Technologies

Infilling of gullies with vegetative structures [Tajikistan]

Пуркунии селрохахо

technologies_1450 - Tajikistan

Completeness: 82%

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:

Barotov Bahrom

Welthungerhilfe

Tajikistan

SLM specialist:

Ashurov Bakhtiyor

Welthungerhilfe

Tajikistan

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

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. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Reclamation and infilling of eroded gullies using barriers of willow branches and live mulberry cuttings to trap loess soil from surface water runoff.

2.2 Detailed description of the Technology

Description:

Due to many different factors and mechanisms, soil erosion is at an advanced stage in many of the hilly and mountainous parts of Tajikistan. After disrupting the soil cover in steep areas, starting the process of soil detachment and transportation water runoff gets concentrated into specific areas. As a result, rills develop on the steep areas, and eventually enlarge into gullies.

Purpose of the Technology: To address this problem, low cost barriers are constructed from flexible living branches of a sprouting variety of tree, such as willow. These branches are placed along the gulley at intervals of 3-10 metres, so that they slow down the flow of surface water and trap the sediment, thus eventually filling in the gulley over a period of several years.

Establishment / maintenance activities and inputs: The barriers are designed to slowly help infill eroded gullies by trapping the sediment from muddy surface water runoff. This helps prevent further erosion, increases the amount of land available for pasture, and reduces the risk of mud flows or floods further down the slope.
In gullies no wider than 1-2m, live cuttings from local tree varieties with a diameter of 3-5cm and 1 metre in length can be used to establish horizontal woven barriers across the gulley. The barriers are placed at 3-5m intervals along the gulley, starting at the base.
These barriers are constructed from cuttings that are woven in narrow sections with 5-6cm intervals between them. Enforcement and strengthening of these plugs can be achieved through the use of long branches of locally available mulberry. The height of the plug should not exceed 0.5m. The construction activities start in the spring and within several weeks some of the cuttings begin to sprout and grow. To avoid erosion at the sides of the structure, the cut offs are embedded into the sides of the gulley.

Natural / human environment: Gulley plugging is used in pasture land that suffers from overgrazing, deforestation and trampling, which has resulted in the degradation of the soil. Subsequently, the soil has become more vulnerable to the impact of heavy rain in the spring and autumn months, and is prone to erosion from surface water runoff.

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:

Tajikistan

Region/ State/ Province:

Tajikistan / Khatlon

Further specification of location:

Khovaling / Dorobi

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • < 0.1 km2 (10 ha)
Comments:

Total area covered by the SLM Technology is 0.017 km2.

Approximately an 800 m long eroded gully was reclaimed.

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 technology was developed and promoted using the framework of EC TACIS funded Welthungerhilfe project in Khatlon

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

  • Perennial (non-woody) cropping
Perennial (non-woody) cropping - Specify crops:
  • berries
Grazing land

Grazing land

Extensive grazing:
  • Semi-nomadic pastoralism
Animal type:
  • goats
  • cattle - dairy
  • sheep
Comments:

Livestock density (if relevant):

1-10 LU /km2

Major land use problems (compiler’s opinion): Overgrazing on pasture lands, that leads to reduced vegetation cover and deforestation, contributes greatly to the causes of top soil erosion and gulley formation.

Major land use problems (land users’ perception): Gullies are formed after intensive rainfall events. There is nothing in place to stop this erosion.

Semi-nomadism / pastoralism: cows, goats. sheep

Grazingland comments: There is local grazing on this land, but some areas are subjected to nomadic grazing during the migration of livestock between the winter and summer pastures.

Future (final) land use (after implementation of SLM Technology): Mixed: Mf: Agroforestry

Type of grazing system comments: There is local grazing on this land, but some areas are subjected to nomadic grazing during the migration of livestock between the winter and summer pastures.

