others (m): 0.5 - 0.75
Width of bunds/banks/others (m): 0.4 - 0.5
Length of bunds/banks/others (m): 9.42

Construction material (stone): The embankment of the semi circular bunds is constructed by the stones.

Slope (which determines the spacing indicated above): 6.5 and 12%

Lateral gradient along the structure: 0%

Author:

Eyasu Yazew, P.O.Box 231, Mekelle University, Mekelle, Ethiopia

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Birr

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

18.0

4.3 Establishment activities

4.4 Costs and inputs needed for establishment

Comments:

Duration of establishment phase: 24 month(s)

4.5 Maintenance/ recurrent activities

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

Comments:

Machinery/ tools: Line level, tape meter, digging hoe, shovel, hammer

The cost was calculated for a semi circular bund of 6 m diameter, spacing between the tips of adjacent bunds within a row of 3 m and spacing between a base bund of one row and the tip of the next row of 3 m. This arrangement results in a construction of 2.5 bunds over 94.5 square meter area and a total of 264 bunds per ha.

The construction of one large semi circular stone bund and excavation of the planting pits and runoff harvesting ditch requires 5 person days during establishment while maintaining it needs 0.2 person days.The cost calculation rates apply to 2012. Accordingly, the daily labour wage is 40 Birr for light work such as sediment dredging and 50 Birr for medium work such as stone collection.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Labour, slope, stone availability and size.

5.1 Climate

5.2 Topography

Comments and further specifications on topography:

Slopes on average: An average slope of 6.5% is taken for moderate/foot slope and 12% for hill slope.

5.3 Soils

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 depth on average: Shallow (ranked 1) and moderately deep (Fruit tree plantation on deeper soils, ranked 2)
Soil fertility is low (medium soils, ranked 1) and very low (Light soils, ranked 2)
Soil drainage/infiltration is poor (ranked 1) and medium (ranked 2, Drainage is restricted by the soil depth)
Soil water storage capacity is medium (Medium soils, ranked 1) and low (light soils, ranked 2)

5.4 Water availability and quality

5.5 Biodiversity

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

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

Population density: 100-200 persons/km2

Annual population growth: 2% - 3%

10% of the land users are rich and own 10% of the land.
60% of the land users are average wealthy and own 55% of the land (35 Birr/day/person).
30% of the land users are poor and own 35% of the land.

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

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

Land ownership:

• state

Land use rights:

• communal (organized)
• individual

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

6.2 Off-site impacts the Technology has shown

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)?

6.5 Adoption of the Technology

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

2820

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?

• 11-50%

Comments:

70% of land user families have adopted the Technology with external material support

1880 land user families have adopted the Technology with external material support

30% of land user families have adopted the Technology without any external material support

940 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

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

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Staff members of the Kilte Awlaelo Wereda Office of Agriculture and Rural Development

Title, author, year, ISBN:

Carucci, V. (2000). Guidelines on Water Harvesting and Soil Conservation for Moisture Deficit Areas in Ethiopia:the productive use of water and soil. First draft manual for trainers, Addis Ababa, Ethiopia.

Title, author, year, ISBN:

Lakew, D., Carucci, V., Asrat, W. and Yitayew, A. (2005). Community Based Participatory Watershed Development: A guideline. Part I, first edition, Ministry of Agriculture and Rural Development, Addis Ababa, Ethiopia.