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

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

2.1 Courte description de la Technologie

Définition de la Technologie:

A Terrace is a structural SLM practice with a raised flat platform built on the slope to reduce soil loss and runoff on the slope, increase the rainfall infiltration and yield.

2.2 Description détaillée de la Technologie

Description:

A terrace is a leveled section of a hilly cultivated area, designed as a method of soil conservation to slow or prevent the rapid surface runoff and erosion of topsoil. Often such land is formed into multiple terraces, giving a stepped appearance.

Purpose of the Technology: To change the landform for better agricultural condition of operation of tillage and harvasting, reduction of soil erosion and water loss and finally for higher production.

Establishment / maintenance activities and inputs: The building of a terrace in the loess plateau takes long because loess is very soft and deep and the severe soil erosion and shortage of water in agriculture hinders the process, as well. Previously, terraces were constructed by hand. These terraces weres narrow and damaged by the great storms. Now, the machinery is used to build wide terrace with high bank size in the loess plateau. The establishment of terrace needs a lot of money but it is a long-term investment. The maintenance of terrace is considerable economic because the major efforts are the annually improvment of terrace bunds.

Natural / human environment: The soil erosion is very severe because of the cohesionless loess soil and very intensive rainfall storms in the summer and autumn that would destroy the land surface into broken hilly area. Terrace is a kind of measure to resolve it combining with crops. The human activities here is very intensive because they must plant on the slopes that would make the soil erosion greater.

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 terrace in this site has been formed since 1994 with machinery. The land is quite wide and large enough for agriculture in the hilly loess region,

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

• réduire, prévenir, restaurer les terres dégradées

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

Les divers types d'utilisation des terres au sein du même unité de terrain: :

Oui

Précisez l'utilisation mixte des terres (cultures/ pâturages/ arbres):

• Agroforesterie

Commentaires:

Main cash crops: Beans, sunflower, apple, Chinese date, alfalfa
Main food crops: Potato, millets, maize, buckwheat
other crops: vegetable

Major land use problems (compiler’s opinion): Soil and water losses are alarming in this region. The loose loess, steep slopes, and intensive storms in the summer and autumn, accelerates this process. Aditionally, the lack of rainfall negatively impacts agriculture and vegatation. Sediment deposition could increase the river bed and diminish capacity of reservoirs. On one hand side floods occur frequently because of fast and large runoff and on other hand side sedimentation in rivers reduce their water carring capacity.

Major land use problems (land users’ perception): The low yield of crops and the low income from land is more important for the local people. It is necessary to improve the agricultural conditions. The land, especially the tableland and gentle slope land could be convert into terrace.

Future (final) land use (after implementation of SLM Technology): Cropland: Ca: Annual cropping

Type of cropping system and major crops comments: The composation of agriculture is very simple here.

Livestock is grazing on crop residues

3.3 Est-ce que l’utilisation des terres a changé en raison de la mise en œuvre de la Technologie ?

Est-ce que l’utilisation des terres a changé en raison de la mise en œuvre de la Technologie ?

• Oui (Veuillez remplir les questions ci-après au regard de l’utilisation des terres avant la mise en œuvre de la Technologie)

3.4 Approvisionnement en eau

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

• pluvial

3.5 Groupe de GDT auquel appartient la Technologie

• mesures en travers de la pente

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Main measures: structural measures

Secondary measures: vegetative measures, management measures

Type of vegetative measures: aligned: -along boundary

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

Main type of degradation addressed: Wt: loss of topsoil / surface erosion

Secondary types of degradation addressed: Hs: change in quantity of surface water, Hw: reduction of the buffering capacity of wetland areas

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (The natural vegetation in this region is grass on theslope and trees on the gully and alluvial land. After the destroy of natural, the soil loss increases greatly.), Heavy / extreme rainfall (intensity/amounts) (About 70% of annual rainfall is in the summer and autumn. The storm is very intensive.), population pressure (The population density account for 71 capita per square km.)

Secondary causes of degradation: droughts (The rainfall varies greatly in different year and different seasons. The drought happened frenquently.)

