1.2 Detalhes do contato das pessoas capacitadas e instituições envolvidas na avaliação e documentação da tecnologia

Nome da(s) instituição(ões) que facilitou(ram) a documentação/ avaliação da Tecnologia (se relevante)

Haramaya University (HU) - Etiópia

1.3 Condições em relação ao uso da informação documentada através de WOCAT

Quando os dados foram compilados (no campo)?

02/05/2011

O/a compilador/a e a(s) pessoa(s) capacitada(s) aceitam as condições relativas ao uso de dados documentados através da WOCAT:

Sim

2.1 Descrição curta da tecnologia

Definição da tecnologia:

Stone wall check dams are built across a gully to collect alluvial soil and hinder further gully erosion.

2.2 Descrição detalhada da tecnologia

Descrição:

During the 1980s stone walls and terraces were introduced in Ethiopia in order to combat soil erosion. The technology of stone walls or terraces is used to stabilize hills or to refill gullies also in Bati, Ethiopia. Stone walls can form a very strong check dam to rehabilitate gullies even several meters deep.

Purpose of the Technology: Although stone walls can be used for different purposes, this case study is focusing on stone walls used to combat gully erosion. Farmers in the Bati region often use stone walls to rehabilitate gullies if the material is easily accessible, otherwise they may search for alternatives.

Establishment / maintenance activities and inputs: Following procedure is undertaken to build a stone wall check dam: After breaking the stones in the source-area they are transported to the target-area either by hand, by camels or by donkeys, depending on the distance. After digging a foundation for the wall of approximately 30 cm depth, the gap between two rows of big stones 1 m apart is filled up with smaller stones and gravel. These actions are repeated until the desired height and width of the wall are reached

Natural / human environment: The case study site, Bati, lays in an semiarid climatic zone on 1600 m a.s.l. Rainfalls are erratic and the rain sum per year is between 500-1000 mm. The landscape is very hilly with rather steep slopes. As almost in all Ethiopia, the area has a high population density and growth. The agricultural sector is very dominant and lead by a lot of small scale farming with a lot of livestock and small plots of cropland.

2.3 Fotos da tecnologia

2.5 País/região/locais onde a tecnologia foi aplicada e que estão cobertos nesta avaliação

2.6 Data da implementação

Caso o ano exato seja desconhecido, indique a data aproximada:

• 10-50 anos atrás

2.7 Introdução da tecnologia

Especifique como a tecnologia foi introduzida:

• através de projetos/intervenções externas

Comentários (tipos de projeto, etc.):

Soil and water conservation measures, including stone wall check dams, were mainly introduced to land users during the 1980s by the government. Sometimes the technology is not adequately performed though. In recent years the local Agricultural Office is teaching farmers how to correctly build soil and water conservation measures not only on a technology basis but to take care of an integrated watershed management.

3.1 Principal/principais finalidade(s) da tecnologia

• Reduz, previne, recupera a degradação do solo

3.2 Tipo(s) atualizado(s) de uso da terra onde a tecnologia foi aplicada

Comentários:

Major land use problems (compiler’s opinion): Deforestation, overgrazing, cultivation of erosion-sensitive areas or steep slopes.

Major land use problems (land users’ perception): Too much soil loss and land degradation, no vegetation cover and poor soil moisture.

Grazingland comments: Livestock is not fenced in. Children herd the animals and watch out that they do not browse through crop fields. In off-farming season crop residues are collected from the field and stored next to the field. Animals are allowed to eat the still remaining residues on the field. After that, the animals are fed by the collected crop residues.

Livestock is grazing on crop residues

Type of grazing system comments: Livestock is not fenced in. Children herd the animals and watch out that they do not browse through crop fields. In off-farming season crop residues are collected from the field and stored next to the field. Animals are allowed to eat the still remaining residues on the field. After that, the animals are fed by the collected crop residues.

