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

Nombre de la(s) institución(es) que facilitaron la documentación/ evaluación de la Tecnología (si fuera relevante)

Mekelle University (Mekelle University) - Etiopía

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

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

11/11/2012

El compilador y la/s persona(s) de referencia claves aceptan las condiciones acerca del uso de los datos documentados mediante WOCAT:

Sí

2.1 Breve descripción de la Tecnología

Definición de la Tecnología:

It is a raised wall constructed across a stream/gully using stone, concrete and/or gabion for dual purpose, namely, to pond/store the stream flow behind it for irrigation purpose while at the same time reducing the runoff velocity and enhancing gully rehabilitation.

2.2 Descripción detallada de la Tecnología

Descripción:

A check dam pond is a raised wall constructed across a gully from stone, concrete and/or gabion to store water behind it for irrigation purpose using either gravity or lifting mechanism. The structure generally consists of construction of foundation, apron, retaining wall and the checkdam. The width of the checkdam ranges between 1 - 2 m while the height varies between 1 - 2 m depending up on the gully depth. The length of the checkdam depends on the gully width. The spacing between adjacent checkdams is determined based on two factors, namely, the gradient of the river bed and the availability of potential land that can be irrigated. It is also provided with a number of sluice gates which will be removed during the main rainy season to minimize siltation.

Purpose of the Technology: In addition to storing water for irrigation, check dam ponds decrease slope length, slope angle, runoff velocity and minimize soil erosion.

Establishment / maintenance activities and inputs: Establishment of a check dam pond starts with collection and transportation of stone and sand. The construction is started by setting out the dimensions from the design on the selected site and excavating the foundation for the different parts, namely, key trench, apron and retaining wall. The check dam is then constructed using gabions filled with stones and tightly tied together with wire. Finally the superstructure is plastered using mortar to prevent the passage of water through the body. Gates of about 1 m wide are finally constructed at about 1 m interval and fitted with sluice gates. Maintenance usually involves fixing damaged gates and reinforcing gabions.

Natural / human environment: Check dam pond is implemented in gentle (2 - 5%) and moderate (5 - 8%) slopes and in medium and light soil types of at least 1 m depth. It increases water availability for irrigation and livestock consumption purposes. It also reduces runoff velocity thereby decreasing soil erosion and enhancing gully rehabilitation.

It requires skilled labour and high construction cost. As a result, it is constructed through external support. However, the number of communities seeking for external support and willing to contribute their share is at the rise. The technology minimizes greatly the risk of crop failure and improves the livelihood of the land users.

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:

• hace menos de 10 años (recientemente)

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• mediante proyectos/ intervenciones externas

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

Comentarios:

Major land use problems (compiler’s opinion): Deforestation and overgrazing, high erosion risk, gully formation and land loss, decline in productivity.

Major land use problems (land users’ perception): Population pressure, deforestation, flood, soil erosion, reduced productivity.

3.3 Información adicional sobre el uso de tierras

Provisión de agua para la tierra donde se aplica la Tecnología:

• mixta de secano – irrigada

Número de temporadas de cultivo por año:

• 2

Especifique:

Longest growing period in days: 150Longest growing period from month to month: June - NovemberSecond longest growing period in days: 105Second longest growing period from month to month: January - April

3.4 Grupo MST al que pertenece la Tecnología

• cosecha de agua
• Manejo de irrigación: (incl. provisión de agua, invernaderos)
• manejo de agua superficial (manantial, río, lagos, mar):

3.5 Difusión de la Tecnología

Especifique la difusión de la Tecnología:

• distribuida parejamente sobre un área

Si la tecnología se halla difundida homogéneamente en un área, indique el área aproximada que cubre:

• 1-10 km2

3.6 Medidas MST que componen la Tecnología

Comentarios:

Main measures: structural measures

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

Main type of degradation addressed: Wg: gully erosion / gullying

Secondary types of degradation addressed: Wt: loss of topsoil / surface erosion, Wm: mass movements / landslides, Wo: offsite degradation effects

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires), Heavy / extreme rainfall (intensity/amounts), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Steep topography that increases amount and velocity of flood), population pressure

Secondary causes of degradation: crop management (annual, perennial, tree/shrub), over-exploitation of vegetation for domestic use, overgrazing, floods, land tenure, poverty / wealth, education, access to knowledge and support services

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

Comentarios:

Main goals: mitigation / reduction of land degradation

Secondary goals: rehabilitation / reclamation of denuded land

4.1 Dibujo técnico de la Tecnología

4.2 Especificaciones técnicas/ explicaciones del dibujo técnico

Check dam ponds are raised walls constructed across a stream/gully using stone, concrete and/or gabion for dual purpose, namely, to pond/store the stream flow behind it for irrigation purpose while at the same time reducing the runoff velocity and enhancing gully rehabilitation.

Location: Tigray. Kilte Awlaelo

Date: 10/10/2014

Technical knowledge required for field staff / advisors: high

Technical knowledge required for land users: high

Technical knowledge required for Engineer/designer: high

Main technical functions: control of dispersed runoff: impede / retard, reduction of slope length

Secondary technical functions: reduction of slope angle, increase of infiltration, increase of groundwater level / recharge of groundwater, sediment retention / trapping, sediment harvesting

Wall/ barrier
Vertical interval between structures (m): n/a
Spacing between structures (m): n/a
Height of bunds/banks/others (m): 1 - 2
Width of bunds/banks/others (m): 1 - 2

Construction material (stone): Stones are usually shaped in order to piece together very well.

