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Technologies
Inactive

Gully erosion management [Ethiopia]

Borebore lemat (Amharic)

technologies_1597 - Ethiopia

Completeness: 86%

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:
SLM specialist:

Bekure Melese

WLRC

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Water and Land Resource Centre Project (WLRC)

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

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

1.5 Reference to Questionnaire(s) on SLM Approaches

Community Organizations and Mobilization for Soil and Water Conservation Work (COM-SWC)
approaches

Community Organizations and Mobilization for Soil and Water ... [Ethiopia]

Community mobilization for soil and water conservation work in a watershed planning unit is an approach for collective action by organizing all active labor forces living in the kebele/peasant association into development group of 20-30 members and further divide into 1:5 work force to implement construction of soil and water ...

  • Compiler: Gizaw Desta Gessesse
'Cut and Carry' Grazing system or 'Zero Grazing' (CCG)
approaches

'Cut and Carry' Grazing system or 'Zero Grazing' ... [Ethiopia]

Cut and carry grazing system (alternatively called zero grazing) is an approach where the community is consulted to identify and agree on areas to be closed and protected from free grazing; establish user groups are established to share the fodder biomass harvested from communal closed areas equitably; they utilize tree/shrub ...

  • Compiler: Gizaw Desta Gessesse

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Gully erosion management is the application of combination of practices to control excess or concentrated runoff generation in the gully upstream catchment area, divert excess runoff upstream of gully heads and control further development of gully using appropriate structural and vegetative measures in the head, bed and sides of the gully and eventually convert into productive land through the consultation and involvement of local community.

2.2 Detailed description of the Technology

Description:

Gully erosion occurs on cultivated and grazing/pasture lands. Gully erosion management is a practice aimed to rehabilitate and protect further development of gullies and change into productive land. It involves both runoff management and erosion control activities. Gully management and treatment is different at upstream catchment area, gully head and gully section. Proper land management practices and slope treatment measures such as terraces, infiltration ditches and grass or shrub hedgerows are taking place on upstream catchment of the gully in order to reduce the rate of surface runoff. The excess runoff above the gully head is safely drained using cutoff drains into natural or properly vegetated waterways in order to reduce the surface water entering into the gully and protect the constructed physical and biological measures being washed away. Before treating gully sections, for the purpose of stability of structures and quick healing, the gully should be reshaped and planted with grass sod. Gully wall reshaping is cutting off steep slopes of active gully flanks in to gentle slope of minimum at 45% slope, up to two-third of the total depth of the gully and constructing small trenches along contours for re-vegetating slanted part of the gully walls and beds. If the gully is wide and has meandering nature with huge accumulation of runoff flowing down, it requires constructing of retaining walls, to protect displaced (not yet stabilized) soils and soil materials and the sidewalls of the reshaped gully. Stabilization of gully sections involves the use of structural and vegetative measures in the head, floor and side of the gully. The construction of physical structures inside the gully section is followed by establishment of biological measures.

Purposes of gully erosion management are: 1) rehabilitate the land damaged due to gully erosion, 2) prevent further expansion and development of gully erosion, and 3) convert the land lost by gully erosion to productive land.

Gully erosion management begins with assessment and mapping of gully erosion that helps to have an overview of erosion, to document extent of damage, to identify the nature and causes of gully formation, and gives relevant information to design appropriate measures. At establishment stage, gully management requires: catchment treatment using different land treatment measures; runoff diversion by cutoff drain; and stabilization of gully sections by physical structures and vegetative measures. Stones for the construction of terraces, cutoff drains and waterways are required. Depending on the nature of gully and available material for construction, either stones, sand bags, brush woods, bamboo mat, gabion or concrete (sand, gravel and cement) are needed for constructing check-dams in a gully section. Different tree/shrub seedlings, grass cuttings, and seedlings of fruit trees are required to reinforce and stabilize the gully sections. The respective labor requirement for stone collection, construction of retaining wall, and gully reshaping is 0.5m3/person day, 5m/person day, and 1m3/person day. Approximately 0.25, 0.50, 0.50, 0.50 , and 1.0 m3/person day is required to construct gabion, loose stone, arc weir, sand bag, and bamboo mat check-dams respectively. About 3.0 m/person day is needed to construct brushwood check dams. The treated gullies should be checked regularly. The maintenance requirement is closely monitored and immediate repair is essential to avoid further damage and eventual collapse of structures. The inputs important for maintenance include stones or other materials for check dams, seedlings to replant areas covered with non-survived seedlings.

