Earth and stone bunds for erosion control in a hilly area. (Jose D. Rondal (Quezon City, Philippines))

Stone bunds and small basins (Philippines)

Pamugong sa yuta (Cebuano)

Description

Piling of stones and rocks along the contour to control run-off and soil erosion. It is also about the creation of small basins by removing stones and using them as barriers.

This is a low-cost erosion control technology by piling stones/rocks along the contour. The spacing of the piles depends on the slope and the availability/abundance of surface rocks. The stone bunds, usually 0.4 meter wide is intended to slow down run-off and catch/impound soil that moves downslope, etiher by water or by gravity. The technology is also about the creation of small basins by removing rocks and using them as barrier. In these small basins, water is impounded and allow to infiltrate. Soil carried with the run-off is deposited in these basins for the raising of high value crops. The technology is most especially applicable in areas where limestone and other rock outcrops and where the soil is commonly shallow and skeletal. With time, natural terraces can form. Limestone/rock outcrops are also used in the construction of check dams along small waterways. These check dams will result in the formation of flat-bottom valleys where transplanted rice is usually grown. Series of check dams will form terraces along valley floor in the long run.

Location

Location: Siquijor, Cebu, Bohol, Negros Oriental, Philippines

No. of Technology sites analysed:

Geo-reference of selected sites
  • 124.3207, 10.1444

Spread of the Technology: evenly spread over an area (31.0 km²)

In a permanently protected area?:

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

Type of introduction
Stone walls/small basin (Jose D. Rondal (Quezon City, Philippines))
Construction of check dam along small waterway. (Lorenzo Co)

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

  • Cropland
    • Annual cropping: cereals - maize, vegetables - root vegetables (carrots, onions, beet, other)
    Number of growing seasons per year: 2

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
  • water degradation - Ha: aridification
SLM group
  • cross-slope measure
SLM measures
  • structural measures - S2: Bunds, banks

Technical drawing

Technical specifications
Construction of stone bunds along the contour for run-off and erosion control
Date: 8-22-2002

Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: moderate
Main technical functions: control of concentrated runoff: retain / trap
Secondary technical functions: reduction of slope length, increase / maintain water stored in soil
Author: Lorenzo Co

Establishment and maintenance: activities, inputs and costs

Calculation of inputs and costs
  • Costs are calculated:
  • Currency used for cost calculation: Philippine peso
  • Exchange rate (to USD): 1 USD = 50.0 Philippine peso
  • Average wage cost of hired labour per day: 4.00
Most important factors affecting the costs
Labor for the removal and collection of stones for piling.
Establishment activities
n.a.
Establishment inputs and costs
Specify input Unit Quantity Costs per Unit (Philippine peso) Total costs per input (Philippine peso) % of costs borne by land users
Labour
labour ha 1.0 1000.0 1000.0 100.0
Equipment
tools ha 1.0 20.0 20.0 100.0
Total costs for establishment of the Technology 1'020.0
Total costs for establishment of the Technology in USD 20.4
Maintenance activities
n.a.
Maintenance inputs and costs
Specify input Unit Quantity Costs per Unit (Philippine peso) Total costs per input (Philippine peso) % of costs borne by land users
Labour
labour ha 1.0 40.0 40.0 100.0
Total costs for maintenance of the Technology 40.0
Total costs for maintenance of the Technology in USD 0.8

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
Thermal climate class: tropics
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
increased


from nothing to something

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


area occupied by stone wall

land management
hindered
simplified


stone wall is also on obstruction

farm income
decreased
increased


from nothing to something

Socio-cultural impacts
conflict mitigation
worsened
improved

Ecological impacts
soil moisture
decreased
increased


Better infiltration

soil cover
reduced
improved


Better crop growth

soil loss
increased
decreased


Almost zero soil loss

Soil fertility
decreased
increased


Build-up of nutrients

Off-site impacts
downstream flooding (undesired)
increased
reduced

groundwater/ river pollution
increased
reduced

Cost-benefit analysis

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

Long-term returns
very negative
very positive

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

Long-term returns
very negative
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
  • Permanent
  • Clears the land for cultivation
Strengths: compiler’s or other key resource person’s view
  • Once established, it becomes permanent
  • Very effective in trapping sediment
Weaknesses/ disadvantages/ risks: land user's viewhow to overcome
  • Sancturies for pests Cleanliness of the surroundings
  • Laborious during establishment labor sharing
Weaknesses/ disadvantages/ risks: compiler’s or other key resource person’s viewhow to overcome
  • Stone wall serve as sanctuary for pests like rats and snakes Cleanliness of the surroundings
  • Stone wall can be an obstruction in cultivation and mobility

References

Compiler
  • Philippine Overview of Conservation Approaches and Technologies
Editors
Reviewer
  • Deborah Niggli
  • Alexandra Gavilano
Date of documentation: March 16, 2011
Last update: June 14, 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