Local indigenous dyke for water harvesting [Lao People's Democratic Republic]
- Creation:
- Update:
- Compiler: kang phanvongsa
- Editors: Pasalath Khounsy, Bounthanom Bouahom, anousit namsena
- Reviewers: Nicole Harari, viengsavanh phimphachanhvongsod, Stephanie Jaquet, Alexandra Gavilano
technologies_2306 - Lao People's Democratic Republic
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Expand all Collapse all1. معلومات عامة
1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology
Key resource person(s)
land user:
Sengmany
Lao People's Democratic Republic
land user:
Sekhamphone Yangmao
Lao People's Democratic Republic
SLM specialist:
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Scaling-up SLM practices by smallholder farmers (IFAD)Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
National Agriculture and Forestry Research Institute (NAFRI) - Lao People's Democratic Republic1.3 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:
نعم
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?
لا
2. Description of the SLM Technology
2.1 Short description of the Technology
Definition of the Technology:
A Local Indigenous Weir to Harness Water
2.2 Detailed description of the Technology
Description:
Local villagers initiated the construction and use of communal weir with locally available materials such as wood and stones to create structure and stabilize the weir. Previously, the local people had constructed several irrigation weirs on a particular stream with each one being adjacent to an individual farm. However this arrangement created water use conflicts, particularly during dry season. Therefore people decided to group together in 2003 in order to build a communal weir and vowed to maintain it on an annual basis. This was a significant commitment as often it is difficult to find the necessary construction materials for the weir’s upkeep.
The main features and components of its framework should be prepared in the following manner: Firstly prior to beginning the weir’s construction one should gather rattan with length of 1-1.5 meters to tie the logs with each posts, as well as post with a diameter approximately 10 cm that should be cut to a length of 1.5 meters. The posts should then be sharpened at the end so that they can ideally be driven 50 cm into the ground, but this will depend on the conditions at the weir site. There should be a distance of 50 cm between each of the posts and these should be installed in two parallel rows with a space of 1 meter between the rows each rows width 1 meters and height 1 meter from the ground that cross the stream about 25 meters long.
Once this has been completed logs with diameter about 20 cm and a length of 4-5 meters should be slotted behind the rows posts and lay the another logs on the previous post until reach to the top of the post as the first layer. The second layer behind the logs should consist of small stones, soil, as well as branches and sticks. This procedure should be completed until the wall of horizontal logs has reached the height 1 meter of the top of the posts. Afterwards large stones should be placed as the top layer of the weir’s crest in order to strengthening the weir from flash flood. After that continue repeating the same process for the second row, driven the posts into the ground for 50 cm in front of the first row with distance of 1 meter and lower than first low for 50 cm, slotted behind the rows posts as the first layer. The second layer behind the logs (in front of the first row) consist small stones, soil, branch and sticks. Finally install large stones on the ground in front of the second row in order to strengthening and prevent leakages at bottom of the weir until reaching the required height. For instance, install the first row, then the second row is installed same as the first row in which the height of the second row is lower than the first row about 50 cm, and install large stones on ground of the third row to prevent leakages at bottom of the weir.
The main purpose of the weir is to provide an adequate water supply for agricultural activities in communal areas. Some households have also installed a dynamo (electric generator) with a production capacity of 1 Kwh. It should be noted that it is important to maintain the weir by regularly replacing the logs and adding more stones as required. One of the benefits of the weir is the ability to carry out agricultural activities in both the rainy and dry seasons. Furthermore water can be used for household gardening and the generation of electricity with the installation of a small dynamo where a channel with fast running water has been created. However, the weir does also have some drawbacks such as the significant numbers of logs that are required to firstly build and then maintain the weir annually. Therefore some land owners or land users may not choose this scheme due to these regular maintenance requirements with the need for logs which are declining in numbers and becoming increasingly difficult to source. At the same time this requirement may also affect forest resources and places time pressure on people to conduct the maintenance.
