Lining irrigation canals [Mali]
- Creación:
- Actualización:
- Compilador: Dieter Nill
- Editor: –
- Revisores: Deborah Niggli, Alexandra Gavilano
Revêtement des canaux d’irrigation (French)
technologies_1651 - Mali
Visualizar secciones
Expandir todo Colapsar todos1. Información general
1.2 Detalles de contacto de las personas de referencia e instituciones involucradas en la evaluación y la documentación de la Tecnología
Especialista MST:
Traore Minamba
IICEM
Mali
Nombre del proyecto que financió la documentación/ evaluación de la Tecnología (si fuera relevante)
Manual of Good Practices in Small Scale Irrigation in the Sahel (GIZ )Nombre de la(s) institución(es) que facilitaron la documentación/ evaluación de la Tecnología (si fuera relevante)
Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH (GIZ) - Alemania1.3 Condiciones referidas al uso de datos documentados mediante WOCAT
El compilador y la/s persona(s) de referencia claves aceptan las condiciones acerca del uso de los datos documentados mediante WOCAT:
Sí
1.4 Declaración de la sostenibilidad de la Tecnología descrita
¿La Tecnología aquí descrita resulta problemática en relación a la degradación de la tierra, de tal forma que no puede considerársela una tecnología sostenible para el manejo de la tierra?
No
2. Descripción de la Tecnología MST
2.1 Breve descripción de la Tecnología
Definición de la Tecnología:
Lining canals is a powerful way to save irrigation water by minimising seepage losses, and to reduce pumping time and costs.
2.2 Descripción detallada de la Tecnología
Descripción:
The irrigation area’s main earthen canals have their inverts lined in concrete and their sides lined with solid cement blocks. Concrete support posts are set at intervals and capped in concrete. Each lined main canal should be no longer than two kilometres. The main canal’s turnouts into the secondary canals are built in cement and are equipped with gates that can be opened and closed as required.
Each turnout’s outflow area is protected by a rockfill structure that is built right up to the top of the canal wall to prevent the canal banks at the head of the secondary canals from becoming degraded.
Lining is mainly used to improve the efficiency of existing irrigation systems. Once the canal has been lined, yields increase by between 35% and 80%. This is because crops receive the water they need to ripen as and when it is required. Often, lining also makes it possible to extend the irrigated area. Pumping hours per hectare are considerably reduced (by 25% in the rainy season) because the canals ensure the correct distribution of irrigation water. Consequently, irrigation costs per tonne of produce drop due to the reduction in pumping hours and the costs of periodical maintenance and increases in yields.
Together with the growers, a memorandum of understanding was drawn up with IICEM and then signed by the mayor. The memorandum describes all the activities that form part of the collaboration between IICEM and the various beneficiaries. The works were carried out either in-company or constituted part of the highly labour-intensive work (HLIW).
a) Work delivered in-company (turnkey basis): Works are carried out in several stages: 1) Identifying the sites requiring lining. This involves locating the sites to develop and making contact with the NGOs that represent the project in the region, as well as regional directorates of rural engineering and economic operators working with the farming organisations in question. 2) The delimited sites chosen for development must undergo technical studies, which are entrusted to engineering consultancies recruited through an open tender process in accordance with the terms of reference for the studies to be conducted. 3) The technical feasibility studies comprise topographical, geotechnical, soil and environmental studies, as well as the creation of a development plan and quantification of materials required for the construction work. 4) Drawing up the invitation to tender (ITT) documents and communicating the tender process to businesses. In lieu of a ToR, an ITT is created by the project according to the requirements of the site. It is then published so that interested consultancies can put forward their bids. 5) Works are carried out under the control and supervision of the oversight office to ensure they adhere to professional standards.