3.3 Mais informações sobre o uso da terra

Abastecimento de água para a terra na qual a tecnologia é aplicada:

• Misto de precipitação natural-irrigado

Comentários:

Water supply: Also rainfed

Especifique:

Longest growing period in days: 90 Longest growing period from month to month: June until September

Densidade animal (se relevante):

> 100 LU /km2

3.4 Grupo de GST ao qual pertence a tecnologia

• Medidas de curva de nível

3.5 Difusão da tecnologia

Comentários:

Total area covered by the SLM Technology is 0.6 m2.

Size of the case study watershed.

3.6 Medidas de GST contendo a tecnologia

Comentários:

Main measures: structural measures

3.7 Principais tipos de degradação da terra abordados pela tecnologia

Comentários:

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

Secondary types of degradation addressed: Wt: loss of topsoil / surface erosion

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Deforestation for the past 30 years.), over-exploitation of vegetation for domestic use (Wood collection for cooking and construction.), overgrazing (50% of the watershed area are cultivated - big grazing pressure on remaining land), other human induced causes (specify) (Cultivation of very steep slopes.), change of seasonal rainfall (Erratic rainfall.), Heavy / extreme rainfall (intensity/amounts) (If there is rain, it is intensive.), population pressure (High population pressure.), poverty / wealth (Poor facilities.)

Secondary causes of degradation: soil management (Poor soil management practices and lack of awareness.), crop management (annual, perennial, tree/shrub) (Annual cropping.), droughts (The research area is considered rather dry.), land tenure (If the land is rented, it is poorly managed.), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (Poor access to fertilizer. Bad infrastructures.), education, access to knowledge and support services (Lack of awareness for soil degradation.), Low productivity of the land (As a consequence seeking for new/larger areas to increase production.)

3.8 Redução, prevenção ou recuperação da degradação do solo

Especifique o objetivo da tecnologia em relação a degradação da terra:

• Reduzir a degradação do solo
• Recuperar/reabilitar solo severamente degradado

Comentários:

Secondary goals: mitigation / reduction of land degradation

4.1 Desenho técnico da tecnologia

4.2 Especificações técnicas/ explicações do desenho técnico

Stone wall check dams as they can be found in the region of Bati. The approximately 1 m wide gap between two rows of larger stones is filled up with small stones or gravel. This is done for every new level of the wall until the wall reaches its final height. The first row of stones is placed in the top 30 cm of the ground and on each side the dam is entering the hill to some extent. After a wall has silted up, the height is increased by other rows of stones until desired dimension is reached. Walls up to 5 m can be found in the case study site.

Location: South-West of Bati. Bati Woreda, Amhara Region, Ethiopia

Date: 26.04.2011

Technical knowledge required for field staff / advisors: moderate (To teach the farmers how to perform an integrated watershed management.)

Technical knowledge required for land users: high (To build a robust check dam there is a lot of knowledge needed.)

Main technical functions: control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, reduction of slope angle, reduction of slope length, increase / maintain water stored in soil, sediment retention / trapping, sediment harvesting

Secondary technical functions: water harvesting / increase water supply, improvement of water quality, buffering / filtering water

Retention/infiltration ditch/pit, sediment/sand trap
Depth of ditches/pits/dams (m): 6
Width of ditches/pits/dams (m): 10
Length of ditches/pits/dams (m): 1

If the original slope has changed as a result of the Technology, the slope today is: 0%

4.3 Informação geral em relação ao cálculo de entradas e custos

Outro/moeda nacional (especifique):

Ethiopian Birr

Indique a taxa cambial do dólar norte americano para a moeda local (se relevante): 1 USD =:

16,82

4.4 Atividades de implantação

	Atividade	Tipo de medida	Periodicidade
1.	Preparation of the stones (500 person days needed).	Estrutural	During dry season.
2.	Transportation of the stones (depending on the distance).	Estrutural	During dry season.
3.	Digging a foundation of 30 cm depth (165 person days needed).	Estrutural	During dry season.
4.	Building of the stone wall (500 person days needed).	Estrutural	During dry season.