3.3 Has land use changed due to the implementation of the Technology?

Has land use changed due to the implementation of the Technology?
  • Yes (Please fill out the questions below with regard to the land use before implementation of the Technology)
Land use mixed within the same land unit:

Yes

Specify mixed land use (crops/ grazing/ trees):
  • Agroforestry
Cropland

Cropland

  • Perennial (non-woody) cropping
Perennial (non-woody) cropping - Specify crops:
  • berries
Grazing land

Grazing land

Extensive grazing:
  • Semi-nomadic pastoralism

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • rainfed
Comments:

Number of growing seasons per year:

1

Specify:

Longest growing period in days: 160Longest growing period from month to month: March - June

3.5 SLM group to which the Technology belongs

  • cross-slope measure

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V1: Tree and shrub cover
structural measures

structural measures

  • S6: Walls, barriers, palisades, fences
Comments:

Main measures: vegetative measures, structural measures

Type of vegetative measures: aligned: -linear

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wg: gully erosion/ gullying
Comments:

Main type of degradation addressed: Wg: gully erosion / gullying

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Trees were cut from a steep slope on the side of the hillside.), overgrazing (Freely grazed area, carrying capacity less than animal numbers grazing.)

Secondary causes of degradation: Heavy / extreme rainfall (intensity/amounts) (More intensive rainfall.), land tenure (Lack of control of livestock grazing activities.), poverty / wealth, war and conflicts (Gullies appeared after civil war.)

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

Technical specifications (related to technical drawing):

For the plugging of the gully, a low cost and simple barrier was made from locally available fast sprouting species of trees; in this case live willow cuttings were used. In the gully a narrow section was selected, and cuttings (3-5 cm diameter, 1 m length) were placed in a line with 10 cm intervals in between. One third of the cuttings were planted in the gulley, and the rest were used to create a 'wave' wall of flexible branches, which was planted with local mulberry trees (1-1.5 cm diameter). The weaved branches have to be pushed down from the top to make the barrier suitably dense. The ends of the mulberry branches have to be stuck securely to the soil inside the gulley.

Location: Dorobi village. Khovaling / Khatlon / Tajikistan

Date: 2nd July, 2010

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: moderate

Main technical functions: control of concentrated runoff: impede / retard, stabilisation of soil (eg by tree roots against land slides)

Secondary technical functions: improvement of ground cover, increase of surface roughness, sediment retention / trapping, sediment harvesting

Aligned: -linear
Vegetative material: T : trees / shrubs
Vertical interval within rows / strips / blocks (m): 0.2

Trees/ shrubs species: mulberry

Retention/infiltration ditch/pit, sediment/sand trap
Vertical interval between structures (m): 3-5
Depth of ditches/pits/dams (m): 0.5
Width of ditches/pits/dams (m): 1.5
Length of ditches/pits/dams (m): 0.5

Construction material (wood): Willow and mulberry branches

Vegetation is used for stabilisation of structures.

Author:

Daler Domullojonov, 14, Giprozem street, Dushanbe, Tajikistan

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Tajik Somoni

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

4.5

Indicate average wage cost of hired labour per day:

5.50 $

4.3 Establishment activities

Activity Timing (season)
1. planting mulberry in willow wave structure spring
2. establishment of barriers in gully bed once in the beginning

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Planting mulberry Persons/day 1.0 25.0 25.0 100.0
Labour Establishment of barriers in gully Persons/day 1.0 25.0 25.0 100.0
Plant material Mulberry seedlings Pieces 20.0 1.0 20.0 100.0
Construction material Willow cuttings Pieces 20.0 1.0 20.0 100.0
Total costs for establishment of the Technology 90.0
Total costs for establishment of the Technology in USD 20.0
Comments:

Duration of establishment phase: 12 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Reinforce structure with additional seedlings when needed annually
2. establishment of additional barriers after filling existing barriers with sediments once per year in beginning of rainy season

4.6 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 Reinforce structure Persons/day 1.0 25.0 25.0 100.0
Labour Establishment of additional barriers Persons/day 1.0 25.0 25.0 100.0
Plant material Mulberry seedlings Pieces 20.0 1.0 20.0 100.0
Construction material Willow cuttings Pieces 20.0 1.0 20.0 100.0
Total costs for maintenance of the Technology 90.0
Total costs for maintenance of the Technology in USD 20.0
Comments:

The unit cost is for a gulley plug, 1.5 metre wide and around 1m in height.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The materials used to construct the gulley plug are locally available, and are therefore free of charge to the land user. The labour (or time in labour) is the most substantial cost, and this is directly proportional to the number of gulley plugs required to infill the entire eroded gulley. If there is a big sediment load in the surface water runoff it will back fill behind the gulley plugs rapidly and additional barriers will need to be established.

