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)

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

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

University of Oldenburg (University of Oldenburg) - Alemanha

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

Quando os dados foram compilados (no campo)?

09/06/2015

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 retention polders to reduce flood risk due to heavy rainfall or runoff at high tide in coastal lowlands. The retention polders are used to accumulate organic material for climate change mitigation and enable development of undisturbed natural habitats, rather than for agriculture.

2.2 Descrição detalhada da tecnologia

Descrição:

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. 3,000 ha will be able to store up to 25,000,000 m³ 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. However within the proposed retention polders – the areas enclosed by the em-bankment - no agricultural activity will take place. This will lead to a change from the current intensive grazing for dairy farming and cropland to non-agricultural use. And therefore a development towards swamps, reed stands and open waters will take place. It is expected that a development to undisturbed natural habitats will increase the number of endangered species. There will be an accumulation of or-ganic material (and organic carbon) in the form of peat due to the wet conditions within the retention polders. Carbon will be sequestered by plant growth and thus reduce the amount of CO2 in the atmosphere. The natural regeneration within the embanked areas will be attractive for tourism and recreation, which should provide an opportunity for additional income generation for the local population.

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:

• durante experiências/ pesquisa
• através de projetos/intervenções externas

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

Comentários:

Major land use problems (compiler’s opinion): Flood events and droughts may substantially disrupt the current land use system in the future and lead to higher drainage costs and higher economic risks for agricultural production. This will 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.

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 reacreation and tourism): change in landscape due to retention area

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

Caso o uso da terra tenha mudado devido a implementação da tecnologia, indique seu uso anterior à implementação da tecnologia:

Mixed: Mp: Agro-pastoralism

3.3 Mais informações sobre o uso da terra

Comentários:

Water supply: rainfed, mixed rainfed - irrigated

Número de estações de cultivo por ano:

• 1

Especifique:

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

Densidade animal (se relevante):

> 100 LU /km2

3.4 Grupo de GST ao qual pertence a tecnologia

• Gestão de água de superfície (nascente, rio, lagos, mar)
• Gestão/proteção de zonas úmidas

• Flood prevention

3.5 Difusão da tecnologia

Comentários:

Total area covered by the SLM Technology is 33.7 m2.

3.6 Medidas de GST contendo a tecnologia

Comentários:

Main measures: structural measures

Secondary measures: management measures

3.7 Principais tipos de degradação da terra abordados pela tecnologia

Comentários:

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 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

Secondary goals: mitigation / reduction of land degradation

4.1 Desenho técnico da tecnologia

4.2 Especificações técnicas/ explicações do desenho 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. Large water bodies (blue) sur-rounded by reeds (brown) act as water retention polders. Vegetative regeneration, build-up of peat and re-establishment of natural habitats occurs within the retention polders. The land around the retention polders (the higher parts of the land-scape) profits from the retention areas as the risk of flooding is reduced and can be used for cropland and intensive grazing. Depending on the size of the retention area a huge amount of excess water can be contained. Retention areas of 3,000 ha are able to store up to 25,000,000 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 in organic matter, increase / maintain water stored in soil, increase of groundwater level / recharge of groundwater

Dam/ pan/ pond
Height of bunds/banks/others (m): 1
Width of bunds/banks/others (m): 2
Length of bunds/banks/others (m): 30000

Construction material (earth): sand core and clay cover

Specification of dams/ pans/ ponds: Capacity 25000000m3

Catchment area: 49000ham2

Beneficial area: 49000ham2

Other specifications: size of retention area (embanked area): 3,000.00 ha

Change of land use type: The former pastures and crop fields will not be used any more. Cessation of land use will take place.

