1.2 Coordonnées des personnes-ressources et des institutions impliquées dans l'évaluation et la documentation de la Technologie

Nom du projet qui a facilité la documentation/ l'évaluation de la Technologie (si pertinent)

Nom du ou des institutions qui ont facilité la documentation/ l'évaluation de la Technologie (si pertinent)

Nom du ou des institutions qui ont facilité la documentation/ l'évaluation de la Technologie (si pertinent)

1.3 Conditions relatives à l'utilisation par WOCAT des données documentées

Le compilateur et la(les) personne(s) ressource(s) acceptent les conditions relatives à l'utilisation par WOCAT des données documentées:

Oui

1.5 Référence au(x) Questionnaires sur les Approches de GDT (documentées au moyen de WOCAT)

Participatory approach [Rwanda]

This approach is a contribution of different stakeholders and land users in the identification and resolution of a particular crop land problems, which implicate at the end different stage of intervention by all stakeholders to resolve the problem.

• Compilateur : Desire Kagabo
• 9 fév. 2013 00:00

2.1 Courte description de la Technologie

Définition de la Technologie:

Lining geomembrane plastic for water harvesting and storage is a rainwater harvesting technique used by land users to collect rain water or runoff from a concave watershed to a common well-structured plastic-lined pond for agricultural, domestic and other use.

2.2 Description détaillée de la Technologie

Description:

Rainwater harvesting initiatives were introduced in Rwanda in 2007, through a government-supported project on a pilot basis in three districts (Ruhango, Bugesera and Kirehe). By 2011, the technology had expanded at exponential rates such that the demand has exceeded the supply. Now the supply policy has shifted from government to private still there is a shortage of plastic lining. The typical design of each pond is trapezoidal in shape, measuring 10.5 by 9 meters top-width, 6.5 by 5 meters bottom width and 2 meters depth and a total storage volume about 120 m3. The plastic lining is factory–manufactured with standard shape and size to fit these dimensions. The ponds are made with this standard design to enable bulk purchase and supply of geo-membranes, to make use of economies of scale. The cost of the geo-membranes was subsidized by up to 100% by the government until 2010 but now only 20% are provided by the government. When this project was initiated, activities related to soil excavation was done by the government. However, with time the government pulled out and farmers are now covering the total cost of excavation and the government intervenes only for the technical compliance. The government provides technicians to train farmers on the safety and management of ponds. The volume of water harvested and stored in the ponds is on average 90 m3. However, water retention within the ponds over time differs with from farm to farm as affected by usage, evaporation and seepage losses. Treadle pumps are sometimes used to lift water by some of the farmers. Among most households, the water from the pond is used for domestic, livestock and supplemental irrigation, especially of horticultural crops. About 20% of the water is used for seedling and fruit production, 75% for livestock watering and 5% for domestic use. When the excavation of the pond is complete, the beds as well as sides of the pond have to be leveled and prepared for laying the lining plastic. Any rocks, large stones or other projections, which might damage the lining plastic, should be removed from the beds and sides of the excavated ponds.

Purpose of the Technology: Lining geomembrane plastic for water storage is designed to reduce seepage losses in ponds. This water is used by smallholder farmers to cope with the beginning of dry season and enhance crops to reach the maturity stage safely.

Establishment / maintenance activities and inputs: A periodical inspection is required for better life of the pond, thus timely maintenance hold the key of success for longer time. The maintenance includes inspection, repairing damages. Regular investigations are required on the pond sides, bottom, the inlet and the emergency outlet. In addition, the pond should be protected from intrusion of animals by constructing a fence around the pond. It is also important to remove aquatic vegetation, silt and sediment periodically that accumulate on the bottom of the pond.

2.3 Photos de la Technologie

2.5 Pays/ région/ lieux où la Technologie a été appliquée et qui sont couverts par cette évaluation

Pays:

Rwanda

Région/ Etat/ Province:

Rwanda

Autres spécifications du lieu:

Kayonza District (East provice)

Spécifiez la diffusion de la Technologie:

• répartie uniformément sur une zone

S'il n'existe pas d'informations exactes sur la superficie, indiquez les limites approximatives de la zone couverte:

• < 0,1 km2 (10 ha)

Commentaires:

The area was estimated.