Construction material (concrete): The chekdam is usually plastered by concrete on the upstream side to prevent the passage of water th

Construction material (other): Gabion, Sheet metal and Angle iron.

Slope (which determines the spacing indicated above): 2 - 8%

Lateral gradient along the structure: 0%

4.3 Información general sobre el cálculo de insumos y costos

otra / moneda nacional (especifique):

Birr

Indique la tasa de cambio de USD a la moneda local (si fuese relevante): 1 USD =:

18,0

4.4 Actividades de establecimiento

	Actividad	Tipo de medida	Momento
1.	Site clearance and excavation of foundation	Estructurales	Dry season
2.	Stone collection and transportation	Estructurales	Dry season
3.	Sand collection and transportation	Estructurales	Dry season
4.	Gabion masonry work	Estructurales	Dry season
5.	Plastering	Estructurales	Dry season

4.5 Costos e insumos necesarios para el establecimiento

	Especifique insumo	Unidad	Cantidad	Costos por unidad	Costos totales por insumo	% de los costos cubiertos por los usuarios de las tierras
Mano de obra	Labour	ha	1,0	4678,0	4678,0	25,0
Material de construcción	Cement	ha	1,0	953,0	953,0
Material de construcción	Gabion	ha	1,0	6268,0	6268,0
Material de construcción	Sheet metal	ha	1,0	44,0	44,0
Material de construcción	Angle iron	ha	1,0	56,0	56,0
Costos totales para establecer la Tecnología					11999,0

Comentarios:

Duration of establishment phase: 6 month(s)

4.6 Actividades de establecimiento/ recurrentes

	Actividad	Tipo de medida	Momento/ frequencia
1.	Fixing damaged gates and reinforcing gabions	Estructurales	Dry season

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

Comentarios:

Machinery/ tools: Digging hoe, shovel, hammer, crow bar

Since the check dam ponds generally vary in depth, width and most importantly in length depending up on the gully profile, calculation of cost per meter length will not be a reliable presentation. As a result, one typical check dam pond was selected and the total volume of the structure and the corresponding total cost of construction calculated. Then, the cost per cubic meter of the check dam was determined by dividing the total construction cost to the total volume of the structure.

The calculation includes the cost for the purchase of industrial materials (cement, gabion, sheet metal and angle iron) and cost of labour used for the construction including site clearance and excavation of foundation, stone and sand collection and transportation, gabion masonry work and plastering.

The price of the industrial materials and the labour wage used in the cost calculation apply to 2012. The daily labour wage for plastering is 180 Birr while it is 50 Birr for all other works.

4.8 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

Labour, availability of construction material, depth and width of gully.

5.1 Clima

5.2 Topografía

5.3 Suelos

Si se halla disponible, adjunte una descripción completa de los suelos o especifique la información disponible, por ej., tipo de suelo, pH/ acidez de suelo, capacidad de intercambio catiónico, nitrógeno, salinidad, etc. :

Soil fertility is low (medium soils, ranked 1) and very low (light soils, ranked 2)
Soil drainage/infiltration is medium (ranked 1) and good (ranked 2)
Soil water storage capacity is medium (ranked 1) and low (ranked 2)

5.4 Disponibilidad y calidad de agua

Comentarios y especificaciones adicionales sobre calidad y cantidad de agua:

Availability of surface water is good (September - January). Also medium (February-June)

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:

Land users applying the Technology are mainly common / average land users
Population density: 100-200 persons/km2
Annual population growth: 2% - 3%
10% of the land users are rich and own 10% of the land.
60% of the land users are average wealthy and own 55% of the land (35 Birr/day/person).
30% of the land users are poor and own 35% of the land.

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)
• individual

Derechos de uso de agua:

• comunitarios (organizado)

5.9 Acceso a servicios e infraestructura

6.1 Impactos in situ demostrados por la Tecnología

Impactos socioeconómicos

Producción

Disponibilidad y calidad de agua

Ingreso y costos

Impactos socioculturales

Impactos ecológicos

Ciclo de agua/ escurrimiento de sedimento

Suelo

Biodiversidad: vegetación, animales

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)

Extremos (desastres) relacionados al clima

Desastres hidrológicos

	¿Cómo es que la tecnología soporta esto?
inundación general (río)	no muy 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:

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

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

There is no trend towards spontaneous adoption of the Technology

Comments on adoption trend: There is no trend for spontaneous adoption due to high costs. However, communities are increasingly seeking external support to implement this technology.

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del usuario de la tierra
Increased water availability for irrigation and livestock consumption How can they be sustained / enhanced? Watershed management
Reduced soil erosion How can they be sustained / enhanced? Construction of retaining walls
Increased employment opportunity and income from irrigation How can they be sustained / enhanced? Cultivation of high value crops

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave
Increased water availability for irrigation as well as livestock consumption How can they be sustained / enhanced? Integrated watershed management
Reduce slope length, angle and erosion risk and enhance gully rehabilitation How can they be sustained / enhanced? Regular maintenance of the structure

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?
High cost of construction	Selecting a site that has good availability of construction material and that can irrigate as large area as possible.
Require skilled labour	Training of land users
Labour intensive	Mass mobilization

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

Staff members of the Kilte Awlaelo Wereda Office of Agriculture and Rural Development and Office of Water Resources Development