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

Nombre del proyecto que financió la documentación/ evaluación de la Tecnología (si fuera relevante)

Book project: Making sense of research for sustainable land management (GLUES)

Nombre de la(s) institución(es) que facilitaron la documentación/ evaluación de la Tecnología (si fuera relevante)

University of Oldenburg (University of Oldenburg) - Alemania

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

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

10/06/2015

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:

Water retaining polders to reduce flood risk due to heavy rainfall or runoff at high tide in embanked coastal lowlands. Delineation of the retention area and land use within the retention area was developed in a participatory process with local experts.

2.2 Descripción detallada de la Tecnología

Descripción:

In the 19th and 20th century land was reclaimed from the sea to make use of the exposed fertile soils for agriculture through a process known as ‘impoldering’. The reclaimed land is now characterized by intensive grazing and cropland. This is a region where agriculture is the most important form of land use. However, the land needs to be regularly drained. Given the expected increase in precipitation in winter due to climate change, the corresponding increase in freshwater discharge needs to be managed. Furthermore, the periods when natural discharge into the sea oc-curs are likely to decrease – because of rising sea levels also caused by climate change. Consequently, in winter and spring, greater quantities of freshwater will need to be pumped into the sea rather than discharged naturally at the low or ‘ebb’ tide. Specially embanked water retention polders will be required to temporarily impound water as part of a multifunctional approach to coastal zone management.

Purpose of the Technology: These retention polders could be a cost-effective alternative to expensive invest-ments in extra pumping capacities to prevent submergence of low-lying cultivated areas. The primary aim is to restrict floods to the retention polders when the drain-age network is overburdened and cannot deal with the predicted extra demands in the future. The high evapotranspiration from the open waterbody, and the reeds growing within, will also help with reducing the amount of water. During dry sum-mers, the water in the retention polder could also be put to creative use as a source of irrigation. Another potential advantage is that subsurface saltwater intrusion in the region could be prevented by the freshwater-filled polders. During extreme storm surges and in the rare case of breaches in the sea wall, the retention polders would serve as an extra line of defence by holding seawater.

Establishment / maintenance activities and inputs: An embankment enclosing approx. 500 ha will be able to store up to 2,500,000 m³ of water. This will improve the drainage of an area of approx. 49,000 ha. The invest-ment for building this water retention area is high – but for the reasons stated it serves a necessary purpose at a cost which is lower than the alternative – increased pumped drainage installations. Maintenance costs will be lower than the drainage alternative as only the integrity of the embankment needs to be monitored regularly. Currently, agricultural land use within the polders is adapted to higher water levels and occasional flooding. Within the embanked area there will be a change from the current use of mainly crop land to extensive grazing, open water and reed stands.

Natural / human environment: Some parts within the retention polder will be used for agricultural purposes, while the wetter parts will be set aside. In these latter sections, undisturbed natural regen-eration will take place. A landscape comprising various different elements, without any extreme forms of intensive land use such as large areas of monocultures will be the result. Thus requirements for agricultural use and tourism will be addressed.

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:

• 10-50 años atrás

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• durante experimentos/ investigación
• mediante proyectos/ intervenciones externas

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

Comentarios:

Major land use problems (compiler’s opinion): Flood events and droughts may substantially disrupt the contemporary land use in the future and lead to higher drainage costs and higher economic risks for agricultural production. This may reduce the ecological and economic viability of the current intensive and highly productive land use under a changing climate.

Major land use problems (land users’ perception): There is no awareness of risks due to climate change in the land users point of view.

Cut-and-carry/ zero grazing: cows for milk

Improved pasture: cattle for milk and meat

Future (final) land use (after implementation of SLM Technology): Other: Oo: Other: wastelands, deserts, glaciers, swamps, recreation areas, etc

Constraints of infrastructure network (roads, railways, pipe lines, power lines): needs to be adapted to regular flooding

Constraints of recreation (landscape is used for recreation and tourism ): change in landscape due to retention area

Constraints of nature conservation area (protected sites): wetter conditions in retention area

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.

Mixed: Mp: Agro-pastoralism

3.3 Información adicional sobre el uso de tierras

Comentarios:

Water supply: rainfed, mixed rainfed - irrigated

Número de temporadas de cultivo por año:

• 1

Especifique:

Longest growing period in days: 240Longest growing period from month to month: March to October

Densidad del ganado (si fuese relevante):

> 100 LU /km2

3.4 Grupo MST al que pertenece la Tecnología

• manejo de agua superficial (manantial, río, lagos, mar):
• protección/manejo de humedales

• Flood prevention

3.5 Difusión de la Tecnología

Comentarios:

Total area covered by the SLM Technology is 33.7 m2.

