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)

People and Resource Dynamics Project, Nepal (PARDYP)

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

ICIMOD International Centre for Integrated Mountain Development (ICIMOD) - Népal

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

Quand les données ont-elles été compilées (sur le terrain)?

01/11/2004

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) questionnaire(s) sur les Approches de GDT

2.1 Courte description de la Technologie

Définition de la Technologie:

Small dam structures constructed across erosion gullies

2.2 Description détaillée de la Technologie

Description:

Check dams are small low structures built across a gully or a channel to prevent them from deepening further. These small dams reduce the speed of water flow and minimise the erosive power of runoff. They also promote the deposition of eroded materials to further stabilise the gullies.
Two gullies adjacent to a degraded area of communal grazing land were controlled by constructing check dams and with vegetative measures including planting bamboo. The main purpose was to control the further development of the gullies, which were affecting the adjacent grazing land and blocking a downstream irrigation channel. The site is community land used by the 40 households (240 people) of Dhotra village in the intensively used Jhikhu Khola watershed. Irrigated cropland lies downstream from the site, whilst the site itself is bordered by grazing land, degraded sal-dominated forest, and rainfed forward-sloping terraces.
The check dams were made of old cement bags filed with soil and were 1m high with 0.5m deep foundations. The check dams were spaced so that a line joining the top of two adjacent dams had about a 3% slope gradient. Twenty-four check dams were built in the two gullies using a total of 2400 filled cement bags. Forty clumps of bamboo were planted between the dams for stabilisation.
All that is needed to maintain this technology is to inspect the condition of the check dams occasionally, especially before and after the monsoon. Displaced bags should be replaced and the water courses cleared of branches and big stones. Further planting should be carried out if needed.
The case study area has a distinct dry season from November to May and a wet monsoon period from June to October. Annual rainfall is around 1200 mm. The site has red soils that are highly weathered and, if not properly managed, are very susceptible to erosion.

2.3 Photos de la Technologie

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

2.6 Date de mise en œuvre de la Technologie

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

• il y a entre 10-50 ans

2.7 Introduction de la Technologie

Spécifiez comment la Technologie a été introduite: :

• par le biais de projets/ d'interventions extérieures

Commentaires (type de projet, etc.) :

The basic idea of this technology has its origin in traditional methods. However, villagers approached the People and Resource Dynamics Project (PARDYP) for advice. PARDYP assisted, based on experiences made before with rehabilitation/gully plugging experiments under similar conditions. Mainly developed according to theoretical and site specific knowledge.

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

• réduire, prévenir, restaurer les terres dégradées

• reduce land loss

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

Commentaires:

Major land use problems (compiler’s opinion): The major land use problem is the small per capita landholding size for cropping. These holdings are mostly rainfed, have a low soil fertility status and acidity problems, and are susceptible to erosion. Intense rainfall at the beginning of the rainy season causes considerable soil loss (rill and gully erosion).

Major land use problems (land users’ perception): Overgrazing leading to lack of vegetation and gully building.

Ranching: Yes

Future (final) land use (after implementation of SLM Technology): Forests / woodlands: Fp: Plantations, afforestations

Si l'utilisation des terres a changé en raison de la mise en œuvre de la Technologie, indiquez l'utilisation des terres avant la mise en œuvre de la Technologie:

Grazing land: Ge: Extensive grazing land

3.3 Informations complémentaires sur l'utilisation des terres

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

• pluvial

Nombre de période de croissance par an: :

• 3

Précisez:

Longest growing period in days: 150; Longest growing period from month to month: Jun - Oct; Second longest growing period in days: 120; Second longest growing period from month to month: Nov - Feb

3.4 Groupe de GDT auquel appartient la Technologie

• Amélioration de la couverture végétale/ du sol
• mesures en travers de la pente

3.5 Diffusion de la Technologie

Commentaires:

Total area covered by the SLM Technology is 0.006 km2.

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Main measures: vegetative measures, structural measures

Type of vegetative measures: scattered / dispersed

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

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

Secondary types of degradation addressed: Wo: offsite degradation effects

Main causes of degradation: overgrazing (insufficient forage supply from the private land.), education, access to knowledge and support services (identification of appropriate SWC technologies and appropriate collaborators)

Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (for daily household needs ( litter , firewood, timber), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (excessive rainfall during pre-monsoon and monsoon), poverty / wealth (to buy planting materials and for logistics), labour availability (for community level social work)

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

4.2 Spécification/ explications techniques du dessin technique

Schematic drawing of two gullies
with 24 check dams and bamboo
planted below the check dams for
stabilisation

Location: Dhotra. Khabre

Date: 22.6.06

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

Main technical functions: control of dispersed runoff: impede / retard, sediment retention / trapping, sediment harvesting

Secondary technical functions: reduction of slope angle, increase of infiltration

Scattered / dispersed
Vegetative material: T : trees / shrubs
Number of plants per (ha): 40
Vertical interval between rows / strips / blocks (m): 4 m

Trees/ shrubs species: Bamboo

Slope (which determines the spacing indicated above): 30.00%

If the original slope has changed as a result of the Technology, the slope today is (see figure below): 25.00%

Dam/ pan/ pond
Vertical interval between structures (m): 4 m

Construction material (earth): soil resulting from digging activities from the adjacent grassland was used to fill cement bags for

Slope (which determines the spacing indicated above): 30%

If the original slope has changed as a result of the Technology, the slope today is: 25%

Vegetation is used for stabilisation of structures.

