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

Nom du projet qui a facilité la documentation/ l'évaluation de la Technologie (si pertinent)

Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )

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

Technical University of Crete (Technical University of Crete) - Grèce

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

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

06/03/2015

Le compilateur et la(les) personne(s) ressource(s) acceptent les conditions relatives à l'utilisation par WOCAT des données documentées:

Oui

1.4 Déclaration sur la durabilité de la Technologie décrite

Est-ce que la Technologie décrite ici pose problème par rapport à la dégradation des terres, de telle sorte qu'elle ne peut pas être déclarée comme étant une technologie de gestion durable des terres?

Non

2.1 Courte description de la Technologie

Définition de la Technologie:

Rain water harvesting from greenhouses roofs.

2.2 Description détaillée de la Technologie

Description:

The roof of a greenhouse is used as catchment area for rainwater harvesting. A system of gutters is installed to channel water into a storage facility that can be either above ground or at ground level, open or covered. The water harvested from the roofs is used for irrigation purposes, either on its own or mixed with other sources.

In central and eastern Crete, a negative water balance emerges due to agricultural exploitation and lack of sustainable water resources management. Regarding water availability, it is notable that the spatial and temporal variability of precipitation are the limiting factors, rather than overall precipitation quantity. Especially in coastal areas where the main source of irrigation is groundwater, seawater intrusion often takes place, and eventually leading to irrigation with saline water. In the intensive agriculture and water stress conditions existing in greenhouses this situation can progressively lead to soil salinisation with subsequent adverse effects on production. The technology promotes sustainable land management through prevention and mitigation of land degradation by increasing water resources self-sufficiency thus allowing the user to rely less on the scarce groundwater resources and reduce the risk of production failure. Furthermore, the technology improves the overall irrigation water quality. The main disadvantage of the technology is the increase of agricultural inputs (fertilizers) because of the lack of minerals necessary for the crops (especially tomatoes) in the rainwater. This disadvantage can be mitigated by mixing rainwater with other sources.

The majority of the greenhouses in the region normally have built-in gutters between the basic construction units in order to discharge rainwater from the roof for structural safety. Thus, initially little structural measures are required including the implementation of some further gutters that channel rainwater in the storage system and preparation of the area for the tank installation. Overland tanks may consist of galvanized steel or similar material. Ground level storage usually requires earth removal. In both case, the installation of the relevant waterproofing material is required to avoid leaks. A cover may also be installed to reduce evaporation. Here we assess the use of a harvesting system comprising of (a) an above ground circular tank made out of galvanized steel with total volume of 320 m3 and (b) a gutter network spreading on the roof of a 0.7 ha greenhouse. Furthermore, a water filter and water treatment may be required for removal of particles and waterborne disease mitigation. Finally, a suitable pump and mixing facilities are installed to control water quality and quantity.

The average annual precipitation in the area is 500 mm and the climate ranges between sub-humid Mediterranean and semi-arid. Average annual temperature is 18.5 °C with 6 months below 18 °C but above 5 °C, thus classifying the area as subtropical. In the location where the technology is applied, land is mostly privately owned and water rights can be public, cooperative or private. Although the financial means of the land user who applies this technology are more or less on par with those of the rest of the community, he has a wider empirical education and relatively higher social status acquired thought his involvement with the commons and the water resources management of the region.

This Technology was documented within the scope of FP7 RECARE Project, funded grant agreement no 603498.

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 entre 10-50 ans

2.7 Introduction de la Technologie

Spécifiez comment la Technologie a été introduite: :

• par le biais de projets/ d'interventions extérieures

Commentaires (type de projet, etc.) :

The land user has implemented the water harvesting technology in order to be subsidized from an agri-environmental scheme under the CAP.

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

Commentaires:

Major land use problems (compiler’s opinion): The main problem in the region is the change in the groundwater quality, caused by groundwater over-exploitation and the subsequent seawater intrusion, resulting in soil salinisation through irrigation.
Major land use problems (land users’ perception): The limited availability of good quality (non-saline) water for irrigation resulting in increased production risk and agricultural inputs.

3.3 Informations complémentaires sur l'utilisation des terres

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

• pleine irrigation

Nombre de période de croissance par an: :

• 1

Précisez:

Longest growing period in days: 270, Longest growing period from month to month: October to June

3.4 Groupe de GDT auquel appartient la Technologie

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

3.5 Diffusion de la Technologie

Commentaires:

Total area covered by the SLM Technology is 0.007 m2.

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Main measures: structural measures
Specification of other structural measures: Greenhouse roof gutter network

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

Main type of degradation addressed: Cs: salinisation / alkalinisation, Hg: change in groundwater / aquifer level
Secondary types of degradation addressed: Bq: quantity / biomass decline
Main causes of degradation: over abstraction / excessive withdrawal of water (for irrigation, industry, etc.) (Overpumping.), other human induced causes (specify) (Irrigation with brackish water.), droughts (Lack of sustainable water resources.), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (Poor coverage of freshwater irrigation network.)
Secondary causes of degradation: soil management (Intensive cultivation), disturbance of water cycle (infiltration / runoff) (Covering of land with green houses decreases leaching.)

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:

• prévenir la dégradation des terres
• réduire la dégradation des terres

4.1 Dessin technique de la Technologie

4.2 Spécification/ explications techniques du dessin technique

A network of gutters channels rainwater to an adequately insulated metal tank. The stored water is then used for irrigation.

