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Stone faced trench (Ethiopia)

Emnigetsu metrebawi zala

Description

Construction of stones walls along the contour with trenches on the upper side of the structure while the upper part of the structure filled with soil and compacted.

allignment of the soil along the contour, diiging of foundation, trench construction, spacing tie ridge, tree planting,

Purpose of the Technology: reduce erosion, increase soil moisture, recharge ground water, decrease ground water

Establishment / maintenance activities and inputs: stone wall construction, trench digging, tree and forage planting, area closure

Natural / human environment: enhance vegetation growth, decrease desertification, increase biodiversity

Location

Location: Atsbi Womberta, Tigray, Ethiopia

No. of Technology sites analysed:

Geo-reference of selected sites
  • 39.0, 13.0

Spread of the Technology:

In a permanently protected area?:

Date of implementation: more than 50 years ago (traditional)

Type of introduction

Classification of the Technology

Main purpose
  • improve production
  • reduce, prevent, restore land degradation
  • conserve ecosystem
  • protect a watershed/ downstream areas – in combination with other Technologies
  • preserve/ improve biodiversity
  • reduce risk of disasters
  • adapt to climate change/ extremes and its impacts
  • mitigate climate change and its impacts
  • create beneficial economic impact
  • create beneficial social impact
Land use

  • Grazing land
  • Forest/ woodlands
    • (Semi-)natural forests/ woodlands. Management: Clear felling
    • Tree plantation, afforestation
    Products and services: Fuelwood, Other forest products, Nature conservation/ protection, Cut and carry
Water supply
  • rainfed
  • mixed rainfed-irrigated
  • full irrigation
Purpose related to land degradation
  • prevent land degradation
  • reduce land degradation
  • restore/ rehabilitate severely degraded land
  • adapt to land degradation
  • not applicable
Degradation addressed
  • soil erosion by water - Wt: loss of topsoil/ surface erosion, Wg: gully erosion/ gullying
  • chemical soil deterioration - Cn: fertility decline and reduced organic matter content (not caused by erosion)
  • water degradation - Ha: aridification
SLM group
  • cross-slope measure
SLM measures

Technical drawing

Technical specifications

Establishment and maintenance: activities, inputs and costs

Calculation of inputs and costs
  • Costs are calculated:
  • Currency used for cost calculation: birr
  • Exchange rate (to USD): 1 USD = 8.0 birr
  • Average wage cost of hired labour per day: 0.88
Most important factors affecting the costs
labour, slope, low survival rate of seedlings
Establishment activities
  1. seedling production (Timing/ frequency: July-June)
  2. pitting (Timing/ frequency: April-May)
  3. planting (Timing/ frequency: July)
  4. over sawing of grasses (Timing/ frequency: July)
  5. survey & layout (Timing/ frequency: Dec.-April)
  6. collection of stones (Timing/ frequency: Dec.-April)
  7. digging foundation & trench (Timing/ frequency: Dec.-April)
  8. construction (Timing/ frequency: Jan.-April)
  9. site guard (Timing/ frequency: the whole year)
  10. enrichment plantation and replanting (Timing/ frequency: onset of rainy season)
Establishment inputs and costs
Specify input Unit Quantity Costs per Unit (birr) Total costs per input (birr) % of costs borne by land users
Labour
Labour ha 1.0 234.0 234.0 10.0
Harvesting ha 1.0 45.0 45.0
Equipment
Tools ha 1.0 14.0 14.0 5.0
Plant material
Seedlings ha 1.0 86.0 86.0
Total costs for establishment of the Technology 379.0
Total costs for establishment of the Technology in USD 47.38
Maintenance activities
  1. replanting (Timing/ frequency: July /once)
  2. stone collection (Timing/ frequency: January/once)
Maintenance inputs and costs
Specify input Unit Quantity Costs per Unit (birr) Total costs per input (birr) % of costs borne by land users
Labour
Labour ha 1.0 4.0 4.0 100.0
Total costs for maintenance of the Technology 4.0
Total costs for maintenance of the Technology in USD 0.5

Natural environment

Average 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
  • humid
  • sub-humid
  • semi-arid
  • arid
Specifications on climate
Average annual rainfall in mm: 300.0
Slope
  • 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
Altitude
  • 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.
Technology is applied in
  • convex situations
  • concave situations
  • not relevant
Soil depth
  • 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)
  • fine/ heavy (clay)
Soil texture (> 20 cm below surface)
  • coarse/ light (sandy)
  • medium (loamy, silty)
  • fine/ heavy (clay)
Topsoil organic matter content
  • high (>3%)
  • medium (1-3%)
  • low (<1%)
Groundwater table
  • on surface
  • < 5 m
  • 5-50 m
  • > 50 m
Availability of surface water
  • excess
  • good
  • medium
  • poor/ none
Water quality (untreated)
  • good drinking water
  • poor drinking water (treatment required)
  • for agricultural use only (irrigation)
  • unusable
Is salinity a problem?
  • Yes
  • No

