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

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

Department of Resources and Environmental Science, Beijing Normal University (Department of Resources and Environmental Science, Beijing Normal University) - Chine

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

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

16/05/2002

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:

Auto-flowing slurry dams is filled with dense slurry by water flow from upland to maintain eroded soil particles and runoff.

2.2 Description détaillée de la Technologie

Description:

Falling water filled dams distribute widely in the middle reaches of the Yellow River, they are used to store water and wrap sediment which result from soil and water loss. On the Loess Plateau, in addition to the conditions of deep gully and steep slope, earth above the top of the dams can be used to build dams. First, soil is loosed with squirt guns, exploded or manually dug. Then, water is pumped up to the loose earth so as to rush the soil down along transporting ditch, turning the soil into dense mud to dam level surrounded by tamped banks. Under the press of gravity, the mud dehydrates, consolidates and becomes uniformly dense body of the dams. Compared with dams in other areas, the water power filled dams in the Yellow River basin are characterized by much denser mud, uniform particles and body texture, smaller transect of dams body, and wide applicability to soil materials such as sand soil, loess soil and weathering residue. The types of dams have widely applied to build moderate and small reservoirs and silt arresters in the middle reaches of the Yellow River, they play an important role in increase in agricultural production and reduction of sediment into the Yellow River.

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 plus de 50 ans (technologie traditionnelle)

2.7 Introduction de la Technologie

Spécifiez comment la Technologie a été introduite: :

• dans le cadre d'un système traditionnel (> 50 ans)

Commentaires (type de projet, etc.) :

The technology was developed by local people during the conservation practice in 1950s.

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

• améliorer la production

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

Commentaires:

Major land use problems (compiler’s opinion): 1. Slope land is used as cropland
2. Too little ground cover to protect soil from erosion
3. Over grazing in wind erosion area

Major land use problems (land users’ perception): 1. Little cropland for food supply
2. The land productivity is too low
3. The benefit of returning cropland to graze land or woodland is not definite now except the compensate from government

3.3 Informations complémentaires sur l'utilisation des terres

Nombre de période de croissance par an: :

• 1

Précisez:

Longest growing period in days: 165Longest growing period from month to month: May - Sep

3.4 Groupe de GDT auquel appartient la Technologie

• gestion de l'irrigation (incl. l'approvisionnement en eau, le drainage)

3.5 Diffusion de la Technologie

Spécifiez la diffusion de la Technologie:

• répartie uniformément sur une zone

Si la Technologie est uniformément répartie sur une zone, indiquez la superficie couverte approximative:

• > 10 000 km2

Commentaires:

Total area covered by the SLM Technology is 13062 m2.

Dams filled by water power are applied mainly in the middle reach of the Yellow River, including the provinces of Shanxi, Shaanxi, Inner Mongolia, Ningxia, Gansu, Qinghai, Henan, etc. The types of dams were used since 1950s, and most the dams being used were built in 1970s.

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Main measures: structural measures

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

Main type of degradation addressed: Wg: gully erosion / gullying, Ha: aridification

Secondary types of degradation addressed: Wt: loss of topsoil / surface erosion, Et: loss of topsoil, Cn: fertility decline and reduced organic matter content

Main causes of degradation: other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify, poverty / wealth (Lack of captial), education, access to knowledge and support services (Lack of knowledge)

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:

• non applicable

4.2 Spécification/ explications techniques du dessin technique

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

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

Secondary technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, reduction of slope angle, reduction of slope length, improvement of ground cover, increase of surface roughness, increase in organic matter, increase of infiltration, increase / maintain water stored in soil, water spreading, reduction in wind speed, increase in soil fertility, improvement of soil structure

Construction material (earth): Loess earth

Slope (which determines the spacing indicated above): 45%

If the original slope has changed as a result of the Technology, the slope today is: 30%

Lateral gradient along the structure: 60%

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

4.3 Informations générales sur le calcul des intrants et des coûts

Indiquez la monnaie utilisée pour le calcul des coûts:

• dollars US

4.4 Activités de mise en place/ d'établissement

	Activité	Type de mesures	Calendrier
1.	preparing earth	Structurel	n/a
2.	pumping water	Structurel	n/a
3.	preparing base of the dam and its perimetric banks	Structurel	n/a
4.	Flushing the prepared earth with water inside the banks of the dam	Structurel	0.1~1
5.	After dehydration and consolidation of the earth, repeat 3 and 4.	Structurel	n/a

4.5 Coûts et intrants nécessaires à la mise en place

Commentaires:

Duration of establishment phase: 540 month(s)

4.6 Activités d'entretien/ récurrentes

	Activité	Type de mesures	Calendrier/ fréquence
1.	Keeping the top of the dam level and free of crevice, water or rubbish	Structurel	timely
2.	Keeping the top of the dam level and free of crevice, water or rubbish	Structurel
3.	Keeping the slope of the dam compact and free of rill or weed.	Structurel	timely
4.	Keeping the slope of the dam compact and free of rill or weed.	Structurel
5.	Keeping the observation equipment work in order.	Structurel	timely
6.	Keeping the observation equipment work in order.	Structurel
7.	Preventing the base the dam from destroying by white ants and other animals.	Structurel	April to October/once a year

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

Commentaires:

The volume of structure.

4.8 Facteurs les plus importants affectant les coûts

Décrivez les facteurs les plus importants affectant les coûts :

Since the dam construction uses local materials, the most important factors affecting the cost are labor and equipment

5.1 Climat

5.2 Topographie

Indiquez si la Technologie est spécifiquement appliquée dans des:

• non pertinent

Commentaires et précisions supplémentaires sur la topographie:

Landform: Also plateau/plain

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: low
Soil drainage / infiltration: medium - good
Soil water storage capacity: high - very high

5.6 Caractéristiques des exploitants des terres appliquant la Technologie

Indiquez toute autre caractéristique pertinente des exploitants des terres:

Population density: 50-100 persons/km2

Annual population growth: 0.5% - 1%

Relative level of wealth: rich, average, poor
There are almost no people very rich in the area.
Rich people are as same as average people.
40% of the land users are average wealthy and own 20% of the land (Average people in the area where the SWC is applied should offer labor for the construction.).
Poor people can offer labor for the construction.
Very poor people are relatively rare and they are often in poor health.

Off-farm income specification: Most young male farmers often go to the city or town to earn money

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

Propriété foncière:

• état

Droits d’utilisation des terres:

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

6.1 Impacts sur site que la Technologie a montrés

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

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)?

6.5 Adoption de la Technologie

• 1-10%

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

80'000 households (3 percent of the area)

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?

• 10-50%

Commentaires:

5% of land user families have adopted the Technology with external material support

50000 land user families have adopted the Technology with external material support

Comments on acceptance with external material support: estimates

1% of land user families have adopted the Technology without any external material support

30000 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: estimates

There is a strong trend towards spontaneous adoption of the Technology

Comments on adoption trend: Although the local people adopt the SWC Technology willingly, it is usually invested, designed and constructed by the land owner, the local government.

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

Special Planning Of Soil And Water Conservation in Xinzhou Region , Shanxi Province. 1986-1990.

Disponible à partir d'où? Coût?

Library of the Resource and Environmental Department, Beijing Normal University.

Titre, auteur, année, ISBN:

How to design the dry masonry dam in the Hanjiachuan watershed. Tianyuzhu, Wangzuliang. Beijing. Water conservation in Beijing. 2000.

Disponible à partir d'où? Coût?

Library of the Resource and Environmental Department, Beijing Normal University.