3.6 Medidas MST que componen la Tecnología

Comentarios:

Main measures: structural measures

Secondary measures: management measures

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

Main type of degradation addressed: Hs: change in quantity of surface water

Secondary types of degradation addressed: Cs: salinisation / alkalinisation, Hg: change in groundwater / aquifer level, Hq: decline of groundwater quality

Main causes of degradation: change of seasonal rainfall (Climate change, higher rainfall in winter, lower in summer), Heavy / extreme rainfall (intensity/amounts) (Heavy rainfall in winter due to climate change expected), floods (Flooding due to heavy rainfall in winter)

Secondary causes of degradation: droughts (Droughts due to less rainfall in summer (climate change)), other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify (Sea level rise)

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:

• prevenir la degradación del suelo
• reducir la degradación del suelo

Comentarios:

Main goals: prevention of land degradation

Secondary goals: mitigation / reduction of land degradation

4.1 Dibujo técnico de la Tecnología

4.2 Especificaciones técnicas/ explicaciones del dibujo técnico

The figure shows the study region, located on the North Sea coast. The whole area is protected by a sea wall (grey). Crop fields (yellow), grasslands (green) and the drainage system (light blue) char-acterize the region. In contrast to T_GER001en and T_GER002en small water bodies (blue) surrounded by reeds (brown) act as water retention polders. Agricultural land use in some retention areas is adapted to the ground water levels and flooding frequencies. This results in parts of the retention areas being taken out of agricultural production and undisturbed development of natural habitats occurring. In other parts of the retention areas extensive grazing or reed farming will be practiced. This leads to a mosaic of different land uses in the landscape. Retention areas of 500 ha are able to store up to 2,500,000 m³ water. The height of the dams depends on the elevation of the landscape but in general a height of less than 2 m is sufficient.

Location: Krummhörn. County of Aurich, Lower Saxony

Technical knowledge required for field staff / advisors: high (To generate income in the retention area (without existing agricultural methods))

Technical knowledge required for water board: high (To build a new adapted drainage system with retention areas)

Main technical functions: control of dispersed runoff: retain / trap, control of concentrated runoff: retain / trap

Secondary technical functions: increase / maintain water stored in soil, increase of groundwater level / recharge of groundwater, spatial arrangement and diversification of land use

Dam/ pan/ pond
Height of bunds/banks/others (m): 1
Width of bunds/banks/others (m): 2
Length of bunds/banks/others (m): 13000

Construction material (earth): sand core and clay cover

Specification of dams/ pans/ ponds: Capacity 2500000m3

Catchment area: 49000ham2

Beneficial area: 49000ham2

Other specifications: size of retention area (embanked area): 500.00 ha

Change of land use type: Within the retention area the conditions are wetter than before. Therefore the agricultural land use needs to be changed to an adapted land use.

Change of land use practices / intensity level: Under the wetter conditions only a less intensive land use is possible, e.g. no crop fields but instead extensive grazing or cessation of agricultural land use.

4.3 Información general sobre el cálculo de insumos y costos

otra / moneda nacional (especifique):

Euro

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

0,94

4.4 Actividades de establecimiento

	Actividad	Tipo de medida	Momento
1.	Building of dams	Estructurales	during winter months

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	Labour	Dam	1,0	10000000,0	10000000,0
Equipo	Machine use	Dam	1,0	4000000,0	4000000,0
Material de construcción	Earth	Dam	1,0	112000,0	112000,0
Costos totales para establecer la Tecnología					14112000,0

Comentarios:

Duration of establishment phase: 3 month(s)

4.6 Actividades de establecimiento/ recurrentes

	Actividad	Tipo de medida	Momento/ frequencia
1.	Control of dams	Estructurales	once a year
2.	Maintenance of dams	Estructurales	once a year
3.	Maintenance of drainage system	Estructurales	once a year (mean of many years)

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	Labour	Dam	1,0	500,0	500,0
Equipo	Machine use	Dam	1,0	200,0	200,0
Material de construcción	Earth	Dam	1,0	100,0	100,0
Otros	Maintenance per km ditch	Dam	1,0	2270,7	2270,7
Indique los costos totales para mantenecer la Tecnología					3070,7

Comentarios:

Machinery/ tools: digger, open truck

The main investment is based on a dam length of 13 km to build up the retention area of a size of 500 ha. The length of the drainage network for the whole watershed (retention area and the surroundings) is 1,134 km. Maintenance costs of drainage network are based on long term annual mean cost of 2,270.72 Euro per km including pumping costs.