2.3 Photos of the Technology
2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment
بلد:
Lao People's Democratic Republic
Region/ State/ Province:
Tangnong village, Dakchaung district, Sekong province
Specify the spread of the Technology:
- applied at specific points/ concentrated on a small area
Comments:
There are 2 dykes on that stream
Map
×2.6 Date of implementation
Indicate year of implementation:
2003
If precise year is not known, indicate approximate date:
- 10-50 years ago
2.7 Introduction of the Technology
Specify how the Technology was introduced:
- as part of a traditional system (> 50 years)
3. Classification of the SLM Technology
3.1 Main purpose(s) of the Technology
- improve production
- reduce risk of disasters
- adapt to climate change/ extremes and its impacts
3.2 Current land use type(s) where the Technology is applied
الأراضي الزراعية
- Annual cropping
Annual cropping - Specify crops:
- cereals - rice (wetland)
- vegetables - other
Number of growing seasons per year:
- 1
حددها:
paddy rice is the main product
Waterways, waterbodies, wetlands
- Ponds, dams
Main products/ services:
paddy rice, electric generation
3.4 Water supply
Water supply for the land on which the Technology is applied:
- full irrigation
3.5 SLM group to which the Technology belongs
- water harvesting
- energy efficiency technologies
- ecosystem-based disaster risk reduction
3.6 SLM measures comprising the Technology
structural measures
- S5: Dams, pans, ponds
- S10: Energy saving measures
3.7 Main types of land degradation addressed by the Technology
chemical soil deterioration
- Cn: fertility decline and reduced organic matter content (not caused by erosion)
water degradation
- Ha: aridification
3.8 Prevention, reduction, or restoration of land degradation
Specify the goal of the Technology with regard to land degradation:
- reduce land degradation
Comments:
Sediments are leached from the mountain areas flow down to the stream ant therefrore the water contains organic matter that is beneficial for crops.
4. Technical specifications, implementation activities, inputs, and costs
4.1 Technical drawing of the Technology
Technical specifications (related to technical drawing):
The posts have length of about 1.5 m that are fixed into the ground water bottom at a deepness of around 50 cm.
There are two dike rows, each have width of 1 m and a length of approximattly 25 m (corresponding to the width of the stream)
The space between the two dikes is 1 m, the slope angle is 3-5 %
The beneficial area of these dikes is 10 ha of irrigated rice.
The construction material used consists of wooden post (diameters 10 cm and/a length 1.5 m), wood logs with of 20 cm diameter and length of 4-5 m, rattan used to thigten the wood logs with the post. Soil and small stone are put in the back of the wood logs and between the space of the two structures to limit water penetration. Then, also big stones are placed in front of the wood posts to stabilize the structure of the dikes.
After completion of the dike construction, a canal above the upper dike has to be digged to drain the accumulated water into the rice field.
Author:
Khampheng Bounyavong
Date:
12/05/2017
4.2 General information regarding the calculation of inputs and costs
Specify how costs and inputs were calculated:
- per Technology unit
Specify unit:
one dam
Specify dimensions of unit (if relevant):
width 1m, height 1m, depth 50 cm in the ground, length 25 m cross the steam
other/ national currency (specify):
Kip
If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:
8000,0
Indicate average wage cost of hired labour per day:
50 000 kip
4.3 Establishment activities
Activity | Timing (season) | |
---|---|---|
1. | Find dead wood logs | |
2. | Collect and prepare the rattan to tighten the wood | |
3. | Collect the stones and rocks | |
4. | Dyke installation |
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 | person | 48,0 | 50000,0 | 2400000,0 | 100,0 |
Equipment | Hummer | piece | 4,0 | 150000,0 | 600000,0 | 100,0 |
Equipment | Axes | piece | 10,0 | 100000,0 | 1000000,0 | 100,0 |
Equipment | Hoe | piece | 15,0 | 40000,0 | 600000,0 | 100,0 |
Equipment | Shovel | piece | 10,0 | 50000,0 | 500000,0 | 100,0 |
Equipment | Knife | piece | 10,0 | 25000,0 | 250000,0 | 100,0 |
Construction material | Wood logs | piece | 10,0 | 50000,0 | 500000,0 | 100,0 |
Construction material | Rattan | line | 200,0 | 20000,0 | 4000000,0 | 100,0 |
Construction material | Stones | m3 | 50,0 | 40000,0 | 2000000,0 | 100,0 |
Construction material | Wood post | piece | 10,0 | 10000,0 | 100000,0 | 100,0 |
Total costs for establishment of the Technology | 11950000,0 | |||||
Total costs for establishment of the Technology in USD | 1493,75 |
4.5 Maintenance/ recurrent activities
Activity | Timing/ frequency | |
---|---|---|
1. | Find the wood logs to repair the dikes | |
2. | Prepare the rattan to refix the logs with the posts | |
3. | Collect the stones to imrove the stabilize the dikes | |
4. | Repair the dike |
Comments:
Each year, people from the local community have to maintain and repair the dikes.
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 | Labor | person | 48,0 | 50000,0 | 2400000,0 | 100,0 |
Construction material | Wood logs | piece | 10,0 | 50000,0 | 500000,0 | 100,0 |
Construction material | Rattan | line | 200,0 | 10000,0 | 2000000,0 | 100,0 |
Construction material | Stones | m3 | 10,0 | 50000,0 | 500000,0 | 100,0 |
Construction material | Wood post | piece | 10,0 | 10000,0 | 100000,0 | 100,0 |
Total costs for maintenance of the Technology | 5500000,0 | |||||
Total costs for maintenance of the Technology in USD | 687,5 |
4.7 Most important factors affecting the costs
Describe the most determinate factors affecting the costs:
The labour for collecting the wood logs and the labour for the construction of the dike.
