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

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

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

20/01/2009

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:

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 Descripción detallada de la Tecnología

Descripción:

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 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 más de 50 años atrás (tradicional)

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• como parte de un sistema tradicional (> 50 años)

Comentarios (tipo de proyecto, 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 Propósito(s) principal(es) de la Tecnología MST

• reducir, prevenir, restaurar la degradación del suelo

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

Comentarios:

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

Si el uso de la tierra ha cambiado debido a la implementación de la Tecnología, indique el uso de la tierra antes de la implementación de la Tecnología.

Grazing land: Gi: Intensive grazing/ fodder production

3.3 Información adicional sobre el uso de tierras

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

• de secano

Número de temporadas de cultivo por año:

• 1

Especifique:

Longest growing period in days: 300Longest growing period from month to month: March to NovemberSecond longest growing period in days: 200Second longest growing period from month to month: April to October

3.4 Grupo MST al que pertenece la Tecnología

• medida de pendiente transversal

3.5 Difusión de la Tecnología

Comentarios:

Total area covered by the SLM Technology is 253.3 m2.

The total area with different measures is till to 2000. Yanhe River is a first class branch of Yellow River, China. The average channel slope is 3.26‰, and the area of whole basin is 7,687 km2. It is in the semi-arid North Temperate Zone with an average annual precipitation varying from 500 to 550 mm, and an average annual air temperature ranging from 8.5 to 11.4℃. It is in hilly gully area of the Loess Plateau covered by loess. The landform is seriously broken by cutting gullies induced by water erosion. The gully density (the length of channel in one km2) is amount to 2.1 to 4.6 km•km-2. The soil loss is severe all along.
The Ganguyi Hydrology Station (109°48′E, 36°42′N) located in the Ganguyi Town, Baota Country, Yan’an City, Shaanxi Province. The area up Ganguyi Hydrology Station is 5,891 km2, including of Jingbian County(256km2), Zhidan County(708km2), Ansai County(2,699km2) and Baota County(2,228km2). The average annual runoff is 0.22 billion m3, and the runoff modulus accounting for 4,776.36 m3•km-2•yr-1. The average annual sediment flow is 4.776

3.6 Medidas MST que componen la Tecnología

Comentarios:

Main measures: structural measures

Secondary measures: vegetative measures, management measures

Type of vegetative measures: aligned: -along boundary

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

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 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

Comentarios:

Main goals: mitigation / reduction of land degradation

4.1 Dibujo técnico de la Tecnología

4.2 Especificaciones técnicas/ explicaciones del dibujo técnico

The brief structure of terrace in the Yanhe River Basin.

Location: Zhifanggou Watershed. Ansai County, Shaanxi, China

Date: 2008-12-15

Technical knowledge required for field staff / advisors: low (The location selection and how to build a good terrace need special knowledge on soil engineering.)

Technical knowledge required for land users: moderate (It is easy to know the benefit for all the local farmers.)

Main technical functions: control of concentrated runoff: retain / trap, reduction of slope angle, increase of infiltration

Secondary technical functions: increase / maintain water stored in soil, improvement of water quality, buffering / filtering water, increase of biomass (quantity)

Aligned: -along boundary
Vegetative material: G : grass
Number of plants per (ha): 50000
Vertical interval between rows / strips / blocks (m): 2.5
Spacing between rows / strips / blocks (m): 0.5

Grass species: Natural grass to protect the bank of terrace.

Slope (which determines the spacing indicated above): 20.00%

If the original slope has changed as a result of the Technology, the slope today is (see figure below): 2.00%

Gradient along the rows / strips: 1.00%

Terrace: bench level
Vertical interval between structures (m): 2.5
Spacing between structures (m): 8
Height of bunds/banks/others (m): 2.5
Width of bunds/banks/others (m): 8
Length of bunds/banks/others (m): 50-100

Construction material (earth): The terrace in the Loess Plateau are used local soil/earth directly.

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

If the original slope has changed as a result of the Technology, the slope today is: 30-60%

Lateral gradient along the structure: 2%

Vegetation is used for stabilisation of structures.

Change of land use type: Wild grassland or range land before mostly. Some time the cropland on the slope.

Change of land use practices / intensity level: The labor is less intensive on the plain platform.

