技术

Water retention polders without agriculture to improve water management [德国]

Ungenutzter Polder zur Verbesserung des Wassermanagements (Nordsee Region)

technologies_1582 - 德国

完整性: 82%

1. 一般信息

1.2 参与该技术评估和文件编制的资源人员和机构的联系方式

关键资源人

SLM专业人员:

Kleyer Michael

University of Oldenburg

德国

SLM专业人员:

Karrasch Leena

University of Oldenburg

德国

SLM专业人员:

Mayer Martin

University of Oldenburg

有助于对技术进行记录/评估的项目名称(如相关)
Book project: Making sense of research for sustainable land management (GLUES)
有助于对技术进行记录/评估的项目名称(如相关)
Sustainable Coastal Land Management (COMTESS / GLUES)
有助于对技术进行记录/评估的机构名称(如相关)
University of Oldenburg (University of Oldenburg) - 德国

1.3 关于使用通过WOCAT记录的数据的条件

编制者和关键资源人员接受有关使用通过WOCAT记录数据的条件。:

1.5 参考关于SLM方法(使用WOCAT记录的SLM方法)的调查问卷

2. SLM技术的说明

2.1 技术简介

技术定义:

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 技术的详细说明

说明:

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 技术照片

2.5 已应用该技术的、本评估所涵盖的国家/地区/地点

国家:

德国

区域/州/省:

Germany, Lower Saxony

有关地点的进一步说明:

Landkreis Aurich

具体说明该技术的分布:
  • 均匀地分布在一个区域
如果技术均匀分布在一个区域,则指定覆盖的区域(单位为平方千米):

33.7

注释:

Total area covered by the SLM Technology is 33.7 km2.

2.6 实施日期

如果不知道确切的年份,请说明大概的日期:
  • 10-50年前

2.7 技术介绍

详细说明该技术是如何引入的:
  • 在实验/研究期间
  • 通过项目/外部干预

3. SLM技术的分类

3.2 应用该技术的当前土地利用类型

同一土地单元内混合使用的土地::

具体说明混合土地使用(作物/放牧/树木):
  • 农牧业(包括农牧结合)

农田

农田

  • 一年一作
年作 - 具体指明作物:
  • 谷类 - 大麦
  • 谷物类 - 玉米
  • wheat
每年的生长季节数:
  • 1
具体说明:

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

牧场

牧场

集约放牧/饲料生产:
  • 收割和携带/零放牧
  • 改良牧场
动物类型:
  • 牛 - 奶制品
  • 牛 - 非奶牛牛肉
产品和服务:
  • 肉类
  • 奶类
注释:

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

Livestock density : > 100 LU /km2

3.4 供水

注释:

Water supply: rainfed, mixed rainfed - irrigated

3.5 该技术所属的SLM组

  • 地表水管理(泉、河、湖、海)
  • 湿地保护/管理
  • Flood prevention

3.6 包含该技术的可持续土地管理措施

结构措施

结构措施

  • S5:大坝、集水斗、水池
管理措施

管理措施

  • M1:改变土地使用类型
  • M2:改变管理/强度级别
注释:

Main measures: structural measures

Secondary measures: management measures

3.7 该技术强调的主要土地退化类型

化学性土壤退化

化学性土壤退化

  • Cs:盐化/碱化
水质恶化

水质恶化

  • Hs:地表水良变化
  • Hg:地下水/含水层水位的变化
  • Hq:地下水水质下降
注释:

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 防止、减少或恢复土地退化

具体数量名该技术与土地退化有关的目标:
  • 防止土地退化
  • 减少土地退化
注释:

Main goals: prevention of land degradation

Secondary goals: mitigation / reduction of land degradation

4. 技术规范、实施活动、投入和成本

4.1 该技术的技术图纸

技术规范(与技术图纸相关):

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

作者:

Udo Schotten

4.2 有关投入和成本计算的一般信息

其它/国家货币(具体说明):

Euro

如相关,注明美元与当地货币的汇率(例如1美元=79.9巴西雷亚尔):1美元=:

0.94

注明雇用劳工的每日平均工资成本:

