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)?

10/06/2015

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 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 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. 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 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 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

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: 240Longest 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. 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 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	10000000,0	10000000,0
Equipamento	Machine use	Dam	1,0	4000000,0	4000000,0
Material de construção	Earth	Dam	1,0	112000,0	112000,0
Custos totais para a implantação da tecnologia					14112000,0

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.	Maintenance of drainage system	Estrutural	once a year (mean of many years)

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	500,0	500,0
Equipamento	Machine use	Dam	1,0	200,0	200,0
Material de construção	Earth	Dam	1,0	100,0	100,0
Outros	Maintenance per km ditch	Dam	1,0	2270,7	2270,7
Custos totais para a manutenção da tecnologia					3070,7

Comentários:

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 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 (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 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 fertility is high
Soil drainage/infiltration is meidum
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.
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 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 an 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 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 Pontos fortes/vantagens/oportunidades da tecnologia

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

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 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 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 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

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	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 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/