b) Highly labour-intensive work: 1) The same as above. 2) Topographical surveys are carried out by IICEM specialists to calculate the calibration of the canals to ensure they are able to submerge plots over a large area. 3) After calibrating the schemes (energy dissipation basin and division box, main canal and secondary canal turnout, channel), a work plan is drawn up. This uses the measurements calculated to quantify construction material and equipment requirements. 4) Teams of (preferably local) builders are recruited to line the canals. The teams comprise master builders, reinforcing ironworkers, bricklayers and surveyors. 5) The materials and equipment required for each site are provided by an appropriate supplier recruited through a tendering process. 6) Provision of labour and farmer participation. Only the building contractors are paid for working on the project. Labour is supplied by the local community who are provided with lunch to maintain motivation and to prevent lost time caused by workers going off-site. 7) In villages where schemes are proposed, teams of shift workers from the local community are set up and trained in proper conduct for working on a canal lining project and in the keeping of a construction project log book.
Once the canal lining works are complete, IICEM provides a pump unit and subsidises the required fuel and consumables for one growing season. Training in how to run and maintain pump units is provided for the local beneficiaries tasked with their upkeep. Furthermore, training in the management and maintenance of irrigation schemes is delivered to the farming organisations’ steering committee.
The lifespan of a canal lining ranges from 10 to 20 years if small repairs are regularly undertaken. Ensuring linings are impermeable is of the utmost importance because water penetrating through micro-cracks as it flows through the network can lead to rapid and major water loss. It is therefore essential that producers can maintain installations and repair cracks.
The Sahel is a region where the population has always faced a high degree of climate variability, manifested both in terms of time (unexpected dry spells can occur during the rainy season) and in terms of space (rainfall can vary greatly from one area to another). The population is mainly composed of small farmers and livestock keepers.
Over the last two decades, the effects of climate change have exacerbated the already difficult conditions. Accord¬ing to projections made by climatologists, the Sahel will experience a rise in temperatures combined with highly variable rainfall and an increase in extreme weather events.
The Soil and Water conservation and rehabilitation techniques have helped people in the Sahel to manage their ecosystems more effectively and improve their productive land. As a result, communities are better prepared to cope with environmental changes (changes in the climate, land degradation, etc.) and the im¬pact of shocks, particularly droughts
2.3 Fotografías de la Tecnología
2.5 País/ región/ lugares donde la Tecnología fue aplicada y que se hallan comprendidos por esta evaluación
País:
Mali
Región/ Estado/ Provincia:
Mali
Especifique más el lugar :
Mopti, Timbuktu, Gao, Sikasso
Especifique la difusión de la Tecnología:
- distribuida parejamente sobre un área
Si la Tecnología se halla difundida homogéneamente a lo largo de un área, especifique el área que cubre (en km2):
12,0
Comentarios:
Total area covered by the SLM Technology is 12 km2.
Around 50 sites covering approximately 1200 hectares have had their canals lined
Map
×2.6 Fecha de la implementación
Si no se conoce el año preciso, indique la fecha aproximada:
- hace menos de 10 años (recientemente)
2.7 Introducción de la Tecnología
Especifique cómo se introdujo la Tecnología:
- mediante proyectos/ intervenciones externas
Comentarios (tipo de proyecto, etc.):
This kind of practice has been carried out by IICEM since 2009.
