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

Nome do projeto que facilitou a documentação/avaliação da Tecnologia (se relevante)

DESIRE (EU-DES!RE)

Nome do projeto que facilitou a documentação/avaliação da Tecnologia (se relevante)

Book project: Water Harvesting – Guidelines to Good Practice (Water Harvesting)

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

EEZA-CSIC (EEZA-CSIC) - Espanha

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

Consejería de Agricultura y Agua Murcia (CARM) - Espanha

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

Quando os dados foram compilados (no campo)?

12/06/2008

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:

Water harvesting from intermittent streams towards nearby fields and terraces during runoff events.

2.2 Descrição detalhada da tecnologia

Descrição:

Water shortage is one of the most limiting factors for sustainable agriculture in large parts of SE-Spain. Part of the solution of this problem may come from the restoration of traditional water harvesting structures. Many of these structures were widely used in SE-Spain already during Arab and Roman times, and are also widespread in N-Africa and the Middle East. However, nowadays in Spain many of them are abandoned and forgotten. Here, we describe the technology of a small earthen- or stone- built bund that diverts flood water from intermittent streams towards cultivated fields with almond orchards and/or cereals. The diverted water will temporarily flood the fields and provide the crops with water. Depending on the slope gradient and the amount of water to be harvested, the fields are organised as single terraces, or as a staircase of terraces. On fields with gradients above ~3%, terraces are necessary to reduce the gradient and to retain the floodwater as long as possible. Water is diverted from one terrace to the next through small spillways in the terrace. The spillways can best be fortified with stones to prevent bank gully formation. The extra input of surface water can double the almond yield. The use of these water harvesting structures is only possible under certain environmental and topographic conditions. The cultivated fields should be at a relatively short distance from an intermittent stream (<~50m), and the stream should have a sufficiently large upstream contributing area to provide significant amounts of runoff water during rainfall events. With these systems, water can be harvested up to 8 times per year, mostly in spring and autumn during high intensity rainfall events. A well designed Boquera system may provide up to 550 mm of additional water, in areas with an average annual rainfall of 300 m.

Purpose of the Technology: The goal of this technology is to increase crop yield. In addition, these structures help to reduce the intensity of floods and reduce the damage caused by them by reducing runoff volume in intermittent streams.

Establishment / maintenance activities and inputs: Water harvesting requires the identification of a suitable location for the construction of a diversion structure. This requires assessment of expected water inflow, which can usually be based on simple field observation during rainfall events and based on local knowledge of land users. It is, however, important to consider whether there are activities upstream that possibly affect the water quality (e.g. farm animals) and to assess the implications the water harvesting might have downstream. Permission is required from the water authorities to construct any type of water harvesting structure. Such structures are built by creating a small bund (<1m height) in the centre or to the side of a stream. Depending on the size, the bund can be built with a shovel or a tractor. The water harvesting structure will require control and some maintenance after each important runoff event. When strengthened with concrete, maintenance will be reduced to approximately once every 5 years.

Natural / human environment: Soils are mostly of shallow to medium depth (20-60 cm), and slopes are gentle to moderate (5-15%). The climate is semi-arid with a mean annual rainfall around 300 mm. Droughts, centred in summer commonly last for more than 4-5 months. Annual potential evapotranspiration rates larger than 1000 mm are common.

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:

• mais de 50 anos atrás (tradicional)

2.7 Introdução da tecnologia

Especifique como a tecnologia foi introduzida:

• Como parte do sistema tradicional (>50 anos)

Comentários (tipos de projeto, etc.):

Most of the water harvesting structures are already much older than 50 years and originate even from Roman or Arab times.

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

Comentários:

Major land use problems (compiler’s opinion): There is a lack of water for irrigation of crops limiting the crop types that can be planted as well as the crop yield of dryland farming. A lack of water availability seriously limits the production potential of the soil and results in a low vegetation/crop cover. The relatively high soil erosion rates cause various off-site related problems (i.e. flooding, reservoir siltation) and on-site problems (i.e. gully formation and loss of soil depth).

Major land use problems (land users’ perception): Lack of water for irrigation of crops limiting the crop types that can be planted as well as the crop yield of dryland farming.

Livestock is grazing on crop residues

3.3 Mais informações sobre o uso da terra

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

• Precipitação natural

Número de estações de cultivo por ano:

• 1

Especifique:

Longest growing period in days: 220Longest growing period from month to month: november until June

3.4 Grupo de GST ao qual pertence a tecnologia

• Coleta de água

3.5 Difusão da tecnologia

Especifique a difusão da tecnologia:

• Uniformemente difundida numa área

Caso a tecnologia seja uniformemente difundida numa área, indique a área coberta aproximada:

• < 0,1 km2 (10 ha)

Comentários:

The exact area is not known. Traditionally the technology was common throughout the province of Murcia and the district of the upper Guadalentin, now most are abandoned and destroyed.