100.00

4.3 技术建立活动

活动 时间(季度)
1. Building of dams during winter months

4.4 技术建立所需要的费用和投入

对投入进行具体说明 单位 数量 单位成本 每项投入的总成本 土地使用者承担的成本%
劳动力 Labour Dam 1.0 21000000.0 21000000.0
设备 Machine use Dam 1.0 9000000.0 9000000.0
施工材料 Earth Dam 1.0 750000.0 750000.0
技术建立所需总成本 30750000.0
技术建立总成本,美元 32712765.96
注释:

Duration of establishment phase: 3 month(s)

4.5 维护/经常性活动

活动 时间/频率
1. Control of dams once a year
2. Maintenance of dams once a year
3. Maintanance of drainage system once a year

4.6 维护/经常性活动所需要的费用和投入(每年)

对投入进行具体说明 单位 数量 单位成本 每项投入的总成本 土地使用者承担的成本%
劳动力 Labour Dam 1.0 800.0 800.0
设备 Machine use Dam 1.0 300.0 300.0
施工材料 Earth Dam 1.0 100.0 100.0 1.0
其它 Maintenance per km ditch Dam 1.0 2270.7 2270.7
技术维护所需总成本 3470.7
技术维护总成本,美元 3692.23
注释:

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.

4.7 影响成本的最重要因素

描述影响成本的最决定性因素:

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. 自然和人文环境

5.1 气候

年降雨量
  • < 250毫米
  • 251-500毫米
  • 501-750毫米
  • 751-1,000毫米
  • 1,001-1,500毫米
  • 1,501-2,000毫米
  • 2,001-3,000毫米
  • 3,001-4,000毫米
  • > 4,000毫米
农业气候带
  • 潮湿的

Thermal climate class: temperate

5.2 地形

平均坡度:
  • 水平(0-2%)
  • 缓降(3-5%)
  • 平缓(6-10%)
  • 滚坡(11-15%)
  • 崎岖(16-30%)
  • 陡峭(31-60%)
  • 非常陡峭(>60%)
地形:
  • 高原/平原
  • 山脊
  • 山坡
  • 山地斜坡
  • 麓坡
  • 谷底
垂直分布带:
  • 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 土壤

平均土层深度:
  • 非常浅(0-20厘米)
  • 浅(21-50厘米)
  • 中等深度(51-80厘米)
  • 深(81-120厘米)
  • 非常深(> 120厘米)
土壤质地(表土):
  • 细粒/重质(粘土)
表土有机质:
  • 高(>3%)
如有可能,附上完整的土壤描述或具体说明可用的信息,例如土壤类型、土壤酸碱度、阳离子交换能力、氮、盐度等。:

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

5.4 水资源可用性和质量

地下水位表:

< 5米

地表水的可用性:

水质(未处理):

仅供农业使用(灌溉)

5.5 生物多样性

物种多样性:

5.6 应用该技术的土地使用者的特征

生产系统的市场定位:
  • 商业/市场
非农收入:
  • 收入的10-50%
相对财富水平:
  • 平均水平
个人或集体:
  • 员工(公司、政府)
机械化水平:
  • 机械化/电动
性别:
  • 女人
  • 男人
说明土地使用者的其他有关特征:

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 应用该技术的土地使用者使用的平均土地面积

  • < 0.5 公顷
  • 0.5-1 公顷
  • 1-2 公顷
  • 2-5公顷
  • 5-15公顷
  • 15-50公顷
  • 50-100公顷
  • 100-500公顷
  • 500-1,000公顷
  • 1,000-10,000公顷
  • > 10,000公顷
这被认为是小规模、中规模还是大规模的(参照当地实际情况)?:
  • 大规模的
注释:

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

5.8 土地所有权、土地使用权和水使用权

土地所有权:
  • 个人,未命名
土地使用权:
  • 个人

5.9 进入服务和基础设施的通道

健康:
  • 贫瘠
  • 适度的
教育:
  • 贫瘠
  • 适度的
技术援助:
  • 贫瘠
  • 适度的
就业(例如非农):
  • 贫瘠
  • 适度的
市场:
  • 贫瘠
  • 适度的
能源:
  • 贫瘠
  • 适度的
道路和交通:
  • 贫瘠
  • 适度的
饮用水和卫生设施:
  • 贫瘠
  • 适度的
金融服务:
  • 贫瘠
  • 适度的

6. 影响和结论性说明

6.1 该技术的现场影响

社会经济效应

生产

作物生产

降低
增加
注释/具体说明:

No agricultural land use in the retention area any more.

饲料生产

降低
增加
注释/具体说明:

No agricultural land use in the retention area any more.