3. Clasificación de la Tecnología MST
3.1 Propósito(s) principal(es) de la Tecnología MST
- mejorar la producción
- conservar el ecosistema
3.2 Tipo(s) actuales de uso de la tierra donde se aplica la Tecnología
Mezcla de tipos de uso de tierras dentro de la misma unidad de tierras: :
Sí
Especifique el uso combinado de tierras (cultivos/ pastoreo/ árboles):
- Agropastoralismo (incluyendo cultivo-ganado integrados)
Tierras cultivadas
- Cosecha anual
Número de temporadas de cultivo por año:
- 1
Especifique:
Longest growing period in days: 120Longest growing period from month to month: August-November
Tierra de pastoreo
vías fluviales, masas de agua, humedales
- Líneas de drenaje, vías fluviales
Comentarios:
Major land use problems (compiler’s opinion): unequal distribution of irrigation water, ineffective irrigation systems (water loss)
Livestock density: 1-10 LU /km2
3.4 Provisión de agua
Provisión de agua para la tierra donde se aplica la Tecnología:
- mixta de secano – irrigada
3.5 Grupo MST al que pertenece la Tecnología
- pastoralismo y manejo de tierras de pastoreo
- Manejo de irrigación: (incl. provisión de agua, invernaderos)
- diversión y drenaje de agua
3.6 Medidas MST que componen la Tecnología
medidas estructurales
- S3: Acequias graduadas, canales, vías fluviales
3.7 Principales tipos de degradación del suelo encarados con la Tecnología
erosión de suelos por agua
- Wr: erosión de riberas
deterioro químico del suelo
- Cn: reducción de la fertilidad y contenido reducido de la materia orgánica del suelo (no ocasionados por la erosión)
degradación biológica
- Bc: reducción de la cobertura vegetal del suelo
degradación del agua
- Ha: aridificación
Comentarios:
Main causes of degradation: soil management (Unadapted landuse methods, reduced or abandoned fallow periods), crop management (annual, perennial, tree/shrub) (Neglect of fallow periods and crop rotation), over abstraction / excessive withdrawal of water (for irrigation, industry, etc.), droughts (due to heat waves), population pressure (rapidly growing population increasing pressure on land), land tenure (insecure access to land and collectively managed communal land), poverty / wealth (very poor population)
Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (deforestation through overgrazing and fire wood collection), over-exploitation of vegetation for domestic use (firewood collection), overgrazing (cattle, sheep and goats), change in temperature (Climate change: heat waves), change of seasonal rainfall (more variable onset of rain), Heavy / extreme rainfall (intensity/amounts) (more variable and intensive rains), wind storms / dust storms (frequent storms), floods (due to intensive rain storms), labour availability (some migration of men to nearby cities), education, access to knowledge and support services (high level of illiteracy)
3.8 Prevención, reducción o restauración de la degradación del suelo
Especifique la meta de la Tecnología con relación a la degradación de la tierra:
- prevenir la degradación del suelo
- reducir la degradación del suelo
4. Especificaciones técnicas, actividades de implementación, insumos y costos
4.1 Dibujo técnico de la Tecnología
Especificaciones técnicas (relacionadas al dibujo técnico):
The irrigation area’s main earthen canals have their inverts lined in concrete and their sides lined with solid cement blocks. Concrete support posts are set at intervals and capped in concrete. Each lined main canal should be no longer than two kilometres. The main canal’s turnouts into the secondary canals are built in cement and are equipped with gates that can be opened and closed as required. Each turnout’s outflow area is protected by a rockfill structure that is built right up to the top of the canal wall to prevent the canal banks at the head of the secondary canals from becoming degraded.