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:

Precipitation is concentrated during the autumn and spring, averaging 1100-1200mm

Agro-climatic zone
  • semi-arid

Thermal climate class: temperate. 3 months below 5 degrees, 7 months above 10 degrees

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.
Comments and further specifications on topography:

Altitudinal zone: 1257 m a.s.l.

Slopes on average: Average slope 12.6%, max slope 17.2%

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)
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 texture = loess soil

Soil fertility is low due to over use and lack of fallow time.

Soil drainage / infiltration is poor

Soil water storage capacity is low

5.4 Water availability and quality

Ground water table:

> 50 m

Availability of surface water:

poor/ none

Water quality (untreated):

good drinking water

Comments and further specifications on water quality and quantity:

Availability of surface water: In the area around the gulley the land is compacted.

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:
  • 10-50% of all income
Relative level of wealth:
  • poor
  • average
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

Population density: 10-50 persons/km2

Annual population growth: 1% - 2%; 2%

20% of the land users are average wealthy.
80% of the land users are poor.

5.7 Average area of land used 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:
  • leased

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

wood production

decreased
increased
Comments/ specify:

The trees can be harvested once the gulley is full of sediment.

production area

decreased
increased
Quantity before SLM:

1.5

Quantity after SLM:

1.6

Comments/ specify:

Gully filling can help create new areas of arable land.

Socio-cultural impacts

SLM/ land degradation knowledge

reduced
improved

Livelihood and human well-being

reduced
improved

Ecological impacts

Water cycle/ runoff

surface runoff

increased
decreased
Soil

soil cover

reduced
improved

soil loss

increased
decreased
Comments/ specify:

Sediments are trapped

Climate and disaster risk reduction

landslides/ debris flows

increased
decreased

6.2 Off-site impacts the Technology has shown

downstream flooding

increased
reduced

buffering/ filtering capacity

reduced
improved

damage on neighbours' fields

increased
reduced

damage on public/ private infrastructure

increased
reduced

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 increase or decrease How does the Technology cope with it?
annual temperature increase not known

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
local windstorm not known
Climatological disasters
How does the Technology cope with it?
drought not well
Hydrological disasters
How does the Technology cope with it?
general (river) flood not well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period not known
Comments:

As a living barrier it needs to grow, and therefore it is sensitive to drought conditions.

6.4 Cost-benefit analysis

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

neutral/ balanced

Long-term returns:

positive

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

neutral/ balanced

Long-term returns:

positive

6.5 Adoption of the Technology

  • > 50%
If available, quantify (no. of households and/ or area covered):

10 households in an area of 1.7 ha

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 91-100%
Comments:

100% of land user families have adopted the Technology without any external material support

10 land user families have adopted the Technology without any external material support

There is a little trend towards spontaneous adoption of the Technology

Comments on adoption trend: There is little trend towards (growing) spontaneous adoption of the technology.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
No training and additional skills are required.

How can they be sustained / enhanced? Broad promotion to other communities with similar climatic conditions and similar issues.
It is low cost option.
Easy to establish, with a low workload.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Gulley plugs are relatively easy to construct and have a low initial outlay.

How can they be sustained / enhanced? It could be further supported by the strong involvement of local authorities, through the organisation of cross visits, and disseminating ideas between farmers.
It is flexible as various varieties of local sprouting trees can be used to build the gulley plug.
It can prevent further erosion and expansion of the gulley. It can also increase the amount of land available for pasture activities.
Environmentally friendly

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?
The gulley plug is weak in the beginning as the mulberry trees become more established. It is more susceptible to the impact of heavy rainfall events and concentrated run off down the gulley. High levels of maintenance in the first initial few seasons.
The gulley plug becomes less effective as the gullies become wider and deeper. Fencing around the gulley.
The gulley plug has to be protected from livestock who will eat the vegetation.

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Welthungerhilfe project final narrative report (144-912) - 2010

Available from where? Costs?

Welthungerhilfe projects in Khatlon region, Temurmalik district

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