Gully erosion is prevalent in areas where excess runoff occurs in high rainfall areas associated with moderate to high erodible soils. It occurs in range of wet highland to moist Kolla areas where annual rainfall exceeds 900mm. Its occurrence is more frequent in heavy clay soils (Vertisols) characterized by low infiltration and in clay soils (like Nitosols) characterized by low organic matter. Often, gully formation occurs on overgrazed pasture lands and inappropriately managed crop lands. Gully erosion control requires mobilization of high input or materials and labor. Larger gullies need to be rehabilitated and treated through community labor mobilization. Subsequent maintenance activities, monitoring and benefit sharing should be made by the user groups who are entitled to utilize the benefits.

The living condition depends on subsistence crop-livestock mixed farming. On average households have 5-6 family size. Crop production is meant for home consumption with small surplus for local market. The services related to water supply, energy supply, and infrastructure are low. Besides it is an asset, animals often used to cope shocks during drought periods.

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:

Amhara National Regional State (ANRS)

Further specification of location:

Dembecha/Mecha/Yilmana Densa

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:
  • during experiments/ research
  • through projects/ external interventions
Comments (type of project, etc.):

Since gully erosion management requires combination of practices, many actors mainly research, local development actors, community, and project are involved in the development of the technology

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

  • Annual cropping
Grazing land

Grazing land

Extensive grazing land:
  • Semi-nomadism/ pastoralism
Intensive grazing/ fodder production:
  • Cut-and-carry/ zero grazing
Comments:

Major land use problems (compiler’s opinion): Land degradation due to different forms of soil erosion and nutrient depletion, overgrazing, shortage of pasture lands and its low productivity, excessive and inappropriate construction of traditional ditches, and increased pressure on trees for the purpose of fuel wood and timber.
Major land use problems (land users’ perception): Soil erosion and soil nutrient depletion, shortage of cultivated land, shortage of grazing land and wood for fuel wood
The type of grazing is often free grazing on communal grazing lands/pasture, supplemented with crop residues and zero grazing combined with improved forages

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: 220, Longest growing period from month to month: May to December; Second longest growing period in days: 180, Second longest growing period from month to month: June to November

Livestock density (if relevant):

> 100 LU /km2

3.4 SLM group to which the Technology belongs

  • area closure (stop use, support restoration)

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:
  • 10-100 km2

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V1: Tree and shrub cover
  • V2: Grasses and perennial herbaceous plants
structural measures

structural measures

  • S2: Bunds, banks
  • S3: Graded ditches, channels, waterways
  • S4: Level ditches, pits
  • S6: Walls, barriers, palisades, fences
  • S11: Others
Comments:

Type of vegetative measures: aligned: -contour, aligned: -along boundary

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

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

biological degradation

  • Bc: reduction of vegetation cover
Comments:

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires), over-exploitation of vegetation for domestic use, overgrazing, Heavy / extreme rainfall (intensity/amounts), population pressure
Secondary causes of degradation: soil management, crop management (annual, perennial, tree/shrub), urbanisation and infrastructure development (Urbanization and infrastructure development induced excessive compaction, unprotected drainage systems and lead to gully formation), floods, land tenure (Land under undefined or communal use of grazing lands are subject to mismanagement that result in gully formation), poverty / wealth

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

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

4.1 Technical drawing of the Technology

Author:

MOA, 2005, Water and Land Resource Center

4.2 Technical specifications/ explanations of technical drawing

A reshaped gully section treated with an integrated gully control measures including check dams made of loose stone and wooden and vegetative tree/shrub and grass hedgerows planted on the sides of gullies.
Location: Debre Mewi Learning Watershed. Yilmana Densa/West Gojam/Amhara Region
Date: 6/27/2016

Technical knowledge required for field staff / advisors: high (It requires knowledge of peak runoff and runoff management and skills to integrate different measures)
Technical knowledge required for land users: high (It needs skills to construct physical measures, and regular monitoring and maintenance of practices. The users must know and understand the growth nature and harvesting stage tree/shrub, grass species)

Main technical functions: control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, reduction of slope angle
Secondary technical functions: reduction of slope length, improvement of ground cover, stabilisation of soil (eg by tree roots against land slides), increase of infiltration

Aligned: -contour
Vegetative material: T : trees / shrubs, G : grass
Number of plants per (ha): 2600
Spacing between rows / strips / blocks (m): 2-3
Vertical interval within rows / strips / blocks (m): 0.5-1.0
Width within rows / strips / blocks (m): 0.5

Aligned: -graded strips
Vegetative material: T : trees / shrubs

Aligned: -along boundary
Number of plants per (ha): 200
Vertical interval within rows / strips / blocks (m): 1
Width within rows / strips / blocks (m): 1

In blocks
Vegetative material: T : trees / shrubs

Vegetative measure: Alinged along side wall of gully
Vegetative material: T : trees / shrubs
Number of plants per (ha): 6800
Spacing between rows / strips / blocks (m): 2-3.0
Vertical interval within rows / strips / blocks (m): 0.5-1.0
Width within rows / strips / blocks (m): 0.5