Technical knowledge required for field staff / advisors: high
Technical knowledge required for land users: low
Main technical functions: water harvesting / increase water supply, water spreading
Autor:
Minamba Traore, IICEM
4.2 Información general sobre el cálculo de insumos y costos
otra / moneda nacional (especifique):
CFA Franc
Si fuera relevante, indique la tasa de cambio de dólares americanos a la moneda local (ej. 1 U$ = 79.9 Reales Brasileros): 1 U$ =:
512,0
4.3 Actividades de establecimiento
Actividad | Momento (estación) | |
---|---|---|
1. | Identifying the sites requiring lining | |
2. | Launching the invitation to tender for the technical studies / Undertaking topographical surveys to calibrate schemes | |
3. | Performing the technical studies / Quantifying building material requirements | |
4. | Drawing up the invitation to tender (ITT) documents and communicating the tender process to businesses / Recruitment of masons, bricklayers and reinforcing ironworkers | |
5. | Delivery of works under the supervision of the oversight office / Invitation to tender for the provision of materials and equipment | |
6. | Provision of labour and farmer participation | |
7. | Training workers from the local community in building site conduct |
4.5 Actividades de establecimiento/ recurrentes
Actividad | Momento/ frequencia | |
---|---|---|
1. | small repairs are regularly undertaken |
4.7 Factores más determinantes que afectan los costos:
Describa los factores más determinantes que afectan los costos:
Around 50 sites covering approximately 1,200 hectares have had their canals lined. Total costs: 1,587,865.50 US Dollar
5. Entorno natural y humano
5.1 Clima
Lluvia anual
- < 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
Zona agroclimática
- semi-árida
5.2 Topografía
Pendientes en promedio:
- plana (0-2 %)
- ligera (3-5%)
- moderada (6-10%)
- ondulada (11-15%)
- accidentada (16-30%)
- empinada (31-60%)
- muy empinada (>60%)
Formaciones telúricas:
- meseta/ planicies
- cordilleras
- laderas montañosas
- laderas de cerro
- pies de monte
- fondo del valle
Zona altitudinal:
- 0-100 m s.n.m.
- 101-500 m s.n.m.
- 501-1,000 m s.n.m
- 1,001-1,500 m s.n.m
- 1,501-2,000 m s.n.m
- 2,001-2,500 m s.n.m
- 2,501-3,000 m s.n.m
- 3,001-4,000 m s.n.m
- > 4,000 m s.n.m
5.3 Suelos
Profundidad promedio del suelo:
- muy superficial (0-20 cm)
- superficial (21-50 cm)
- moderadamente profunda (51-80 cm)
- profunda (81-120 cm)
- muy profunda (>120 cm)
Textura del suelo (capa arable):
- mediana (limosa)
- fina/ pesada (arcilla)
Materia orgánica de capa arable:
- media (1-3%)
- baja (<1%)
5.4 Disponibilidad y calidad de agua
Agua subterránea:
5-50 m
Disponibilidad de aguas superficiales:
mediana
Calidad de agua (sin tratar):
solo para uso agrícola (irrigación)
5.5 Biodiversidad
Diversidad de especies:
- mediana
5.6 Las características de los usuarios de la tierra que aplican la Tecnología
Sedentario o nómada:
- Sedentario
Orientación del mercado del sistema de producción:
- mixta (subsistencia/ comercial)
Ingresos no agrarios:
- 10-50% de todo el ingreso
Nivel relativo de riqueza:
- pobre
- promedio
Nivel de mecanización:
- trabajo manual
Género:
- hombres
Indique otras características relevantes de los usuarios de las tierras:
Population density: < 10 persons/km2
Annual population growth: 2% - 3%
10% of the land users are rich.
50% of the land users are average wealthy.
30% of the land users are poor.
10% of the land users are poor.
5.7 Área promedio de la tierra usada por usuarios de tierra que aplican la Tecnología
- < 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
¿Esto se considera de pequeña, mediana o gran escala (refiriéndose al contexto local)?