Map

×

2.6 Date de mise en œuvre de la Technologie

Si l'année précise est inconnue, indiquez la date approximative: :

• il y a moins de 10 ans (récemment)

2.7 Introduction de la Technologie

• Government

Commentaires (type de projet, etc.) :

the technology was initiated in 2008

3.1 Principal(aux) objectif(s) de la Technologie

• access to water

3.2 Type(s) actuel(s) d'utilisation des terres, là où la Technologie est appliquée

Terres cultivées

• Cultures annuelles

Cultures annuelles - Précisez les cultures:

• céréales - maïs
• légumineuses et légumes secs - fèves
• légumes - autres

Précisez:

Longest growing period in days: 150; Longest growing period from month to month: September – February; Second longest growing period in days: 120; Second longest growing period from month to month: March – July

Commentaires:

major cash crop: Vegetables
major food crop: Beans
other: Maize

Major land use problems (compiler’s opinion): There were poor yields of crops caused by elongation of dry season and increase of runoff soil erosion (intensive rain during rainy seasons) at the previous season.

Major land use problems (land users’ perception): Low crop production, soil erosion

Livestock is grazing on crop residues

3.4 Approvisionnement en eau

Approvisionnement en eau des terres sur lesquelles est appliquée la Technologie:

• mixte: pluvial-irrigué

3.5 Groupe de GDT auquel appartient la Technologie

• récupération/ collecte de l'eau

3.6 Mesures de GDT constituant la Technologie

structures physiques

• S5: Barrages/retenues, micro-bassins, étangs

3.7 Principaux types de dégradation des terres traités par la Technologie

érosion hydrique des sols

• Wg: ravinement/ érosion en ravines
• Wo: effets hors-site de la dégradation

dégradation hydrique

• Ha: aridification

Commentaires:

Secondary types of degradation addressed: Ha: aridification

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Steep slopes in many cases over 60%), population pressure (Rwanda’s natural resource is subject to a high density of population with an average of 400 people per ha)

Secondary causes of degradation: overgrazing, urbanisation and infrastructure development, poverty / wealth (Farmers have low income and have less access to off farm income or remittances), education, access to knowledge and support services (High rate of irriteracy)

3.8 Prévention, réduction de la dégradation ou réhabilitation des terres dégradées

Spécifiez l'objectif de la Technologie au regard de la dégradation des terres:

• réduire la dégradation des terres

4.1 Dessin technique de la Technologie

Spécifications techniques (associées au dessin technique):

Surface runoff water storage pond have got a reservoir of 10.5m x 9.5m at top and 6.5m x 5m at bottom and a depth of 2m with side slope of 1:1.5. The capacity of one pond is estimated about 120m3.

Location: Kabarondo. Kayonza/West/Rwanda

Date: 2013

Technical knowledge required for field staff / advisors: high (The technology need skilled engineers)

Technical knowledge required for land users: moderate (It need moderately skilled labor to construct the technology under supervision of engineers.)

Main technical functions: control of concentrated runoff: retain / trap, water harvesting / increase water supply

Secondary technical functions: water spreading

Dam/ pan/ pond
Vertical interval between structures (m): 2
Spacing between structures (m): 20
Depth of ditches/pits/dams (m): 2
Width of ditches/pits/dams (m): 9.5
Length of ditches/pits/dams (m): 10.5

Construction material (earth): the original land is digging

Construction material (stone): stones are used to concrete the pond inlet and outlet

Construction material (concrete): Cements, sand

Construction material (other): fencing wire and waterproof steering(plastic sheet)

Lateral gradient along the structure: 0%

Specification of dams/ pans/ ponds: Capacity 120m3

Catchment area: 6ham2

Beneficial area: valleym2

Slope of dam wall inside: 50%;
Slope of dam wall outside: 50%

Dimensions of spillways: 0.8m x0.6mm

For water harvesting: the ratio between the area where the harvested water is applied and the total area from which water is collected is: 1:0.25