Vegetative measure: Aligned along side wall of gully
Vegetative material: T : trees / shrubs
Number of plants per (ha): 4800
Spacing between rows / strips / blocks (m): 2-3.0
Vertical interval within rows / strips / blocks (m): 0.5
Width within rows / strips / blocks (m): 0.5
Vegetative measure: Vegetative material: T : trees / shrubs
Trees/ shrubs species: Susbania sesban, Acacia decurrence, treelucern, Acacia saligna
Grass species: Elphant grass, Sudan grass
Slope (which determines the spacing indicated above): 20-30%%
If the original slope has changed as a result of the Technology, the slope today is (see figure below): 18-25%%
Gradient along the rows / strips: 0.5%

Diversion ditch/ drainage
Depth of ditches/pits/dams (m): 0.3-0.7
Width of ditches/pits/dams (m): 1.2-2.8
Length of ditches/pits/dams (m): 100-250

Waterway
Depth of ditches/pits/dams (m): 0.3
Width of ditches/pits/dams (m): 1.5-2.0

Structural measure: Check dams
Vertical interval between structures (m): 1
Spacing between structures (m): 10-15
Height of bunds/banks/others (m): 1-1.5
Width of bunds/banks/others (m): 1.5-3.5

Construction material (earth): Excavated soil
Construction material (stone): Loose stones for check dam
Construction material (wood): Brush wood for check dam
Slope (which determines the spacing indicated above): 10-18%
If the original slope has changed as a result of the Technology, the slope today is: 8-12%
Vegetation is used for stabilisation of structures.

4.3 General information regarding the calculation of inputs and costs

other/ national currency (specify):

ETB

Indicate exchange rate from USD to local currency (if relevant): 1 USD =:

20.0

Indicate average wage cost of hired labour per day:

2.50

4.4 Establishment activities

Activity Type of measure Timing
1. Seedling preparation Vegetative January-June
2. Seedling Transportation Vegetative June-July
3. Grass split transportation Vegetative June -July
4. Plantation of biological measures inside the gully Vegetative July
5. Surveying Structural Dry season
6. Reshaping of gully Structural Dry season
7. Construction of cutoff drains Structural Dry season
8. Construction of waterways Structural Dry season
9. Construction of stone check dams Structural Dry season

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 labour ha 1.0 8319.0 8319.0 99.0
Equipment animal traction ha 1.0 9.0 9.0 100.0
Equipment tools ha 1.0 901.8 901.8 50.0
Plant material grass ha 1.0 20.0 20.0
Plant material seeds ha 1.0 24.0 24.0
Plant material seedlings ha 1.0 63.45 63.45
Fertilizers and biocides compost/manure ha 1.0 15.86 15.86
Construction material stone ha 1.0 1405.0 1405.0 91.0
Construction material wood ha 1.0 27.6 27.6
Construction material earth ha 1.0 91.2 91.2
Total costs for establishment of the Technology 10876.91
Comments:

Duration of establishment phase: 15 month(s)

4.6 Maintenance/ recurrent activities

Activity Type of measure Timing/ frequency
1. Seedling preparation Vegetative January-June
2. Seedling and grass split transportation Vegetative July
3. Replanting seedlings and grass splits Vegetative July
4. Maintenance of cutoff drains/waterways Structural Dry season (Jan-Apr)
5. Maintenance of check dams Structural Dry season (Jan-Apr)

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 labour ha 1.0 902.0 902.0 67.0
Equipment animal traction ha 1.0 4.5 4.5
Plant material grass ha 1.0 10.3 10.3
Plant material seedlings ha 1.0 33.0 33.0
Fertilizers and biocides compost/manure ha 1.0 8.5 8.5
Construction material stone ha 1.0 50.0 50.0 41.0
Construction material wood ha 1.0 14.4 14.4
Construction material earth ha 1.0 45.6 45.6
Total costs for maintenance of the Technology 1068.3
Comments:

The costs are calculated on hectare basis

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The costs for gully erosion management is dependent upon labor, material and transport costs, workability of the soil and maintenance costs.