4.5 Custos e entradas necessárias para a implantação

	Especifique a entrada	Unidade	Quantidade	Custos por unidade	Custos totais por entrada	% dos custos arcados pelos usuários da terra
Mão-de-obra	Labour	ha	1,0	1165,0	1165,0	50,0
Equipamento	Tools	ha	1,0	5,0	5,0	100,0
Custos totais para a implantação da tecnologia					1170,0

4.6 Atividades recorrentes/manutenção

	Atividade	Tipo de medida	Periodicidade/frequência
1.	Prepare the stones (250 person days needed).	Estrutural	During dry season if needed.
2.	If dam is silted up, increasing the height by 0.5 m (250 person days needed)	Estrutural	Every year in dry season.

4.7 Custos e entradas necessárias pata a manutenção/atividades recorrentes (por ano)

	Especifique a entrada	Unidade	Quantidade	Custos por unidade	Custos totais por entrada	% dos custos arcados pelos usuários da terra
Mão-de-obra	Labour	ha	1,0	500,0	500,0	50,0
Equipamento	Tools	ha	1,0	5,0	5,0	100,0
Custos totais para a manutenção da tecnologia					505,0

Comentários:

Machinery/ tools: Shovel, digging hoe, iron rod.

Total costs of a hectare were calculated for a wall of 100 m length and 1 m of height every 20 m (500 m total wall) in the year 2011. Tool prices were estimated and labor costs were calculated with a daily wage of 1$.

4.8 Fatores mais importantes que afetam os custos

Descreva os fatores mais determinantes que afetam os custos:

Rough topology in the area, questionable availability of construction materials if they are not found nearby.

5.1 Clima

5.2 Topografia

Comentários e outras especificações sobre a topografia:

Altitudinal zone: 1501-2000 m a.s.l. (The study site is located at 1600m a.s.l.)
Landforms: Hill slopes (ranked 1) and valley floors (ranked 2)
Slopes on average: Hilly (ranked 1), rolling (ranked 2) and steep (ranked 3)

5.3 Solos

Caso disponível anexe a descrição completa do solo ou especifique as informações disponíveis, p. ex. tipo de solo, PH/acidez do solo, nitrogênio, capacidade de troca catiônica, salinidade, etc.

Soil depth on average: Very shallow (ranked 1) and shallow (ranked 2)
Soil textur: Coarse/light (ranked 1) and medium (ranked 2)
Soil fertility is low
Soil drainage/infiltration is poor
Soil water storage capacity is medium

5.4 Disponibilidade e qualidade de água

Comentários e outras especificações sobre a qualidade e a quantidade da água:

Ground water table: Unknown
Availability of surface water is poor/none (Only during rainy season)
Water quality (untreated): Poor drinking water (treatment required, mostly groundwater)

5.5 Biodiversidade

Comentários e outras especificações sobre biodiversidade:

Relative to other parts of Ethiopia.

5.6 Características dos usuários da terra que utilizam a tecnologia

Indique outras características relevantes dos usuários da terra:

Land users applying the Technology are mainly common / average land users
Population density: 100-200 persons/km2
Annual population growth: 6%
1% of the land users are rich (Adopt the most of SWC technologies).
19% of the land users are average wealthy.
89% of the land users are poor.
Off-farm income specification: Off-farm income has low importance.
Level of mechanization: Animal traction (Plowing by oxen, ranked 1) and manual labour (ranked 2)
Market orientation cropland: Subsistence
Market orientation grazing land: Goat/sheep are main meat source (in household or on market).