4.3 Información general sobre el cálculo de insumos y costos

Especifique la moneda usada para calcular costos:

• dólares americanos

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

0,83

4.4 Actividades de establecimiento

	Actividad	Tipo de medida	Momento
1.	Survey and design	Manejo	Before construction
2.	Move the topsoil to other place	Manejo	1st step of construction
3.	Built the platform and bank with soil digged	Manejo	2nd step of construction
4.	Backcover the topsoil on the surface of platform	Manejo	3rd step of construction
5.	Check and accept the terrace	Manejo	After the terrace finished

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	Survey and design	Person/day	45,0	8,8	396,0	100,0
Mano de obra	Building terraces (machine price included)	Person/day	75,0	19,0	1425,0	100,0
Costos totales para establecer la Tecnología					1821,0

Comentarios:

Duration of establishment phase: 0.5 month(s)

4.6 Actividades de establecimiento/ recurrentes

	Actividad	Tipo de medida	Momento/ frequencia
1.	Reinforce the bank	Estructurales	annually
2.	Fill the erosion hole of the landform	Estructurales	annually
3.	Build the edge in some terraces	Estructurales	annually
4.	Reinforce the bank	Manejo	annually
5.	Fill the erosion hole of the landform	Manejo	annually
6.	Build the edge in some terraces	Manejo	annually

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

	Especifique insumo	Unidad	Cantidad	Costos por unidad	Costos totales por insumo	% de los costos cubiertos por los usuarios de las tierras
Mano de obra	Keep Terraces in shape	Person/day	30,0	8,8	264,0	100,0
Indique los costos totales para mantenecer la Tecnología					264,0

Comentarios:

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.

4.8 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

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 Clima

5.2 Topografía

Indique si la Tecnología se aplica específicamente en:

• situaciones convexas

Comentarios y especificaciones adicionales sobre topografía :

Landforms also: mountain slopes and hill slopes

Slopes on average also very steep

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 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 Disponibilidad y calidad de agua

Comentarios y especificaciones adicionales sobre calidad y cantidad de agua:

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 Biodiversidad

Comentarios y especificaciones adicionales sobre biodiversidad:

It is very stable in this region.

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

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 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
• comunitaria/ aldea

Derechos de uso de tierra:

• individual

Derechos de uso de agua:

• acceso abierto (no organizado)

Comentarios:

Like other rural area in China.

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

Otros impactos ecológicos

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)

Cambio climático gradual

Cambio climático gradual

	Estación	tipo de cambios climáticos/ climas extremos	¿Cómo es que la tecnología soporta esto?
temperatura anual		incrementó	bien

Extremos (desastres) relacionados al clima

Desastres climatológicos:

	¿Cómo es que la tecnología soporta esto?
tormenta de lluvia local	no muy bien
tormenta de viento	bien

Desastres climatológicos

	¿Cómo es que la tecnología soporta esto?
sequía	no se sabe

Desastres hidrológicos

	¿Cómo es que la tecnología soporta esto?
inundación general (río)	bien

Otras consecuencias relacionadas al clima

Otras consecuencias relacionadas al clima

	¿Cómo es que la tecnología soporta esto?
periodo reducido de crecimiento	no se sabe

Comentarios:

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 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)?

Comentarios:

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

6.5 Adopción de la Tecnología

• 1-10%

Si tiene la información disponible, cuantifique (número de hogares y/o área cubierta):

100 households

De todos quienes adoptaron la Tecnología, ¿cuántos lo hicieron espontáneamente, es decir, sin recibir incentivos/ pagos materiales?

• 0-10%

Comentarios:

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 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del usuario de la tierra
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.

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave
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 Debilidades/ desventajas/ riesgos de la Tecnología y formas de sobreponerse a ellos

Debilidades/ desventajas/ riesgos desde la perspectiva del usuario de la tierra	¿Cómo sobreponerse a ellas?
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.

Debilidades/ desventajas/ riesgos desde la perspectiva del compilador o de otra persona de referencia clave	¿Cómo sobreponerse a ellas?
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.

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

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

¿Dónde se halla disponible? ¿Costo?

Library of ISWC, CAS

Título, autor, año, ISBN:

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

¿Dónde se halla disponible? ¿Costo?

Library of ISWC, CAS

Título, autor, año, ISBN:

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

¿Dónde se halla disponible? ¿Costo?

Library of ISWC, CAS

Título, autor, año, 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

¿Dónde se halla disponible? ¿Costo?

http://159.226.100.28/asp/Detail.asp

Título, autor, año, 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

¿Dónde se halla disponible? ¿Costo?

http://159.226.100.28/asp/Detail.asp