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: Ha: aridification

Secondary types of degradation addressed: Wo: offsite degradation effects

Main causes of degradation: droughts (Dry periods and dry years require higher water availability)

Secondary causes of degradation: crop management (annual, perennial, tree/shrub) (Large areas without a protective vegetation cover cause increased runoff and erosion rates and facilitat flash floods), over abstraction / excessive withdrawal of water (for irrigation, industry, etc.) (Over-abstraction leads to a lowering of the water table. Therefore additional aquifer abstraction is not allowed by water authority.), Heavy / extreme rainfall (intensity/amounts) (Extreme rainfall causes flash floods with high water losses and low effectiveness for crop production.)

3.8 Redução, prevenção ou recuperação da degradação do solo

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

• Prevenir degradação do solo
• Reduzir a degradação do solo

Comentários:

Main goals: prevention of land degradation, mitigation / reduction of land degradation

4.1 Desenho técnico da tecnologia

4.2 Especificações técnicas/ explicações do desenho técnico

Sketch of a water harvesting structure consisting of an earthen- or stone- built dyke that diverts water into cultivated fields. Several terraces are present in the fields in order to reduce slope gradient and retain water longer within the fields to allow maximum infiltration. Depending on the expected inflow of water several spillways can be made per terrace to prevent excessive concentration of flow in each spillway.

Technical knowledge required for field staff / advisors: moderate (Selection of the proper location and assessment of up- and downstream linkages.)

Technical knowledge required for land users: low (Practical implementation of the water harvesting structure does not require a high level of knowledge)

Main technical functions: control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, increase of infiltration, water harvesting / increase water supply

Secondary technical functions: increase of groundwater level / recharge of groundwater, water spreading

Spillway
Spacing between structures (m): 50
Depth of ditches/pits/dams (m): 0.5
Width of ditches/pits/dams (m): 1-3

Structural measure: water harvest dyke
Depth of ditches/pits/dams (m): <1
Width of ditches/pits/dams (m): <2
Length of ditches/pits/dams (m): <50

Construction material (earth): Soil from the stream banks is used to built the dyke and provide an opening into the cultivated fiel

Construction material (stone): Stones are used to fortify the dyke and spillways against the impact of flow.

Construction material (concrete): Potentially concrete is used to fortify the dyke and spillways against the impact of flow.

Specification of dams/ pans/ ponds: Capacity 5m3

Catchment area: >0.5km2m2

Beneficial area: 1-2 ham2

Slope of dam wall inside: 100%;
Slope of dam wall outside: 100%

Dimensions of spillways: 1-3m wide and <50 cm deep

4.3 Informação geral em relação ao cálculo de entradas e custos

Outro/moeda nacional (especifique):

EURO

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

0,63

4.4 Atividades de implantação

	Atividade	Tipo de medida	Periodicidade
1.	Construction of a dyke (dam)	Estrutural	summer or winter

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	5 meter dyke	1,0	150,0	150,0	100,0
Equipamento	Machine use	5 meter dyke	1,0	350,0	350,0	100,0
Material de construção	Concrete	5 meter dyke	1,0	400,0	400,0	100,0
Custos totais para a implantação da tecnologia					900,0

Comentários:

Duration of establishment phase: 1 month(s)

4.6 Atividades recorrentes/manutenção

	Atividade	Tipo de medida	Periodicidade/frequência
1.	restoration of the dyke	Estrutural	once in 5 yr (after important events)

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	5 meter dyke	1,0	4,0	4,0	100,0
Equipamento	Machine use	5 meter dyke	1,0	12,0	12,0	100,0
Material de construção	Concrete	5 meter dyke	1,0	25,0	25,0	100,0
Custos totais para a manutenção da tecnologia					41,0

Comentários:

Machinery/ tools: For construction and maintenance of the dyke tractor or small bulldozer is required.

The costs were indicated assuming a length of the bund dimensions of 5*1*1 metres. Maintenance is required once every 5 years, so yearly costs are the total costs divided by 5 (Prices are for spring 2008).

4.8 Fatores mais importantes que afetam os custos

Descreva os fatores mais determinantes que afetam os custos:

Labour costs and price of concrete are the most determinate factors affecting the costs.

5.1 Clima

5.2 Topografia

Indique se a tecnologia é aplicada especificamente em:

• Posições côncavas

Comentários e outras especificações sobre a topografia:

Landforms: Valley floors (mostly concave slope section)

5.3 Solos

5.4 Disponibilidade e qualidade de água

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

Ground water table: >50m (There is a lowering of groundwater table due to overexploitation for irrigation purposes)
Availability of surface water: Poor/none. Sporadically excess when there are flash floods during extreme rainfall events
Water quality (untreated) For agricultural use only (irrigation)(groundwater)

5.5 Biodiversidade

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
Difference in the involvement of women and men: Traditionally most agriculture is done by men in this region.
Population density: 10-50 persons/km2
Annual population growth: < 0.5%
15% of the land users are rich and own 20% of the land.
80% of the land users are average wealthy and own 75% of the land.
5% of the land users are poor and own 5% of the land.
Off-farm income specification: There is no difference in the ones who apply the technology and those who don’t. Most farmers do have an off-farm income for example from hunting, work in a factory, or office.

