Technologies

Drainage of coastal areas in north- western Germany [Germany]

Tiefliegenden Küstenlandschaften mit künstlicher Entwässerung in Nordwestdeutschland

technologies_1714 - Germany

Completeness: 78%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:

Kleyer Michael

University of Oldenburg

Germany

SLM specialist:

Karrasch Leena

University of Oldenburg

Germany

SLM specialist:

Mayer Martin

University of Oldenburg

Germany

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Book project: Making sense of research for sustainable land management (GLUES)
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Sustainable Coastal Land Management (COMTESS / GLUES)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
University of Oldenburg (University of Oldenburg) - Germany

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Land reclaimed from the sea – ‘the coastal region in north-western Germany needs to be artificially drained, and this will be an increasing challenge with climate change.

2.2 Detailed description of the Technology

Description:

In some coastal locations of north-western Germany, during the 19th and 20th century, land was reclaimed from the sea: at present, the land lies below sea level. It is protected from the sea by a wall called ‘dyke’. The reason for reclamation by drainage and walls was to make use of the fertile soil for intensive cropland or pastures. In the Landkreis Aurich region, agriculture is the most important form of land use: it is the main source of income, supplemented by tourism.

Purpose of the Technology: However, in anticipation of the expected increase in winter precipitation due to climate change, extra freshwater discharge will need to be dealt with. Furthermore, the periods when natural discharge of freshwater into the sea can occur is likely to become shorter, due to the sea level rising – again as a result of climate change. Consequently, in autumn and winter, more freshwater will have to be pumped into the sea rather than being discharged naturally during low tides.

Establishment / maintenance activities and inputs: A dense drainage network enables intensive agriculture on the landward side of the primary sea wall. In total, one third of the Krummhörn community’s land is used for crops and one third as pasture. Drainage water from land which lies below sea level is pumped into the main drainage channels - which are at higher elevations and discharge naturally into the sea during low tides.

Natural / human environment: During storm tides when the sea level is high, large amounts of excess drainage water need to be pumped into the sea instead of naturally discharging. However, with climate change the present drainage network will no longer be capable of discharging all of the excess freshwater as a result of increased precipitation and sea level rise. This will require considerable investments in higher pumping capacities and an adapted drainage system with increased dimensions of ditches, as well as additional ditches in areas with a high flooding risk.

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

Country:

Germany

Region/ State/ Province:

Germany, Lower Saxony

Further specification of location:

Landkreis Aurich

Comments:

Total area covered by the SLM Technology is 33.7 km2.

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • more than 50 years ago (traditional)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • as part of a traditional system (> 50 years)
Comments (type of project, etc.):

Traditional land use with dense drainage network to enable intensive agricultural land use in low elevated coastal landscapes.

3. Classification of the SLM Technology

3.2 Current land use type(s) where the Technology is applied

Land use mixed within the same land unit:

Yes

Specify mixed land use (crops/ grazing/ trees):
  • Agro-pastoralism (incl. integrated crop-livestock)

Cropland

Cropland

  • Annual cropping
Annual cropping - Specify crops:
  • cereals - barley
  • cereals - maize
  • wheat
Number of growing seasons per year:
  • 1
Specify:

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

Grazing land

Grazing land

Intensive grazing/ fodder production:
  • Cut-and-carry/ zero grazing
  • Improved pastures
Animal type:
  • cattle - dairy
  • cattle - non-dairy beef
Products and services:
  • meat
  • milk
Comments:

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.

Livestock density: > 100 LU /km2

3.3 Has land use changed due to the implementation of the Technology?

Has land use changed due to the implementation of the Technology?
  • No (Continue with question 3.4)
Comments:

Mixed: Mp: Agro-pastoralism

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • mixed rainfed-irrigated
Comments:

Water supply: rainfed, mixed rainfed - irrigated

3.5 SLM group to which the Technology belongs

  • water diversion and drainage
  • surface water management (spring, river, lakes, sea)

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S3: Graded ditches, channels, waterways
Comments:

Main measures: structural measures

3.7 Main types of land degradation addressed by the Technology

water degradation

water degradation

  • Hg: change in groundwater/aquifer level
Comments:

Main type of degradation addressed: Hg: change in groundwater / aquifer level

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))

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

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) characterize the region. The traditional dense drainage network sometimes lacks the capacity to drain the lower land. This leads to flooding and limits agricultural productivity. It is expected that this flooding will increase with climate change. Agricultural production is faced with increased risks of crop failure in the future, unless the drainage system is strengthened.