Change of land use practices / intensity level: No more agricultural land use within the retention areas. The wetter conditions will lead to peat accumulation

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 =:

0,94

4.4 Atividades de implantação

	Atividade	Tipo de medida	Periodicidade
1.	Building of dams	Estrutural	during winter months

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	Dam	1,0	21000000,0	21000000,0
Equipamento	Machine use	Dam	1,0	9000000,0	9000000,0
Material de construção	Earth	Dam	1,0	750000,0	750000,0
Custos totais para a implantação da tecnologia					30750000,0

Comentários:

Duration of establishment phase: 3 month(s)

4.6 Atividades recorrentes/manutenção

	Atividade	Tipo de medida	Periodicidade/frequência
1.	Control of dams	Estrutural	once a year
2.	Maintenance of dams	Estrutural	once a year
3.	Maintanance of drainage system	Estrutural	once a year

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	Dam	1,0	800,0	800,0
Equipamento	Machine use	Dam	1,0	300,0	300,0
Material de construção	Earth	Dam	1,0	100,0	100,0	1,0
Outros	Maintenance per km ditch	Dam	1,0	2270,7	2270,7
Custos totais para a manutenção da tecnologia					3470,7

Comentários:

Machinery/ tools: digger, open truck

The main investment is based on a dam length of 30 km to build up the retention area of a size of 3 000 ha. The length of the drainage network for the whole watershed is 1,074 km. Within the retention area no maintenance of the drainage network is necessary as there is no agricultural land use and drainage is not maintained any more. 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 Fatores mais importantes que afetam os custos

Descreva os fatores mais determinantes que afetam os custos:

The establishment costs are for the whole retention area (3 000 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 Topografia

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 fertiliuty is high
Soil drainage/infiltration is medium
Soil water storage capacity is high

5.4 Disponibilidade e qualidade de água

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

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.
50% 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 industry or servicing sector

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, não intitulado

Direitos do uso da terra:

• Indivíduo

5.9 Acesso a serviços e infraestrutura

6.1 Impactos no local mostrados pela tecnologia

Impactos socioeconômicos

Produção

Renda e custos

Outros impactos socioeconômicos

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	não conhecido

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:

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

6.5 Adoção da tecnologia

Comentários:

Comments on spontaneous adoption: The SLM Technology is not implemented by local land users but this SLM technology needs to be implemented by spatial planning of the county / federal state.

There is a little trend towards spontaneous adoption of the Technology

Comments on adoption trend: The SLM Technology is not yet implemented by land users but first it needs to be considered in spatial planning of the county and the federal state. Land users and local experts showed during participatory workshops that there may be a chance for implementation.

6.7 Pontos fortes/vantagens/oportunidades da tecnologia

Pontos fortes/vantagens/oportunidades na visão do usuário da terra

Protection of vulnerable landscape by building the retention area in the low elevated parts of the landscape that are up to date already difficult to drain. The retention area will support 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 (including strengthening of the ditch system and in-creasing pumping capacity).

Pontos fortes/vantagens/oportunidades na visão do/a compilador/a ou de outra pessoa capacitada
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. Fresh water in the retention areas prevent saline ground water from up dwelling How can they be sustained / enhanced? Build polders where saline ground water dwells up.
Endangered species might obtain new habitats in the retention area How can they be sustained / enhanced? Cessation of agricultural land use can help to improve the habitats for endangered species and increase attractiveness for tourism.
Through investments in building retention areas the very expensive strengthening of existing drainage structures is not necessary anymore How can they be sustained / enhanced? Alternative benefits for land owner can be generated e.g. increas-ing the attractiveness for tourism.

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?
Retention area in a region of high relevance for tourism. The retention area will change the landscape and this may reduce the value of the region for tourism	Include interests from tourism in the retention area (access, information, attractivity).
Endangered species might lose habitats when establishing 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.

Pontos fracos/vantagens/riscos na visão do/a compilador/a ou de outra pessoa capacitada	Como eles podem ser superados?
Loss of land for agricultural production	Build up retention area in low elevated parts, where the productivity is already poor.
For peat formation wet conditions are necessary, but under wet conditions highest methane emissions were measured. The emissions due to methane are therefore higher than the potential storage effects due to carbon sequestration.	Ground water levels should kept stable near to the soil surface.

7.2 Referências às publicações disponíveis

Título, autor, ano, ISBN:

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

7.3 Links para informação relevante que está disponível online

Título/ descrição:

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