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

Commentaires:

Main goals: mitigation / reduction of land degradation

4.1 Dessin technique de la Technologie

4.2 Informations générales sur le calcul des intrants et des coûts

Indiquez la monnaie utilisée pour le calcul des coûts:

• dollars américains

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

0,83

4.3 Activités de mise en place/ d'établissement

	Activité	Calendrier des activités (saisonnier)
1.	Survey and design	Before construction
2.	Move the topsoil to other place	1st step of construction
3.	Built the platform and bank with soil digged	2nd step of construction
4.	Backcover the topsoil on the surface of platform	3rd step of construction
5.	Check and accept the terrace	After the terrace finished

4.4 Coûts et intrants nécessaires à la mise en place

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% du coût supporté par les exploitants des terres
Main d'œuvre	Survey and design	Person/day	45,0	8,8	396,0	100,0
Main d'œuvre	Building terraces (machine price included)	Person/day	75,0	19,0	1425,0	100,0
Coût total de mise en place de la Technologie					1821,0
Coût total de mise en place de la Technologie en dollars américains (USD)					2193,98

Commentaires:

Duration of establishment phase: 0.5 month(s)

4.5 Activités d'entretien/ récurrentes

	Activité	Calendrier/ fréquence
1.	Reinforce the bank	annually
2.	Fill the erosion hole of the landform	annually
3.	Build the edge in some terraces	annually
4.	Reinforce the bank	annually
5.	Fill the erosion hole of the landform	annually
6.	Build the edge in some terraces	annually

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

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% du coût supporté par les exploitants des terres
Main d'œuvre	Keep Terraces in shape	Person/day	30,0	8,8	264,0	100,0
Coût total d'entretien de la Technologie					264,0
Coût total d'entretien de la Technologie en dollars américains (USD)					318,07

Commentaires:

Machinery/ tools: Crawl dozer and small traditional hand tool., crawler tractor, spade

In general condition, slope and soil, in the middle reaches of Yan River Basin. The prices of labour-day and Machine-hour are around 2005.

4.7 Facteurs les plus importants affectant les coûts

Décrivez les facteurs les plus importants affectant les coûts :

The terrace on the steep slope need more input for more soil and earth should be moved. It is the most important factor.The soil depth is not so important for the deep soil layer here.The cost of labour increases greatly in the last several years and the cost of construction of terrace increased.

5.1 Climat

5.2 Topographie

Indiquez si la Technologie est spécifiquement appliquée dans des:

• situations convexes

Commentaires et précisions supplémentaires sur la topographie:

Landforms also: mountain slopes and hill slopes

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 texture: There are more than 50% soil particle are fine sand with size between 0.05 and 0.1 mm.

Soil fertility very low: Lack of N, P and SOM.

Topsoil organic matter: The average Top-SOM of cropland is about 0.05%

Soil drainage / infiltration good: The inflitration of Loess is very fast, but it is prone to sealing when flashing.

Soil water storage capacity low: It is easy to evaporation and drainage.

5.4 Disponibilité et qualité de l'eau

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

Availability of surface water medium: It is very stable in this region.

Availability of surface water also poor/none: Nearly all the branches of Yanhe are seasonal river.

Ground water table: It depends on the landform. In valley and alluvial land, it is shallow.

Water quality: Good quality for there are few pollution sources.

5.5 Biodiversité

Commentaires et précisions supplémentaires sur la biodiversité:

It is very stable in this region.

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

Difference in the involvement of women and men: No clear difference.

Population density: 50-100 persons/km2

Annual population growth: < 0.5%

80% of the land users are average wealthy (The terrace are build together in some villages for all the people funded by national subsidy.).

Off-farm income specification: The yield of terrace is much high and stable.

Level of mechanization manual work: The harvesting and other management are by hand, even the tillage on the nerrow terrace

Level of mechanization animal traction: Tillage with animal power mostly in the wider terrace.

Market orientation mixed subsistence/ commercial: Some production for themselves, but most of production is exchanged on the market.

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:

• état
• communauté/ village

Droits d’utilisation des terres:

• individuel

Droits d’utilisation de l’eau:

• accès libre (non organisé)

Commentaires:

Like other rural area in China.