收入和成本

农业收入

降低
增加
其它社会经济效应

Intrusion by saline groundwater

decreased
increased

社会文化影响

娱乐机会

减少
改良
注释/具体说明:

Diversification of landscape by building the retention area will increase the attractivity for recreation and tourists.

SLM/土地退化知识

减少
改良
注释/具体说明:

No agricultural land use under wet conditions results in more diversity and conservation of regional species and habitats.

Improved livelihoods and human well-being

注释/具体说明:

'Regional belonging' and 'feeling of safety' are measured. The amount of increase is modelled and will be added here.

生态影响

水循环/径流

水量

降低
增加
注释/具体说明:

Typical for the region are wet situations. These typical wet conditions are restored by cessation of drainage system within the retention area.

水质

降低
增加
注释/具体说明:

Updwelling of saline groundwater is prevented by increased water level in the retention area.

地下水位/含水层

下降
补水
注释/具体说明:

By water in the retention are the recharge of groundwater will increase and prevents salinization.

蒸发

增加
降低
注释/具体说明:

Instead of pumping water into the sea a higher amount is evapotranspirated naturally.

土壤

土壤水分

降低
增加
注释/具体说明:

Typical for the region are wet situations. These typical wet conditions are restored by cessation of drainage system within the retention area.

盐度

增加
降低
注释/具体说明:

By water in the retention are the recharge of groundwater will increase and prevent salinization.

土壤有机物/地下C

降低
增加
注释/具体说明:

By wetter conditions and due to cessation of land use, the soil organic matter will be increased and peat layers will established..

生物多样性:植被、动物

生物量/地上C

降低
增加

植物多样性

降低
增加
注释/具体说明:

By wet conditions without land use the number of typical local species will be increased.

动物多样性

降低
增加
注释/具体说明:

By wet conditions without land use the number of typical local species will be increased.

有益物种

降低
增加

栖息地多样性

降低
增加
注释/具体说明:

By wet conditions without land use the number of typical local habitats will be increased.

减少气候和灾害风险

碳和温室气体的排放

增加
降低
注释/具体说明:

Modelled is the global warming potential by gas emissions. Not yet clear if it is benefit or disadvantage. Model will show.

6.2 该技术的场外影响已经显现

水资源可用性

降低
增加

旱季稳定可靠的水流

减少
增加
注释/具体说明:

Water stored in retention area can be used for irrigation during dry summer months.

下游洪水

增加
减少
注释/具体说明:

Measured m3 of excess water in the catchment area, leading to floods or needs to be pumped. Exact values from modelling will be added as soon as possible!

对邻近农田的破坏

增加
减少

对公共/私人基础设施的破坏

增加
减少

Production area

SLM之前的数量:

49.000

SLM之后的数量:

48.400

注释/具体说明:

For the whole catchment area a loss of approx. 600 ha (size of retention area).

6.3 技术对渐变气候以及与气候相关的极端情况/灾害的暴露和敏感性(土地使用者认为的极端情况/灾害)

渐变气候

渐变气候
季节 增加或减少 该技术是如何应对的?
年温度 增加

气候有关的极端情况(灾害)

气象灾害
该技术是如何应对的?
局地暴雨
局地风暴
气候灾害
该技术是如何应对的?
干旱
水文灾害
该技术是如何应对的?
比较和缓的(河道)洪水

其他气候相关的后果

其他气候相关的后果
该技术是如何应对的?
缩短生长期 未知

6.4 成本效益分析

技术收益与技术建立成本相比如何(从土地使用者的角度看)?
短期回报:

非常消极

长期回报:

中性/平衡

技术收益与技术维护成本/经常性成本相比如何(从土地使用者的角度看)?
短期回报:

中性/平衡

长期回报:

积极

注释:

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 技术采用

注释:

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 该技术的优点/长处/机会

土地使用者眼中的长处/优势/机会
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).
编制者或其他关键资源人员认为的长处/优势/机会
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 技术的弱点/缺点/风险及其克服方法

土地使用者认为的弱点/缺点/风险 如何克服它们?
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.
编制者或其他关键资源人员认为的弱点/缺点/风险 如何克服它们?
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. 参考和链接

7.1 信息的方法/来源

7.2 参考可用出版物

标题、作者、年份、ISBN:

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

7.3 链接到网络上的相关信息

标题/说明:

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

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