- pequeña escala
5.8 Tenencia de tierra, uso de tierra y derechos de uso de agua
Comentarios:
The irrigated land is allocated by the chief
5.9 Acceso a servicios e infraestructura
salud:
- pobre
- moderado
- bueno
educación:
- pobre
- moderado
- bueno
asistencia técnica:
- pobre
- moderado
- bueno
empleo (ej. fuera de la granja):
- pobre
- moderado
- bueno
mercados:
- pobre
- moderado
- bueno
energía:
- pobre
- moderado
- bueno
caminos y transporte:
- pobre
- moderado
- bueno
agua potable y saneamiento:
- pobre
- moderado
- bueno
servicios financieros:
- pobre
- moderado
- bueno
6. Impactos y comentarios para concluir
6.1 Impactos in situ demostrados por la Tecnología
Impactos socioeconómicos
Producción
producción de cultivo
riesgo de fracaso de producción
área de producción
Ingreso y costos
carga de trabajo
Impactos socioculturales
seguridad alimentaria/ autosuficiencia
mitigación de conflicto
Impactos ecológicos
Ciclo de agua/ escurrimiento de sedimento
cantidad de agua
cosecha/ recolección de agua
6.2 Impactos fuera del sitio demostrados por la Tecnología
corriente confiable y estable fluye en estación seca
contaminación de aguas subterráneas/ de ríos
sedimentos transportados por el viento
6.3 Exposición y sensibilidad de la Tecnología al cambio climático gradual y a extremos relacionados al clima/ desastres (desde la percepción de los usuarios de tierras)
Cambio climático gradual
Cambio climático gradual
Estación | Incremento o reducción | ¿Cómo es que la tecnología soporta esto? | |
---|---|---|---|
temperatura anual | incrementó | bien |
Extremos (desastres) relacionados al clima
Desastres climatológicos:
¿Cómo es que la tecnología soporta esto? | |
---|---|
tormenta de lluvia local | no muy bien |
tormenta de viento | bien |
Desastres climatológicos
¿Cómo es que la tecnología soporta esto? | |
---|---|
sequía | bien |
Desastres hidrológicos
¿Cómo es que la tecnología soporta esto? | |
---|---|
inundación general (río) | no muy bien |
Otras consecuencias relacionadas al clima
Otras consecuencias relacionadas al clima
¿Cómo es que la tecnología soporta esto? | |
---|---|
periodo reducido de crecimiento | no se sabe |
6.4 Análisis costo-beneficio
¿Cómo se comparan los beneficios con los costos de establecimiento (desde la perspectiva de los usuarios de tierra)?
Ingresos a corto plazo:
ligeramente negativo
Ingresos a largo plazo:
ligeramente positivo
¿Cómo se comparan los beneficios con los costos de mantenimiento/ recurrentes (desde la perspectiva de los usuarios de tierra)?
Ingresos a corto plazo:
ligeramente positivo
Ingresos a largo plazo:
muy positivo
6.5 Adopción de la Tecnología
Comentarios:
Comments on spontaneous adoption: Lining of canals is an investment which is generally only feasible with external assistance.
There is no trend towards spontaneous adoption of the Technology
Comments on adoption trend: Irrigation system canals in Mopti, Timbuktu, Gao and Sikasso have been lined.
Around 50 sites covering approximately 1,200 hectares have had their canals lined. This kind of practice has been carried out by IICEM since 2009.
6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología
Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave |
---|
Lining canals is a powerful way to save irrigation water by minimising seepage losses. |
Pumping time and costs are also greatly reduced through the speedy distribution of irrigation water supplies, and reducing the use of motorised pumps lowers maintenance costs. |
Yields increase by between 35% and 80%. Often, lining also makes it possible to extend the irrigated area. |
Training in how to run and maintain pump units is provided for the local beneficiaries tasked with their upkeep. Furthermore, training in the management and maintenance of irrigation schemes is delivered to the farming organisations’ steering committee |
The lifespan of a canal lining ranges from 10 to 20 years |
7. Referencias y vínculos
7.1 Métodos/ fuentes de información
- visitas de campo, encuestas de campo
- entrevistas con usuarios de tierras
¿Cuándo se compilaron los datos (en el campo)?
01/07/2012
7.2 Vínculos a las publicaciones disponibles
Título, autor, año, ISBN:
Manual of Good Practices in Small Scale Irrigation in the Sahel. Experiences from Mali. Published by GIZ in 2014.
¿Dónde se halla disponible? ¿Costo?
http://star-www.giz.de/starweb/giz/pub/servlet.starweb
Título, autor, año, ISBN:
www.iicem.net
Vínculos y módulos
Expandir todo Colapsar todosVínculos
No hay vínculos
Módulos
No se hallaron módulos