4.3 Informations générales sur le calcul des intrants et des coûts

autre/ monnaie nationale (précisez):

Nepali Rupee

Indiquer le taux de change du dollars en monnaie locale (si pertinent): 1 USD= :

73,0

4.4 Activités de mise en place/ d'établissement

	Activité	Type de mesures	Calendrier
1.	Plantating of bamboo plants (clumps) below the check dams	Végétale	before onset of monsoon (June)
2.	Placing filled cement bags across gullies to form checkdams	Structurel	before onset of monsoon (June)
3.	Filling cement bag with soil	Structurel	before onset of monsoon (June)
4.	Digging trenches for dam foundations	Structurel	before onset of monsoon (June)

4.5 Coûts et intrants nécessaires à la mise en place

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% des coût supporté par les exploitants des terres
Main d'œuvre	Building dams and planting bamboo	Persons/day	18,0	2,0	36,0	100,0
Matériaux de construction	Cement bags	ha	1,0	73,0	73,0
Autre	Lunch, tea for farmers	ha	1,0	16,0	16,0
Autre	Transportation	ha	1,0	14,0	14,0
Coût total de mise en place de la Technologie					139,0

Commentaires:

Duration of establishment phase: 12 month(s)

4.6 Activités d'entretien/ récurrentes

	Activité	Type de mesures	Calendrier/ fréquence
1.	Maintaining gullies: repair or replace damaged check dams, plant	Végétale	before onset of monsoon (June)
2.	Ensuring good drainage for bamboo	Végétale	before onset of monsoon (June)
3.	Maintaining gullies: repair or replace damaged check dams,plant more grassesor trees if needed	Structurel	before onset of monsoon (June)/once a year

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

Commentaires:

Machinery/ tools: Spade, shovel, Spade, shovel

All costs and amounts were roughly estimated by the technicians and authors in 2004.

5.1 Climat

5.2 Topographie

Commentaires et précisions supplémentaires sur la topographie:

Altitudinal zone: 900 m a.s.l.

Slopes on average: Also very steep

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 depth on average: Very shallow at some places parent rockmaterial is exposed but variable.

Soil texture: Red soils with high clay content

Soil fertility was very low before implementation of rehabilitation activities.

Topsoil organic matter before implementation of rehabilitation activities.

Soil drainage / infiltration was poor before implementation of rehabilitation activities.

Soil water storage capacity was very low before implementation of rehabilitation activities.

5.4 Disponibilité et qualité de l'eau

Commentaires et précisions supplémentaires sur la qualité et la quantité d'eau:

Water quality: More in rainy season (June- September), less in April/May

5.6 Caractéristiques des exploitants des terres appliquant la Technologie

Indiquez toute autre caractéristique pertinente des exploitants des terres:

Land users applying the Technology are mainly common / average land users

Population density: 200-500 persons/km2

Annual population growth: 2% - 3%

95% of the land users are average wealthy.
3% of the land users are poor.
2% of the land users are poor.

Off-farm income specification: In most farm households, off-farm income plays at least a minor and increasingly a major role. Occasional opportunities for off-farm income present themselves in the form of daily

5.7 Superficie moyenne des terres détenues ou louées par les exploitants appliquant la Technologie

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

Propriété foncière:

• état

Droits d’utilisation des terres:

• communautaire (organisé)

6.1 Impacts sur site que la Technologie a montrés

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

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

	Saison	Type de changements/ extrêmes climatiques	Comment la Technologie fait-elle face à cela?
températures annuelles		augmente	bien

Extrêmes climatiques (catastrophes)

Catastrophes météorologiques

	Comment la Technologie fait-elle face à cela?
pluie torrentielle locale	pas bien
tempête de vent locale	bien

Catastrophes climatiques

	Comment la Technologie fait-elle face à cela?
sécheresse	bien

Catastrophes hydrologiques

	Comment la Technologie fait-elle face à cela?
inondation générale (rivière)	pas bien

Autres conséquences liées au climat

Autres conséquences liées au climat

	Comment la Technologie fait-elle face à cela?
réduction de la période de croissance	bien

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:

Due to the high establishment costs, the short term benefit for the community only matches the costs. However, in the long-term the environmental benefit of rehabilitated land is high, and economic
benefit is positive.

6.5 Adoption de la Technologie

• plus de 50%

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

40 households in an area of 0.006 sq km

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

• 0-10%

Commentaires:

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

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

Comments on acceptance with external material support: survey results

Comments on spontaneous adoption: survey results

There is no trend towards spontaneous adoption of the Technology

Comments on adoption trend: No initiative could be seen in the area.

6.7 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue de l'exploitant des terres
Reduced soil erosion, rill erosion, and top soil loss How can they be sustained / enhanced? Regular maintenance of the structure and grasses is required
The technology is easy to maintain. How can they be sustained / enhanced? As above

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
It's a low cost technology , easy to apply, little knowledge needed. How can they be sustained / enhanced? Regular maintenance of the structure and grasses is required
The effect of the technology can be seen easily. How can they be sustained / enhanced? As above

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

Nakarmi, G. (2000) Soil Erosion Dynamics in the Middle Mountains of Nepal, a report submitted to PARDYP, ICIMOD, Kathmandu

Disponible à partir d'où? Coût?

ICIMOD

Titre, auteur, année, ISBN:

Schreier, H.; Brown, S.; Shah, P. B.; Shrestha, B.; Merz, J. (2002) Jhikhu Khola Watershed – Nepal, CD ROM. Vancouver: Institute for Resources and Environment, University of British Columbia.

Disponible à partir d'où? Coût?

ICIMOD

Titre, auteur, année, ISBN:

Shrestha, B. (2004) Progress Report PARDYP- Nepal. Paper presented at the PARDYP Access Mid Year Meeting, 19-22 July 2004, ICIMOD, Kathmandu

Disponible à partir d'où? Coût?

ICIMOD