5.9 Accès aux services et aux infrastructures

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Production

Disponibilité et qualité de l'eau

Revenus et coûts

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

Biodiversité: végétale, animale

Autres impacts écologiques

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	Augmentation ou diminution	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	pas connu

Catastrophes hydrologiques

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

Commentaires:

Loess is very prone to erosion and extreme storms would destory the bank of terrace. In the study site sesonal rainfall increased and the loess terrace could retain more soil water and reduce the runoff.

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:

The yield of terrace is stable and relative higher. The income from terrace is high and the maintain cost is low.

6.5 Adoption de la Technologie

• 1-10%

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

100 households

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:

90% of land user families have adopted the Technology with external material support

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

Comments on acceptance with external material support: Most land farmers have some terrace. I do not know the exact number of land user families who adopted the technology.

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

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

Comments on spontaneous adoption: the old narrow terraces, now a very small area left, are build voluntarily.

There is a strong trend towards spontaneous adoption of the Technology

Comments on adoption trend: Nearly all the people know the benefit of terrace. the benefits of terraces are very good for crops and orchards are high enough in this region.

6.7 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue de l'exploitant des terres
Increase yield and income. How can they be sustained / enhanced? If the terrace is maintained well, the water condition would be better than that on the slope land even in dry year with low precipitation.
Convenient to till and harvest How can they be sustained / enhanced? Tillage and harvesting is much easier on the plain flat land than on the slope. The maintainance of terrace is important.

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
Reduce soil erosion on the slope. How can they be sustained / enhanced? The loess soil is prone to erosion because of its loose character induced by fine sand content and low soil organic matter. The plain flat makes the dispersion and transportation of soil particls difficult.
Reduce runoff and increase the soil moisture How can they be sustained / enhanced? The runoff generation is smaller on the plain than on the slope. Slow movement of surface water lead to more soil infiltration.
Increase yield. How can they be sustained / enhanced? Water is the limit factor in the loess plateau. The yield would increase if there is enough water available.
Decrease flood risk. How can they be sustained / enhanced? It is a kind of off-site benefits because less runoff generation and gentle process of runoff decrease flooding. Reduction of sediment also diminish flood risk because the drainage capacity of channel and adjusting capacity of reservior increase when sedimentation decrease.

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

Faiblesses/ inconvénients/ risques du point de vue de l’exploitant des terres	Comment peuvent-ils être surmontés?
The output is also low in contrast with other industries.	No way to overcome it. The total and net income is too low because the area of terrace per capita is very small.
The income is relative compared with other industries.	No way to overcome it. The net income is low because the labour costs are increasing, and the total income because labour cost and very small area of terrace per capita.

Faiblesses/ inconvénients/ risques du point de vue du compilateur ou d'une autre personne ressource clé	Comment peuvent-ils être surmontés?
There is possible damage of terraces because the loess is very loosen and prone to collapse.	Keep upmaintaining the bank and land well.
Decrease runoff of lower stream.	No way to overcome it, but it also could decrease the risk of floods.

7.1 Méthodes/ sources d'information

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

Soil and water conservation records of Shaanxi Province. 2000. Shaanxi People's Press, Xi'an City, China

Disponible à partir d'où? Coût?

Library of ISWC, CAS

Titre, auteur, année, ISBN:

The soil and agriculture of the Loess Plateau. 1989. Zhu Xianmo, Agriculture Press, Beijing City, China

Disponible à partir d'où? Coût?

Library of ISWC, CAS

Titre, auteur, année, ISBN:

Statistical tearbook of Yan'an. 2003. Compiled by Editorial Board of Statistical tearbook of Yan'an

Disponible à partir d'où? Coût?

Library of ISWC, CAS

Titre, auteur, année, ISBN:

Impact of human activities on runoff and sediment change of Yanhe River based on the periods divided by sediment concentration. 2008. WANG Fei , MU Xing-min ,JIAO Ju-ying, LI Rui. Journal of Sediment Research

Disponible à partir d'où? Coût?

http://159.226.100.28/asp/Detail.asp

Titre, auteur, année, ISBN:

Changes of soil erosion intensity due to conversion of farmland to forest and grassland in Yanhe River. 2007. BasinWang Bangwen, yang Qinke, Liu Zhihong, Meng Qingxiang, Science of Soil and Water Conservation

Disponible à partir d'où? Coût?

http://159.226.100.28/asp/Detail.asp