Auteur:

Kagabo Desire and Ngenzi Guy, RAB, 5016 Kigali

4.2 Informations générales sur le calcul des intrants et des coûts

autre/ monnaie nationale (précisez):

Rwandan francs

Indiquez le taux de change des USD en devise locale, le cas échéant (p.ex. 1 USD = 79.9 réal brésilien): 1 USD = :

640,0

4.3 Activités de mise en place/ d'établissement

4.4 Coûts et intrants nécessaires à la mise en place

Commentaires:

Duration of establishment phase: 2 month(s)

4.5 Activités d'entretien/ récurrentes

4.6 Coûts et intrants nécessaires aux activités d'entretien/ récurrentes (par an)

Commentaires:

Machinery/ tools: hoes, meter, clinomrter, ect....

4.7 Facteurs les plus importants affectant les coûts

Décrivez les facteurs les plus importants affectant les coûts :

The most factors that affects the cost is the construction materials and labor.

5.1 Climat

5.2 Topographie

5.3 Sols

Si disponible, joignez une description complète du sol ou précisez les informations disponibles, par ex., type de sol, pH/ acidité du sol, capacité d'échange cationique, azote, salinité, etc.

Soil fertility is medium - high

Soil drainage / infiltration is medium

Soil water storage capacity is very high - high

5.4 Disponibilité et qualité de l'eau

5.5 Biodiversité

5.6 Caractéristiques des exploitants des terres appliquant la Technologie

Indiquez toute autre caractéristique pertinente des exploitants des terres:

Population density: 200-500 persons/km2

Annual population growth: 3% - 4%

55% of the land users are average wealthy and own 60% of the land.
45% of the land users are poor and own 40% of the land.

Market orientation of production system: (Begetables)

5.7 Superficie moyenne des terres utilisées par les exploitants des terres appliquant la Technologie

5.8 Propriété foncière, droits d’utilisation des terres et de l'eau

Propriété foncière:

• individu, avec titre de propriété

Droits d’utilisation des terres:

• individuel

Droits d’utilisation de l’eau:

• accès libre (non organisé)
• communautaire (organisé)

5.9 Accès aux services et aux infrastructures

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Production

Revenus et coûts

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

Biodiversité: végétale, animale

6.2 Impacts hors site que la Technologie a montrés

6.3 Exposition et sensibilité de la Technologie aux changements progressifs et aux évènements extrêmes/catastrophes liés au climat (telles que perçues par les exploitants des terres)

Changements climatiques progressifs

Changements climatiques progressifs

Extrêmes climatiques (catastrophes)

Catastrophes météorologiques

Catastrophes climatiques

Catastrophes hydrologiques

6.4 Analyse coûts-bénéfices

Quels sont les bénéfices comparativement aux coûts de mise en place (du point de vue des exploitants des terres)?

Quels sont les bénéfices comparativement aux coûts d'entretien récurrents (du point de vue des exploitants des terres)?

Commentaires:

It require light labor during the maintenance activities

6.5 Adoption de la Technologie

• > 50%

Si disponible, quantifiez (nombre de ménages et/ou superficie couverte):

260 household covering 90 percent of stated area

De tous ceux qui ont adopté la Technologie, combien d'entre eux l'ont fait spontanément, à savoir sans recevoir aucune incitation matérielle, ou aucune rémunération? :

• 0-10%

Commentaires:

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

10 land user families have adopted the Technology without any external material support

There is a little trend towards spontaneous adoption of the Technology

6.7 Points forts/ avantages/ possibilités de la Technologie

6.8 Faiblesses/ inconvénients/ risques de la Technologie et moyens de les surmonter

7.1 Méthodes/ sources d'information

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

Kagera TAMP project website

Disponible à partir d'où? Coût?

http://www.fao.org/nr/kagera/en/