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
Specifications/ comments on rainfall:

Monsoon, 5-6 months rain and 6-7 dry months

Agro-climatic zone
  • sub-humid

Thermal climate class: subtropics. The lowest temperature is above 5°C but below 18°C between November to January

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):
  • medium (loamy, silty)
  • fine/ heavy (clay)
Topsoil organic matter:
  • medium (1-3%)
  • low (<1%)

5.4 Water availability and quality

Ground water table:

5-50 m

Availability of surface water:

medium

Water quality (untreated):

poor drinking water (treatment required)

5.5 Biodiversity

Species diversity:
  • low

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • subsistence (self-supply)
Off-farm income:
  • less than 10% of all income
Relative level of wealth:
  • average
Individuals or groups:
  • groups/ community
Level of mechanization:
  • manual work
  • animal traction
Gender:
  • women
  • 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 involved in collecting stones and assisting men on heavy works
Population density: 200-500 persons/km2
Annual population growth: 2% - 3%
80% of the land users are average wealthy.
20% of the land users are poor.
Some land users involve in seasonal labor in towns and sell charcoal

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
Water use rights:
  • open access (unorganized)
  • communal (organized)
Comments:

Land use rights on crop land is individual while on grazing lands it is communal either unorganized or organized in some cases. Water is open accessible in most cases except organized communal utilization for some developed drinking water sources.

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:

Gullies are treated for purpose of improved grass and legume fodder production like napier, susbania, local grasses

product diversity

decreased
increased
Comments/ specify:

Honey, fruits can be diversified under intensive gully development

Income and costs

diversity of income sources

decreased
increased
Comments/ specify:

High fodder biomass provide an opportunity to do fattening; sometimes used to grow fruits;

workload

increased
decreased
Comments/ specify:

Under low productive soil where recovery rate is slow, establishment and maintenance cost of labor is high

Socio-cultural impacts

community institutions

weakened
strengthened
Comments/ specify:

Watershed committee and user groups are established

SLM/ land degradation knowledge

reduced
improved
Comments/ specify:

Awareness of the community on gully management increased

conflict mitigation

worsened
improved
Comments/ specify:

Gullies are stabilized and no more conflict

contribution to human well-being

decreased
increased
Comments/ specify:

Land users are organized into user groups and harvest the biomass (grass and fodder) for livestock feed which result in increased livestock productivity. Some land users attempt to fatten cattle and gain benefit.

Ecological impacts

Water cycle/ runoff

surface runoff

increased
decreased
Comments/ specify:

Significant reduction of damage due to runoff

excess water drainage

reduced
improved
Comments/ specify:

Cutoff drains used to drain excess runoff upstream

groundwater table/ aquifer

lowered
recharge
Soil

soil cover

reduced
improved
Comments/ specify:

Plantation of gullies increase cover and biomass production

soil loss

increased
decreased
Comments/ specify:

Check dams significantly reduce the soil loss from gullies

Biodiversity: vegetation, animals

biomass/ above ground C

decreased
increased

6.2 Off-site impacts the Technology has shown

reliable and stable stream flows in dry season

reduced
increased
Comments/ specify:

Stream size and duration has improved

downstream siltation

increased
decreased

damage on public/ private infrastructure

increased
reduced
Comments/ specify:

Reduction of damage on houses

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

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

Gully erosion management involves combination of biological and physical measures. Strong structural measures and upstream runoff management practices should be applied to tolerate flooding.

6.4 Cost-benefit analysis

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

slightly positive

Long-term returns:

positive

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

positive

Long-term returns:

very positive

Comments:

The short term economic benefits of management of gully erosion include grass and fodder production for livestock feed. While the long term benefits may include product diversification like fruit, fodder, and grass production.

6.5 Adoption of the Technology

Comments:

About 3-5% of the total area of watersheds are treated with gully management. Gullies formed on crop lands and communal grazing lands are management collectively by the community labor with external material support such as gabion and seedlings
Gully management is beyond the capacity of land users. So, they are often supported with seedlings and gabions for large gullies
There is a little trend towards spontaneous adoption of the Technology
Land users show interest and motivation by delineating gully damage areas and control free grazing. They also do fencing with external support for nails and seedlings.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
It increases fodder production
It protects further expansion and damage of settlement areas and infrastructures
It increases the flow of streams
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Gully erosion management provides an immediate fodder for cut-and-carry grazing system and encourages zero grazing
It controls erosion and sediment transport as well it increases stream flows to downstream and subsequently changed to productive area
It reduces conflict among adjacent land holders due to formation of gullies
It does not only reduce degradation but also stabilize the soil, water and vegetation system in the area
It increases the awareness level of farmers about land degradation and its causes

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?
It is labor intensive and sometimes harbor rodents and pests Apply traditional collective action mechanisms
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
It requires high labor for regular monitoring and maintenance of structures and protect from damage by excessive runoff Establish by laws and procedures for collective actions among the user groups

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys
  • interviews with land users

7.2 References to available publications

Title, author, year, ISBN:

Gully Rehabilitation: What Does it Costs to Heal Gullies and Make Productive? WLRC Brief No. 3. June 2015

Available from where? Costs?

www.wlrc-eth.org

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