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
Specify average annual rainfall (if known), in mm:
870,00
Specifications/ comments on rainfall:
The driest month is January, with 14 mm of rainfall. In July, the precipitation reaches its peak. Heavy rain is between July-September. Total rain fall is about 3200 mm/year
Indicate the name of the reference meteorological station considered:
Natural resource office
Agro-climatic zone
- humid
The warmest month of the year is May, with an average temperature of 22.3 °C. With16.6 °C on average, January is the coldest month of the year.
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:
- convex situations
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):
- coarse/ light (sandy)
Soil texture (> 20 cm below surface):
- medium (loamy, silty)
Topsoil organic matter:
- medium (1-3%)
5.4 Water availability and quality
Ground water table:
< 5 m
Availability of surface water:
medium
Water quality (untreated):
for agricultural use only (irrigation)
Is water salinity a problem?
لا
Is flooding of the area occurring?
لا
5.5 Biodiversity
Species diversity:
- medium
Habitat diversity:
- medium
5.6 Characteristics of land users applying the Technology
Sedentary or nomadic:
- Sedentary
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:
- mechanized/ motorized
Gender:
- women
- men
Age of land users:
- youth
- middle-aged
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:
- communal/ village
- individual, not titled
Land use rights:
- individual
Water use rights:
- open access (unorganized)
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
crop quality
Quantity before SLM:
8 tons/ha
Quantity after SLM:
2 tons/ha
Comments/ specify:
Before gold mining company entered in the area the yield of rice raised to 8 tons/ha due to the aboundant irrigation water caused by the dike construction. But unfortunately actually (in 2017), due to gold excavating rice yield decreased to 2 tons/ha, only.
energy generation
Comments/ specify:
Some households also install dynamo ( electric generator ) with production capacity of 1 Kwh.
Water availability and quality
irrigation water availability
Comments/ specify:
Before, water for cultivation was insufficient especially during dry season as the stream water level was too low , after the weir construction the stream water level got high enough to fill the canal leading to the production area all-year round.
Socio-cultural impacts
conflict mitigation
Comments/ specify:
Before dyke construction the villagers tried to bring water to their fields by small individual canals during dry season. This caused competition and conflicts on scares water scarcity. After the communal wire construction the conflicts situation have been been improved.
Ecological impacts
Water cycle/ runoff
water quantity
Comments/ specify:
Without dikes, the stream water quantity was too low to produce enough yield mainly regardomg dry season cultivation. After weir construction the farmers let the water flow from the canal into the water reservoir which allows agricultural activities on a year-round basis.
Climate and disaster risk reduction
drought impacts
Comments/ specify:
Even during dry season (and drought events) the farmers bring enough the water to the fields.
6.2 Off-site impacts the Technology has shown
reliable and stable stream flows in dry season
Comments/ specify:
The weir stopped to some extent the natural water flow. This causes slower but still regular downstream water flow during dry season.
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 | moderately | |
seasonal temperature | dry season | decrease | well |
seasonal rainfall | wet/ rainy season | increase | moderately |
other gradual climate change | None | increase | well |
Climate-related extremes (disasters)
Meteorological disasters
How does the Technology cope with it? | |
---|---|
local hailstorm | not well |
Climatological disasters
How does the Technology cope with it? | |
---|---|
extreme winter conditions | not well |
Hydrological disasters
How does the Technology cope with it? | |
---|---|
flash flood | moderately |
Biological disasters
How does the Technology cope with it? | |
---|---|
epidemic diseases | moderately |
insect/ worm infestation | not well |
Other climate-related consequences
Other climate-related consequences
How does the Technology cope with it? | |
---|---|
extended growing period | not well |
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:
slightly positive
How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:
slightly positive
Long-term returns:
slightly negative
6.5 Adoption of the Technology
- 11-50%
Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
- 91-100%
6.6 التكيف
Has the Technology been modified recently to adapt to changing conditions?
لا
6.7 Strengths/ advantages/ opportunities of the Technology
Strengths/ advantages/ opportunities in the land user’s view |
---|
Inputs are economically beneficial. |
Provides a reliable water supply for agricultural activities. |
Electricity can be generated with a small dynamo. |
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view |
---|
Mitigates water use conflicts which could occur in the village. |
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 only possible to construct a temporary weir due to the low quality of locally available materials | |
A great deal of time needs to be invested in annual maintenance work. |
7. References and links
7.1 Methods/ sources of information
- field visits, field surveys
1 time
- interviews with land users
2 persons
When were the data compiled (in the field)?
11/05/2017
Links and modules
Expand all Collapse allLinks
No links
Modules
No modules