Location: Krummhörn. County of Aurich, Lower Saxony

Technical knowledge required for land users: moderate

Main technical functions: decrease groundwater level by artificial drainage

Construction material (earth): digged in soil, no specific material needed

Author:

Udo Schotten

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

EURO

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

0.94

Indicate average wage cost of hired labour per day:

100.00

4.4 Costs and inputs needed for establishment

Comments:

Duration of establishment phase: 3 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Maintenance of drainage system (ditches) once per year

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Other Maintenance cost pre km ditch km ditch 2270.7

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Cost are affected by soil types and cost of labour. The calculation is based on the mean costs over many years. This gives a mean annual cost of Euro 2,270 per km ditch per year. With 1,145 km of ditches this totals Euro 2,600,000 per year for the whole area (approx. 49,000 ha).

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • humid

Thermal climate class: temperate

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
Landforms:
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • fine/ heavy (clay)
Topsoil organic matter:
  • high (>3%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

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

5.4 Water availability and quality

Ground water table:

< 5 m

Availability of surface water:

good

Water quality (untreated):

for agricultural use only (irrigation)

5.5 Biodiversity

Species diversity:
  • low

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • commercial/ market
Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • average
Individuals or groups:
  • employee (company, government)
Level of mechanization:
  • mechanized/ motorized
Gender:
  • women
  • men
Indicate other relevant characteristics of the land users:

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 15% of the land.

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

5.7 Average area of land used by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • large-scale
Comments:

Average area of land owned or leased by land users applying the Technology: 5-15 ha, 15-50 ha, 50-100 ha, 100-500 ha

5.8 Land ownership, land use rights, and water use rights

Land ownership:
  • individual, not titled
Land use rights:
  • individual

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

crop production

decreased
increased

fodder production

decreased
increased

fodder quality

decreased
increased

risk of production failure

increased
decreased

production area

decreased
increased
Water availability and quality

drinking water availability

decreased
increased

irrigation water availability

decreased
increased
Income and costs

farm income

decreased
increased

Socio-cultural impacts

recreational opportunities

reduced
improved

Ecological impacts

Water cycle/ runoff

water quantity

decreased
increased

water quality

decreased
increased

surface runoff

increased
decreased

groundwater table/ aquifer

lowered
recharge
Soil

salinity

increased
decreased

soil organic matter/ below ground C

decreased
increased
Biodiversity: vegetation, animals

plant diversity

decreased
increased
Comments/ specify:

Reduced crop diversity

habitat diversity

decreased
increased
Comments/ specify:

Increased habitat fragmentation

6.2 Off-site impacts the Technology has shown

downstream flooding

increased
reduced

damage on neighbours' fields

increased
reduced

damage on public/ private infrastructure

increased
reduced

Excess water

decreased
Increased

Hazard towards adverse events

Decreased
Increased

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change
Season increase or decrease How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm not well
local windstorm not well
Climatological disasters
How does the Technology cope with it?
drought well
Hydrological disasters
How does the Technology cope with it?
general (river) flood not well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period not known
climate change not well

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

very negative

Long-term returns:

positive

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

positive

Long-term returns:

very positive

Comments:

Development of dense drainage network is very cost intensive but last for very long time. Maintainance cost are quite low compared to the benefits of intensive land use.

6.5 Adoption of the Technology

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 91-100%
Comments:

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

Comments on spontaneous adoption: Well established technology in the whole region.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Optimal for agricultural production

How can they be sustained / enhanced? Invest in infrastructure to maintain the system
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
High agricultural production

How can they be sustained / enhanced? Strengthen the drainage system to adapt to climate change

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
High drainage costs Development of water retention areas ( see A_GER001_en, A_GER002_en and A_GER003_en)
Landscape vulnerable to climate change Development of water retention areas (see A_GER001_en, A_GER002_en and A_GER003_en)

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

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

7.3 Links to relevant online information

Title/ description:

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

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