4.8 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

The establishment costs are for the whole retention area (500 ha). The establishment period will be half a year.
Mainly the elevation in the region determines the costs as the height of the dams depend on the elevation. Typical heights are 1 m up to 2 m with a slope of 1:3.

5.1 Clima

5.2 Topografía

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 fertility is high
Soil drainage/infiltration is meidum
Soil water storage capacity is high

5.4 Disponibilidad y calidad de agua

5.5 Biodiversidad

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

Population density: 50-100 persons/km2

Annual population growth: < 0.5%

1% of the land users are very rich and own 1% of the land.
49% of the land users are rich and own 24% of the land.
50% of the land users are average wealthy and own 50% of the land.
and own 25% of the land.

Off-farm income specification: Many farmers do additional work in companies

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:

• individual, sin título

Derechos de uso de tierra:

• individual

5.9 Acceso a servicios e infraestructura

6.1 Impactos in situ demostrados por la Tecnología

Impactos socioeconómicos

Producción

Ingreso y costos

Otros impactos socioeconómicos

Impactos socioculturales

Impactos ecológicos

Ciclo de agua/ escurrimiento de sedimento

Suelo

Biodiversidad: vegetación, animales

Reducción de riesgos de desastres y riesgos climáticos

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	bien
tormenta de viento	bien

Desastres climatológicos

	¿Cómo es que la tecnología soporta esto?
sequía	bien

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

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 benefits will be visible in an longer time frame. There will be benefits of the investments when considering sea level rise in the upcoming 100 years.

6.5 Adopción de la Tecnología

Comentarios:

Comments on spontaneous adoption: The SLM Technology is not implemented by land users but needs to be implemented in spatial planning of the federal state. We expect that there is a chance for implementation.

There is a strong trend towards spontaneous adoption of the Technology

Comments on adoption trend: The SLM Technology was developed together with regional experts. It seems that the ideas developed, merge more often in their recent discussion and an implementation is likely.

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del usuario de la tierra
The retention area will supplement the drainage of the arable fields and pastures outside the retention area How can they be sustained / enhanced? Combine with other technical solutions for protection against flooding.

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave
Prevention of flooding during strong rainfalls and possibility to irrigate during dry periods How can they be sustained / enhanced? The larger the retention areas are the more water can be stored
Prevention of salt water intrusion in the region How can they be sustained / enhanced? Fresh water in the retention areas prevents saline ground water from intrusion. Build polders in areas where saline ground water intrudes.
Endangered species might obtain new habitats in the retention area How can they be sustained / enhanced? Extensive land use can help to optimize the habitats for endan-gered species and increase attractiveness for tourism.
Through investments in building retention polders the very ex-pensive strengthening of the existing drainage system is no longer necessary. How can they be sustained / enhanced? By increasing the attractiveness for tourism alternative benefits for land owner can be generated.
Multi-functional land use in the catchment and in the retention area How can they be sustained / enhanced? Support farmers with land in the retention area (e.g. financially or with additional agricultural land outside the retention area). Sup-port discussions between farmers’ associations and nature con-servation agencies.

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 retention polders will change the landscape and this may reduce the value of the region for tourism	Include tourist concerns within the retention area (accessibility, information, attractiveness)
Endangered species might lose habitats when building up the retention polders	Do not build a retention area where endangered species live
Loss of livelihoods	Retention areas should be planned for parts of the landscape without settlements

Debilidades/ desventajas/ riesgos desde la perspectiva del compilador o de otra persona de referencia clave	¿Cómo sobreponerse a ellas?
Loss of land for agricultural production	Create retention polders where the productivity is already low. Encourage alternative land use (for example reed production) in the retention polders.
High water levels (especially with changing levels) may generate high emissions of greenhouse gases.	Ground water levels should kept stable near to the soil surface.
Retention area is probably too small if pessimistic sea level rise predictions come true.	Increase size of retention polders.

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

http://www.comtess.uni-oldenburg.de/

7.3 Vínculos a la información relevante disponible en línea

Título/ descripción:

http://www.comtess.uni-oldenburg.de/