Location: Timpaki. Heraklion, Crete, Greece
Date: 31/3/2015

Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: moderate
Main technical functions: water harvesting / increase water supply, improvement of water quality, buffering / filtering water
Secondary technical functions: increase of groundwater level / recharge of groundwater

Dam/ pan/ pond
Height of bunds/banks/others (m): 2.7
Width of bunds/banks/others (m): 12.3

Structural measure: gutter network
Length of bunds/banks/others (m): 210

Construction material (other): Plastic gutters on the greenhouses roofs, galvanized steel & wateproof membrane for the tank
Specification of dams/ pans/ ponds: Capacity 320m3
Catchment area: 7000m2m2
Beneficial area: 7000m2m2

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

autre/ monnaie nationale (précisez):

Euro

Indiquer le taux de change du dollars en monnaie locale (si pertinent): 1 USD= :

0,93

4.4 Activités de mise en place/ d'établissement

	Activité	Type de mesures	Calendrier
1.	Construction of the tank base (including material transportation)	Structurel
2.	Tank construction (including material transportation)	Structurel
3.	Installation of the plastic gutters	Structurel
4.	Pump and cleaning filter	Structurel

4.5 Coûts et intrants nécessaires à la mise en place

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% des coût supporté par les exploitants des terres
Main d'œuvre	Labour		1,0	858,0	858,0	60,0
Equipements	pump		1,0	536,0	536,0	60,0
Equipements	cleaning filter		1,0	536,0	536,0	60,0
Matériaux de construction	galvanized steel		1,0	3379,0	3379,0	60,0
Matériaux de construction	waterproof membrane		1,0	2360,0	2360,0	60,0
Matériaux de construction	sand		1,0	675,0	675,0	60,0
Matériaux de construction	concrete		1,0	290,0	290,0	60,0
Autre	gutters		1,0	2252,0	2252,0	60,0
Coût total de mise en place de la Technologie					10886,0

Commentaires:

Duration of establishment phase: 0.5 month(s)

4.6 Activités d'entretien/ récurrentes

	Activité	Type de mesures	Calendrier/ fréquence
1.	Maintenance costs are negligible, e.g. filters are cleaned with water when needed. Fuel can't be accurately estimated as it depends on the machine hours that the pump works to irrigate. Two considerations: 1. Practically, the pump would have to work regardless of the water harvesting system. 2. The water harvesting system is irrelevant of the pumping scheme.	Structurel

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

Commentaires:

The cost described are calculated in current prices for the whole construction.

4.8 Facteurs les plus importants affectant les coûts

Décrivez les facteurs les plus importants affectant les coûts :

The greater deterrent against implementing the technology is the high cost of the tank construction.

5.1 Climat

5.2 Topographie

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 characterized mainly as sandy clay loam or clay loam

5.4 Disponibilité et qualité de l'eau

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

Water quality (treated): good drinking water

5.5 Biodiversité

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
Population density: 10-50 persons/km2
Annual population growth: 1% - 2%

5.7 Superficie moyenne des terres détenues ou louées par les exploitants appliquant la Technologie

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

Propriété foncière:

• individu, avec titre de propriété

Droits d’utilisation des terres:

• loué
• individuel

• Cooperative

Droits d’utilisation de l’eau:

• communautaire (organisé)
• individuel

• Cooperative

5.9 Accès aux services et aux infrastructures

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Production

Revenus et coûts

Autres impacts socio-économiques

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

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	Type de changements/ extrêmes climatiques	Comment la Technologie fait-elle face à cela?
températures annuelles		augmente	bien

Extrêmes climatiques (catastrophes)

Catastrophes climatiques

	Comment la Technologie fait-elle face à cela?
sécheresse	pas bien

Autres conséquences liées au climat

Autres conséquences liées au climat

	Comment la Technologie fait-elle face à cela?
Decrease of water temperature	pas bien

Commentaires:

The optimum water temperature for the crops cultivated in the greenhouse (tomatoes) is about 20 °C. If water temperature is less than 14 °C then the land user has to rely on an alternative source.

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:

In the long term soil health is greatly maintained.

6.5 Adoption de la Technologie

• plus de 50%

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

70% or 7 land user families

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:

30% of land user families have adopted the Technology without any external material support
3 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: Land users are probably not able to afford or justify the cost without external material support.
There is a little trend towards spontaneous adoption of the Technology
Comments on adoption trend: Word of mouth conveys the successful results and several users are eager to adopt the technology but not without external material support.

6.7 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue de l'exploitant des terres
Increased irrigation water availability, and security; reduced crop failure risk; ability to diversify or intensify production

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
Self-sufficiency of water; sustainable agriculture management (soil protection and conservation) and reduced failure risk; decreased soil salinity

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?
High construction cost.	The construction of a water harvesting system for greenhouses can be subsidized.
Tomato cultivation requires water with higher electric conductivity than that of rainwater, therefore increased agricultural inputs may be required to treat the harvested rainwater.	Rainwater may be mixed with brackish water at a prescribed ratio.

Faiblesses/ inconvénients/ risques du point de vue du compilateur ou d'une autre personne ressource clé	Comment peuvent-ils être surmontés?
Is dependent on climatic conditions (precipitation/evaporation)	During dry years the storage tank can be used as a buffer from other sources. Installing a cover reduces evaporation.
High construction cost.	The construction of a water harvesting system for greenhouses can be made obligatory.
The storage area decreases the area available for cultivation (or can't be established in very small properties)

7.1 Méthodes/ sources d'information