Occurrence of flooding
  • Yes
  • No
Species diversity
  • high
  • medium
  • low
Habitat diversity
  • high
  • medium
  • low

Characteristics of land users applying the Technology

Market orientation
  • subsistence (self-supply)
  • mixed (subsistence/ commercial)
  • commercial/ market
Off-farm income
  • less than 10% of all income
  • 10-50% of all income
  • > 50% of all income
Relative level of wealth
  • very poor
  • poor
  • average
  • rich
  • very rich
Level of mechanization
  • manual work
  • animal traction
  • mechanized/ motorized
Sedentary or nomadic
  • Sedentary
  • Semi-nomadic
  • Nomadic
Individuals or groups
  • individual/ household
  • groups/ community
  • cooperative
  • employee (company, government)
Gender
  • women
  • men
Age
  • children
  • youth
  • middle-aged
  • elderly
Area used per household
  • < 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
Scale
  • small-scale
  • medium-scale
  • large-scale
Land ownership
  • state
  • company
  • communal/ village
  • group
  • individual, not titled
  • individual, titled
Land use rights
  • open access (unorganized)
  • communal (organized)
  • leased
  • individual
Water use rights
  • open access (unorganized)
  • communal (organized)
  • leased
  • individual
Access to services and infrastructure

Impacts

Socio-economic impacts
Crop production
decreased
x
increased

fodder production
decreased
x
increased

fodder quality
decreased
x
increased

wood production
decreased
x
increased

production area (new land under cultivation/ use)
decreased
x
increased

farm income
decreased
x
increased

Honey production
decreased
x
increased

Socio-cultural impacts
community institutions
weakened
x
strengthened

SLM/ land degradation knowledge
reduced
x
improved

Ecological impacts
excess water drainage
reduced
x
improved

soil moisture
decreased
x
increased

soil cover
reduced
x
improved

soil loss
increased
x
decreased

Biodiversity
decreased
x
increased

Soil fertility
decreased
x
increased

Off-site impacts
reliable and stable stream flows in dry season (incl. low flows)
reduced
x
increased

downstream flooding (undesired)
increased
x
reduced

downstream siltation
increased
x
decreased

groundwater/ river pollution
increased
x
reduced

Cost-benefit analysis

Benefits compared with establishment costs
Short-term returns
very negative
x
very positive

Long-term returns
very negative
x
very positive

Benefits compared with maintenance costs
Short-term returns
very negative
x
very positive

Long-term returns
very negative
x
very positive

Climate change

-

Adoption and adaptation

Percentage of land users in the area who have adopted the Technology
  • single cases/ experimental
  • 1-10%
  • 11-50%
  • > 50%
Of all those who have adopted the Technology, how many have done so without receiving material incentives?
  • 0-10%
  • 11-50%
  • 51-90%
  • 91-100%
Has the Technology been modified recently to adapt to changing conditions?
  • Yes
  • No
To which changing conditions?
  • climatic change/ extremes
  • changing markets
  • labour availability (e.g. due to migration)

Conclusions and lessons learnt

Strengths: land user's view
  • highly appreciate the construction of the trench because it enhance soil miosture and improve productivity of land and cropproduction.
Strengths: compiler’s or other key resource person’s view
  • it has a great contribution for the sustainability of production
  • increase the flow of streams
  • recharge and increase water table
Weaknesses/ disadvantages/ risks: land user's viewhow to overcome
  • restricts free grazing allow cut and carry from the area closure
Weaknesses/ disadvantages/ risks: compiler’s or other key resource person’s viewhow to overcome
  • it needs much labour during construction mobilize the community
  • it takes land out of production integrate the technology with other vegetative measures in order to increase the productivity of land including the areas ocuppied by the structure

References

Compiler
  • Unknown User
Editors
Reviewer
  • Fabian Ottiger
  • Alexandra Gavilano
Date of documentation: Feb. 28, 2011
Last update: Sept. 9, 2019
Resource persons
Full description in the WOCAT database
Linked SLM data
Documentation was faciliated by
Institution Project
This work is licensed under Creative Commons Attribution-NonCommercial-ShareaAlike 4.0 International