Technologies

Gravity type inverted tyre structure [South Africa]

Swaartekrag tipe omgedopte bande struktuur (Afrikaans)

technologies_1374 - South Africa

Completeness: 65%

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:

Du Toit Boeta P.

Marico Bushveld Soil Conservation Committee, South Africa

South Africa

SLM specialist:

Meiring C. H.

Marico Bushveld Soil Conservation Committee, South Africa

South Africa

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

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Stabilising of gully erosion by means of gravity type inverted tyre structures filled with stone.

2.2 Detailed description of the Technology

Description:

Gravity type inverted tyre structure is bound together with wire and filled with stone.
The valley floor gully head drop is protected to prevent further erosion. Survey planning and design are important for the construction of the structure.
Maintenance includes prevention of leakage alongside the structure. The walls to prevent the erosion of soil are filled in. Ensure that the top layer stones are not washed away.
The structure is situated in a semi-arid area which is highly degraded through overgrazing.
Due to the location of the structure, further erosion was stopped that would have endangered some of the homesteads.

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:

South Africa

Region/ State/ Province:

North West Province

Further specification of location:

Marico District

Specify the spread of the Technology:
  • evenly spread over an area
If the Technology is evenly spread over an area, specify area covered (in km2):

12.0

Comments:

Total area covered by the SLM Technology is 12 km2.

Same technology was also applied in the Molatedi tribal village (70 km away in the same catchment area)

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.):

Developed by technician department Resource Conservation and farmer from local conservation committee.

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

Grazing land

Grazing land

Comments:

Major land use problems (compiler’s opinion): Lack of landuse planning. Overgrazing. Overpopulation.

Major land use problems (land users’ perception): Lack of grazing land, frequent occurrence of droughts.

Constraints of infrastructure network (roads, railways, pipe lines, power lines): Not planning for access roads in the village

Number of growing seasons per year: 1
Longest growing period in days: 240; Longest growing period from month to month: Sep - Apr

3.5 SLM group to which the Technology belongs

  • cross-slope measure

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S1: Terraces

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wg: gully erosion/ gullying
Comments:

Secondary types of degradation addressed: Wt: loss of topsoil / surface erosion

Main causes of degradation: overgrazing, droughts, education, access to knowledge and support services (Lack of knowledge - Lack of training & awareness)

Secondary causes of degradation: over-exploitation of vegetation for domestic use, other human induced causes (specify) (Agricultural causes - Lack of extension and planning), land tenure (Land subdivision - Only if someone own land (commercial farmers)), poverty / wealth (Lack of employment), Lack of enforcement of legislat./authority (Regarding natural resources)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • prevent land degradation
  • reduce land degradation
Comments:

Secondary goals: prevention of land degradation

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

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

further downstream another tyre construction trapping the silt, behind the structure silting up and vegetation is well growing

North West

Date: April 1999

Technical knowledge required for field staff / advisors: high

Technical knowledge required for land users: moderate

Main technical functions: control of dispersed runoff: impede / retard

Structural measure: Gully head drop structure

Construction material (earth): wire iron posts, plastic material, geotextilemembranes (bidim-kaymat) -water permeable soil exclude

Lateral gradient along the structure: 50%

Author:

Mirjam Staehli, Switzerland

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Rand

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

6.0

Indicate average wage cost of hired labour per day:

1.50

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 Labour ha 1.0 9400.0 9400.0
Equipment Tools ha 1.0 600.0 600.0
Equipment Tyre averting tool machine ha 1.0 100.0 100.0
Construction material Geotextile membrane ha 1.0 2000.0 2000.0
Construction material Wire 2mm (rolls a 50kg) ha 1.0 330.0 330.0
Construction material Fully galvanised iron ha 1.0 50.0 50.0
Total costs for establishment of the Technology 12480.0
Total costs for establishment of the Technology in USD 2080.0
Comments:

Duration of establishment phase: 0 month(s)

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

Comments:

The complete structure.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Labour - very low productivity. Transportation of tyres. Tying wire must be cut economically according to need otherwise huge waste take place.

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:

Thunderstorms, heavy rainfall

Agro-climatic zone
  • semi-arid

Summer rainfall

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.
Indicate if the Technology is specifically applied in:
  • concave situations
Comments and further specifications on topography:

Soil fertility is low

Soil drainage / infiltration is good

Soil water storage capacity is medium

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%)

5.6 Characteristics of land users applying the Technology

Off-farm income:
  • > 50% of all income
Relative level of wealth:
  • poor
Indicate other relevant characteristics of the land users:

Population density: 100-200 persons/km2

Annual population growth: 3% - 4%

and own 100% of the land (Communal land belongs to the tribe).

Off-farm income specification: State pensions- head of family work elsewhere.

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

Land ownership:
  • communal/ village
Land use rights:
  • open access (unorganized)

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Income and costs

diversity of income sources

decreased
increased
Comments/ specify:

short term job creation

Socio-cultural impacts

community institutions

weakened
strengthened

SLM/ land degradation knowledge

reduced
improved

Ecological impacts

Soil

soil loss

increased
decreased

6.2 Off-site impacts the Technology has shown

downstream flooding

increased
reduced

downstream siltation

increased
decreased

spending on consumer goods in shops in area

decreased
increased

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:

positive

Long-term returns:

positive

6.5 Adoption of the Technology

  • 11-50%
If available, quantify (no. of households and/ or area covered):

20 percent of the area

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 0-10%
Comments:

100% of land user families have adopted the Technology with external material support

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

Comments on acceptance with external material support: estimates

There is no trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Labour intensive, job creation
Received training
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Low cost material
Labour intensive can be utilized without machinery
Mostly unskilled labour can be used.

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?
Storm water walls are in the way of motor vehicles, travelling in the village Plan roads properly - construct alternative road around wall.
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Costly if manual labour is unproductive Maintain high productivity. Train workers, work smart, contract work
Transport cost of tyres is a big factor. Utilize tyres from nearby areas. Utilizes big transport trucks with big loading capacity.
Need machine to invert tyres Tool well and practically constructed - operators trained.
Must technically be well planned and constructed. Use skilled technician for planning and to assist workers during construction.

7. References and links

7.1 Methods/ sources of information

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