1.2 Detalles de contacto de las personas de referencia e instituciones involucradas en la evaluación y la documentación de la Tecnología

Nombre del proyecto que financió la documentación/ evaluación de la Tecnología (si fuera relevante)

Good Practices in Soil and Water Conservation - A contribution to adaptation and farmers ́ resilience towards climate change 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) - Alemania

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

¿Cuándo se compilaron los datos (en el campo)?

01/07/2012

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

2.1 Breve descripción de la Tecnología

Definición de la Tecnología:

Permeable rock dikes are erosion control structures to slow down runoff

2.2 Descripción detallada de la Tecnología

Descripción:

Permeable rock dikes are erosion control structures built along the natural contour of the land and designed to slow down runoff. They are built between 30 and 50 cm high and twice or three times as wide as they are high. They are made with different-sized stones and rocks, and the crest of the dike is horizontal. There are two main types of permeable rock dike: those without a filter layer, which are suitable for flat land with no gully erosion and those with a filter layer suited to land with heavy runoff.

Because of the way it is constructed, it dissipates the erosive force of the water. Sediment builds up behind it, resulting in the formation of terraces. It also increases the infiltration of surface water into the soil. The retention of water and fertile sediment by the dikes facilitates the development of natural vegetation along the structure. Grass and bush seeds are trapped by the dikes, favouring the spontaneous growth of natural vegetation, which contributes to restoring biodiversity and provides a habitat for wildlife. Good tree and grass cover developed along the dikes contributes to lowering soil temperature and reducing wind erosion along the entire length of the structure.
The reduction in runoff downstream of the dikes contributes to reducing alluvial deposits in the valleys further downstream. Watershed development with permeable rock dikes reduces siltation and gully erosion.
Permeable rock dikes are designed for use on cropland, but can also be used on forest/rangeland. They are recommended for ecological units with gravely and sandy-clayey soils and pediments. They can also be used to fill in small rills.
Studies conducted in the PATECORE area show that plots with permeable rock dikes averaged sorghum yields of 795 kg compared with 576 kg on control plots, which means that yields were 38% higher on improved plots. The production of straw for livestock increases in the same proportion as grain output.

With some upkeep, permeable rock dikes last at least 20 years. Before the rainy season starts, any stones dislodged by animals must be replaced. During the rainy season, the water can wear gaps in the dikes, which must be repaired immediately. The stability of the dikes can be reinforced by active revegetation (by sowing grass or planting trees). Without direct sowing, natural vegetation develops along the dikes after several years.

From the point of view of climate change adaptation, permeable rock dikes mitigate the effects of variations in rainfall. They are appropriate in wet period with heavy rain and violent downpours: permeable rock dikes constructed on the upper edge of the plot as a protective measure and a means of improving infiltration, protect land at risk from erosion. They are also appropriate during dry periods as they stop or slow down the flow of water. Permeable rock dikes improve infiltration and therefore increase and prolong the availability of water for crops. The permeable rock dike differs from the contour stone bund in that it is bigger in size, is constructed with various layers of stones and is designed to control stronger water flow. For this reason, such dikes are often constructed up-stream of stone bunds to dissipate the force of the water flowing from the plateaux and slopes.

2.3 Fotografías de la Tecnología

2.5 País/ región/ lugares donde la Tecnología fue aplicada y que se hallan comprendidos por esta evaluación

2.6 Fecha de la implementación

Si no se conoce el año preciso, indique la fecha aproximada:

• 10-50 años atrás

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• mediante proyectos/ intervenciones externas

Comentarios (tipo de proyecto, etc.):

developed, implemented and disseminated as part of projects and programmes undertaken from the 1980s onwards to combat desertification and improve natural resource management. Implemented by GIZ (German Federal Enterprise for International Cooperation), and PATECORE (project for land development and resource conservation in Plateau Central)

3.1 Propósito(s) principal(es) de la Tecnología MST

• reducir, prevenir, restaurar la degradación del suelo

3.2 Tipo(s) actuales de uso de la tierra donde se aplica la Tecnología

Comentarios:

Major land use problems (compiler’s opinion): surface runoff, soil erosion by water and wind, fertility decline
Constraints of common grazing land
Constraints of forested government-owned land or commons

3.3 Información adicional sobre el uso de tierras

Número de temporadas de cultivo por año:

• 1

Especifique:

Longest growing period in days: 120, Longest growing period from month to month: August to October

3.4 Grupo MST al que pertenece la Tecnología

• medida de pendiente transversal

3.6 Medidas MST que componen la Tecnología

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

Main causes of degradation: crop management (annual, perennial, tree/shrub) (Unadapted landuse methods, reduced or abandoned fallow periods), floods, droughts, population pressure (rapidly growing population increasing pressure on land), land tenure (insecure access to land)

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:

• reducir la degradación del suelo
• restaurar/ rehabilitar tierra severamente degradada

4.1 Dibujo técnico de la Tecnología

4.2 Especificaciones técnicas/ explicaciones del dibujo técnico

Permeable rock dikes are built between 30 and 50 cm high and twice or three times as wide as they are high. They are made with different-sized stones and rocks, and the crest of the dike is horizontal. There are two main types of permeable rock dike: those without a filter layer, which are suitable for flat land with no gully erosion and those with a filter layer suited to land with heavy runoff.

Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: low
Main technical functions: control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, reduction of slope angle, improvement of ground cover, increase in nutrient availability (supply, recycling,…), increase of infiltration, increase / maintain water stored in soil, water harvesting / increase water supply, sediment retention / trapping, sediment harvesting
Secondary technical functions: stabilisation of soil (eg by tree roots against land slides), increase in organic matter, increase of groundwater level / recharge of groundwater, reduction in wind speed, promotion of vegetation species and varieties (quality, eg palatable fodder)

Bund/ bank: graded
Height of bunds/banks/others (m): 0.3-0.5
Width of bunds/banks/others (m): 1.5

4.4 Actividades de establecimiento

	Actividad	Tipo de medida	Momento
1.	levelling and marking out the contour line	Estructurales
2.	collecting stones and loading them onto carts	Estructurales
3.	transporting the stones by cart	Estructurales
4.	building the dikes	Estructurales
5.	applying manure	Estructurales

4.6 Actividades de establecimiento/ recurrentes

	Actividad	Tipo de medida	Momento/ frequencia
1.	Before the rainy season starts, any stones dislodged by animals must be replaced.	Estructurales
2.	During the rainy season, the water can wear gaps in the dikes, which must be repaired immediately.	Estructurales

4.7 Costos e insumos necesarios para actividades de mantenimiento/ recurrentes (por año)

Comentarios:

Machinery/ tools: pickaxes, shovels, wheelbarrows, water-tube level, etc.

4.8 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

The exact cost of constructing permeable rock dikes per hectare depends on the distance of the site from the quarry, the inclination of the terrain, which determines the spacing between the dikes, and the actual amount of stones transported in each lorryload or cartload. Supply of quarry rock/stones: 48 m3 for 200 m of dike.
Labour: 60 man-days per ha
• levelling and marking out the contour line: 1 man-day
• collecting stones and loading them onto carts:
20 man-days
• transporting the stones by cart: 20 man-days
• building the dikes: 19 man-days
• applying manure.
Transportation by cart:
• 20 cartloads of stones
• 20 cartloads of manure (if used).
Transportation by lorry:
• 11 lorryloads (skip loader – 4.5 m3 per load).
Other costs:
• equipment (pickaxes, shovels, wheelbarrows, water-tube level, etc.).

5.1 Clima

5.2 Topografía

5.3 Suelos

5.4 Disponibilidad y calidad de agua

5.5 Biodiversidad

5.6 Las características de los usuarios de la tierra que aplican la Tecnología

Indique otras características relevantes de los usuarios de las tierras:

Population density: 10-50 persons/km2
Annual population growth: 3% - 4% (mostly poor households below poverty line).
Off-farm income specification: men migrate temporarily or permanently to cities for off-farm income

5.7 Área promedio de la tierra que pertenece a o es arrendada por usuarios de tierra que aplican la Tecnología

5.8 Tenencia de tierra, uso de tierra y derechos de uso de agua

Tenencia de tierra:

• estado

Derechos de uso de tierra:

• comunitarios (organizado)

Derechos de uso de agua:

• comunitarios (organizado)

Comentarios:

traditional land use rights on fields, communal land on pasture and forest land

5.9 Acceso a servicios e infraestructura

6.1 Impactos in situ demostrados por la Tecnología

Impactos socioeconómicos

Producción

Ingreso y costos

Impactos socioculturales

Impactos ecológicos

Ciclo de agua/ escurrimiento de sedimento

Suelo

Biodiversidad: vegetación, animales

Reducción de riesgos de desastres y riesgos climáticos

6.2 Impactos fuera del sitio demostrados por la Tecnología

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	tipo de cambios climáticos/ climas extremos	¿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	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	bien

6.4 Análisis costo-beneficio

¿Cómo se comparan los beneficios con los costos de establecimiento (desde la perspectiva de los usuarios de tierra)?

¿Cómo se comparan los beneficios con los costos de mantenimiento/ recurrentes (desde la perspectiva de los usuarios de tierra)?

6.5 Adopción de la Tecnología

Comentarios:

There is a little trend towards spontaneous adoption of the Technology
The technique’s potential for replication depends on the type of terrain and the availability of a supply of stones within a reasonable distance. The technique is very effective as a flood control measure and is relatively easy to learn. Farmers are able to implement the technique themselves after two days’ training. This technique can only be implemented with highly motivated groups and villages, with strong working and mobilisation capacities.

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave
The retention of water and fertile sediment by the dikes facilitates the development of natural vegetation along the structure. Grass and bush seeds are trapped by the dikes, favouring the spontaneous growth of natural vegetation, which contributes to restoring biodiversity and provides a habitat for wildlife.
Studies conducted in the PATECORE area show that plots with permeable rock dikes averaged sorghum yields of 795 kg compared with 576 kg on control plots, which means that yields were 38% higher on improved plots. The production of straw for livestock increases in the same proportion as grain output.
The reduction in runoff downstream of the dikes contributes to reducing alluvial deposits in the valleys further downstream. Watershed development with permeable rock dikes reduces siltation and gully erosion.
The technique is very effective as a flood control measure and is relatively easy to learn. Farmers are able to implement the technique themselves after two days’ training.
With some upkeep, permeable rock dikes last at least 20 years.

6.8 Debilidades/ desventajas/ riesgos de la Tecnología y formas de sobreponerse a ellos

Debilidades/ desventajas/ riesgos desde la perspectiva del compilador o de otra persona de referencia clave	¿Cómo sobreponerse a ellas?
Permeable rock dikes are not as effective as contour stone bunds for the purpose of reforestation. This is because in the case of contour stone bunds, more linear metres are required per hectare than in the case of permeable rock dikes

7.1 Métodos/ fuentes de información

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

Good Practices in Soil and Water Conservation. A contribution to adaptation and farmers´ resilience towards climate change in the Sahel. Published by GIZ in 2012.

¿Dónde se halla disponible? ¿Costo?

http://agriwaterpedia.info/wiki/Main_Page