5.7 Média da área de terra própria ou arrendada por usuários da terra que utilizam a tecnologia

5.8 Propriedade de terra, direitos de uso da terra e de uso da água

Propriedade da terra:

• Indivíduo, intitulado

Direitos do uso da água:

• Acesso livre (não organizado)

5.9 Acesso a serviços e infraestrutura

6.1 Impactos no local mostrados pela tecnologia

Impactos socioeconômicos

Produção

Disponibilidade e qualidade de água

Renda e custos

Impactos socioculturais

Impactos ecológicos

Ciclo hídrico/escoamento

Solo

Biodiversidade: vegetação, animais

Clima e redução de riscos de desastre

6.2 Impactos externos mostrados pela tecnologia

6.3 Exposição e sensibilidade da tecnologia às mudanças climáticas graduais e extremos/desastres relacionados ao clima (conforme o ponto de vista dos usuários da terra)

Mudança climática gradual

Mudança climática gradual

	Estação do ano	Tipo de mudança climática/extremo	Como a tecnologia lida com isso?
Temperatura anual		aumento	bem

Extremos (desastres) relacionados ao clima

Desastres meteorológicos

	Como a tecnologia lida com isso?
Temporal local	bem
Tempestade de vento local	bem

Desastres climatológicos

	Como a tecnologia lida com isso?
Seca	bem

Desastres hidrológicos

	Como a tecnologia lida com isso?
Inundação geral (rio)	bem

Outras consequências relacionadas ao clima

Outras consequências relacionadas ao clima

	Como a tecnologia lida com isso?
Período de crescimento reduzido	bem

6.4 Análise do custo-benefício

Como os benefícios se comparam aos custos de implantação (do ponto de vista dos usuários da terra)?

Como os benefícios se comparam aos custos recorrentes/de manutenção(do ponto de vista dos usuários da terra)?

Comentários:

Big labour input for establishment. Also maintenance needs some work every year. But also high benefit by additional farming land gained due to the check dams.

6.5 Adoção da tecnologia

Comentários:

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

Comments on acceptance with external material support: In the past 6 years the local Agricultural Office has supported farmers to treat their watersheds with SWC technologies based on a food for work programme. Today farmers build the structures on their own but seek support.

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: Most of the farmers build SWC technologies (includin stone check dams in gullies) because of the food for work programme

6.7 Pontos fortes/vantagens/oportunidades da tecnologia

Pontos fortes/vantagens/oportunidades na visão do usuário da terra
The stone check dams are conserving soil and moisture. How can they be sustained / enhanced? Maintain the dams.
Due to alluvial soil there is additional farming land and therefore increased productivity. How can they be sustained / enhanced? Take care of the walls as well of the surrounding area and the whole watershed.

Pontos fortes/vantagens/oportunidades na visão do/a compilador/a ou de outra pessoa capacitada
Stone check dams are a quite durable structure. How can they be sustained / enhanced? Stability could be enhanced by additional technologies e.g. similar as gabbions or planting of trees/shrubs in front of the wall to reduce collapsing possibility.
The structure collects alluvial soil which can be plowed and used as new farming fields. How can they be sustained / enhanced? Structure maintenance is important. If the dam fails, the field is washed out as well.
The technology is widely used around the world (perhaps with local adaptations) and is therefore well documented. How can they be sustained / enhanced? Keep on with documentation and monitoring of limitations and potentials of stone check dams around the world.

6.8 Pontos fracos, desvantagens/riscos da tecnologia e formas de superá-los

Pontos fracos/desvantagens/riscos na visão do usuário da terra	Como eles podem ser superados?
The Land users could not tell any disadvantages of the technology.	Could be an indicator that there is enough spare time to build and maintain structures during off-farming season.

Pontos fracos/vantagens/riscos na visão do/a compilador/a ou de outra pessoa capacitada	Como eles podem ser superados?
Large labour input at establishment and during maintenance period.	Possibly by machinery but it is very expensive.
During time of establishment/maintenance there is no time for farming activites. These activities can therefore be seen as hidden costs.	Perhaps a "professional" team that takes care of check dams and is payed for it.

7.2 Referências às publicações disponíveis

Título, autor, ano, ISBN:

Bach S. (2012) Potentials and limitations of Jatropha curcas as a multipurpose crop for sustainable energy supply and soil and water conservation - a case study in Bati, Ethiopia, using the WOCAT approach. Unpublished master’s thesis, Centre for Development and Environment, University of Bern.