Market orientation: Commercial/market or mixed (subsistence and commercial)(some farmers are weekend or hobby farmers and not market oriented)

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:

• Estado
• Indivíduo, intitulado

Direitos do uso da terra:

• Comunitário (organizado)
• Indivíduo

Direitos do uso da água:

• Comunitário (organizado)
• Indivíduo

Comentários:

Most land is privately owned. The streams are not privately owned. Therefore permits are required to construct a water harvesting structure. Some shrubland or forest is state property. Water rights are provided and controlled by the Water authority of the Segura river basin (CHS).

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

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	não 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)	não bem

Outras consequências relacionadas ao clima

Outras consequências relacionadas ao clima

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

Comentários:

The crop type is sensitive to changes in water availability under the semi arid conditions.

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:

Implementation of the technology is relatively expensive. Once installed, maintenance is not expensive and pays off because of higher productivity.

6.5 Adoção da tecnologia

Entre todos aqueles que adotaram a tecnologia, quantos adotaram espontaneamente, ou seja, sem receber nenhum incentivo material/pagamentos?

• 90-100%

Comentários:

100% of land user families have adopted the Technology without any external material support

There is no trend towards spontaneous adoption of the Technology

Comments on adoption trend: Much of this knowledge is forgotten and not applied or maintained anymore.

6.7 Pontos fortes/vantagens/oportunidades da tecnologia

Pontos fortes/vantagens/oportunidades na visão do usuário da terra
The extra input of free water allows higher crop productivity.

Pontos fortes/vantagens/oportunidades na visão do/a compilador/a ou de outra pessoa capacitada
This technology is very effective at increasing water available for crop production and so increasing crop yield and farm income How can they be sustained / enhanced? Temporarily store the harvested water in a cistern to be used for irrigation using drip irrigation when most needed.
The technology takes advantage of floodwater that is otherwise lost because of the erratic character and short duration of flow How can they be sustained / enhanced? Finding the optimal location for the water harvesting structures using a modelling approach

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?
Farmers consider it relatively expensive to implement and there is no guarantee for water as this depends on the rainfall events.	Subsidies might help to install these structures where feasible. Therefore, good assessments of expected water inflow volumes are required before construction

Pontos fracos/vantagens/riscos na visão do/a compilador/a ou de outra pessoa capacitada	Como eles podem ser superados?
The implementation costs are relatively high when the bunds are made of concrete	Use of cheap materials that are freely available (stones from the fields). However, it is important to make the structure as resistant as possible against flood events.
The water provided by these techniques is mostly interesting for small- and medium- scale rainfed farming. Intensively irrigated farming requires more water and a guarantee for water independently of flood events	Intensively irrigated farming might use this technology as an additional source of water and may store the harvested water in a cistern for use when needed.

7.2 Referências às publicações disponíveis

Título, autor, ano, ISBN:

rot, E., van Wesemael, B., Benet, A.S. and House, M.A., 2008. Water harvesting potential in function of hillslope characteristics: A case study from the Sierra de Gador Journal of Arid Environments 72(7):1213-1231

Disponível de onde? Custos?

Internet

Título, autor, ano, ISBN:

Giráldez, J.V., Ayuso, J.L., Garcia, A., López, J.G. and Roldán, J., 1988. Water harvesting strategies in the semiarid climate of southeastern Spain. Agricultural Water Management, 14(1-4): 253-263.

Disponível de onde? Custos?

Internet

Título, autor, ano, ISBN:

Hooke, J.M. and Mant, J.M., 2002. Floodwater use and management strategies in valleys of southeast Spain. Land Degradation & Development, 13(2): 165-175.

Disponível de onde? Custos?

Internet

Título, autor, ano, ISBN:

López-Gálvez, J. and Losada, A., 1998. EVOLUCIÓN DE TÉCNICAS DE RIEGO EN EL SUDESTE DE ESPAÑA. Ingeniería del Agua, 5(3): 41-50.

Disponível de onde? Custos?

Internet

Título, autor, ano, ISBN:

Nasri, S., Albergel, J., Cudennec, C. and Berndtsson, R., 2004. Hydrological processes in macrocatchment water harvestingin the arid region of Tunisia: the traditional system of tabias. Hydrological Sciences-Journal, 49(2): 261-272.

Disponível de onde? Custos?

Internet

Título, autor, ano, ISBN:

van Wesemael, B., et al., 1998. Collection and storage of runoff from hillslopes in a semi-arid environment: geomorphic and hydrologic aspects of the aljibe system in Almeria (Spain). Journal of Arid Environments 40(1):1-14

Disponível de onde? Custos?

Internet

Título, autor, ano, ISBN:

Greenpeace, 2007. El negocio del agua en la cuenca del Segura, Greenpeace.

Disponível de onde? Custos?

www.greenpeace.es