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

有助于对技术进行记录/评估的项目名称（如相关）

Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )

有助于对技术进行记录/评估的机构名称（如相关）

Wageningen Environmental Research (Alterra) - 荷兰

有助于对技术进行记录/评估的机构名称（如相关）

Provincie Holland Zuid - 荷兰

有助于对技术进行记录/评估的机构名称（如相关）

Provincie Utrecht - 荷兰

有助于对技术进行记录/评估的机构名称（如相关）

LTO NOORD - 荷兰

有助于对技术进行记录/评估的机构名称（如相关）

Waterschap Amstel, Gooi en Vecht - 荷兰

1.3 关于使用通过WOCAT记录的数据的条件

（现场）数据是什么时候汇编的？:

30/10/2015

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。:

是

2.1 技术简介

技术定义:

Submerged drains are drains installed in grassland on peatsoils with the aims to decrease soil subsidence and emission of CO2 and N2O due to the oxidation of peat soil, and to maintain suitable groundwater levels in fields for grassland production and grazing.

2.2 技术的详细说明

说明:

Contrary to usual drains, submerged drains are installed below ditchwater level. Submerged drains diminish the differences between ditch level and groundwater level in the fields by enabling the infiltration from ditch to field and the drainage from field to ditch.
In summer and dry periods the infiltration from ditch to field is much lower than the evapotranspiration of the grass, resulting in a lowering of the groundwater level some decimetres below ditch water level. With submerged drains the groundwater level is lowered less drastically because infiltration from ditch to field is improved. In winter and wet periods, fields are drained
more quickly compared to conventional drainage.

Purpose of the Technology: Submerged drains diminish the differences between ditch level and groundwater level in the fields by enabling the infiltration from ditch to field and the drainage from field to ditch. Under peak rainfall events groundwater levels become less high and remain at high levels for shorter times than in fields without submerged drains.
Due to the increased groundwater level in summer the decomposition of the peat soil is reduced. As a result, the rate of soil subsidence is decreased and also the emission of greenhouse gases and of N and P released to the surface water.

Establishment / maintenance activities and inputs: The installation of submerged drains is done with common drainage installation machines. Submerged drains should be installed between 15 and 25 cm below the ditch water level, and between 45 and 75 cm below the soil surface. The drain pipes should have a diameter of at least 6 cm. The distance between drains is at most 6 m. Drain length is at most 300 m. Submerged drains can be installed in the length or width direction of a field. Drains must be installed level.

Natural / human environment: Submerged drains were designed for peat soils under permanent pasture for dairy farming. More than 70 % of Dutch peat soils are under this land use. Drainage of these peat soils results in subsidence, mainly by decomposition (oxidation) of the peat (partly by shrinkage and consolidation). This is an ongoing process, because every 10 to 15 year ditchwater levels are adapted to the lowered surface in order to enable dairy farming and to prevent the conversion to wetlands. Soil subsidence causes several problems: decreased suitability for grazing and grassland farming, increased flood risk, emission of greenhouse gases, damage to infrastructure (dikes, roads, foundations, sewerage networks) and increased cost of water management.

Submerged drains were tested with a network of practitioners and 10 dairy farmers in the Dutch peat soil area between 2011 and 2013 on an area of 20 ha.

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

2.6 实施日期

如果不知道确切的年份，请说明大概的日期:

• 不到10年前（最近）

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

• stimulated by regional authorities

注释（项目类型等）:

Since 2003 submerged drains have been applied on several experimental farms in The Netherlands. Implementations over larger areas (i.e. a water management unit, 'peilval' in Dutch) will be done in 2016.

2007: research on soil subsidence in the Western peat area following the large scale groundweter level lowering in the 1960s and 1970s signalled the high rate of soil subsidence (5-12 mm/y) (Van den Akker et al., 2007a)

2008: concerns about soil subsidence in the western peat area from the provincial autorities of Noord-Holland, Utrecht and Zuid-Holland in the policy document 'Voorloper Groene Hart' (2008)

2008-2012: various research projects to test the effectiveness of submerged drains to reduce soil subsidence and to improve conditions for dairy farming, and on the effects for water quality: www.waarheenmethetveen.nl, Hoving et al. (2008), Woestenburg (2009), EU project EUROPEAT, Woestenburg et al. 2009; Jansen et al., 2010; Hendriks and Van den Akker, 2012; Hoving et al. (2008, 2009, 2013)

2011-2012: research on the Peat Area Innovation Centre (VIC) to test effects of submerged drainage in combination with dynamic groundwater level management (Hoving et al., 2013)

2012- testing by research instsiutes of economic viability of submerged drains with regard to water level management and agricultural productivity, on assignment of the province Noord-Holland, waterboard Hollands Noorderkwartier.

2009-2011: various modelling studies assigned by the provinces and water boards of the western peat meadow area on the effects of submerged drains for the demand for inlet and discharge of water and effects on the decomposition of peat and the water quality.

2011: model research on effects of submerged drains on the water demand of the western peat area until 2050 under climate change (Van den Akker et al., 2011)

2010-2013 experimental research in 3 pilots initiated by the province of Utrecht and Zuid-Holland, four water boards and the farmers' organisation LTO Noord. Aim: to test if the application of submerged drains results in larger amounts of water to supply and to discharge from the peat meadow area, and to test if the submerged drains result in a larger load of nutrients to ditches,

3.2 应用该技术的当前土地利用类型

注释:

Major land use problems (compiler’s opinion): The major land use problems in the Western Dutch peat soil area is soil subsidence due to the lowering of the groundwater level in the 1960s and 1970s. The soil subsidence amounts to 0-2.5 cm per year. It is mainly caused by the oxidation of peat soil, which releases nutrients to soil and surface water, and CO2 and N2O to the atmosphere. The soil subsidence causes several problems:
- damage to buildings and infrastructure
- increasing costs of water management: high groundwater levels require pumping of water to enable agricultural use, and storage of rainfall excess water during peak rainfall events
- drainage of nature reserves to lowered agricultural land
- water pollution: the lowering of the groundwater level causes upward seepage of nutrient-rich water to polders
- greenhouse gas emissions (2-3% of total CO2 emissions in The Netherlands)
- loss of peat soils (2% per year in the NL)
- increased flood risk (due to combination with sealevel rise)

Major land use problems (land users’ perception): Grassland and arable farming are hampered by high groundwater levels due to a lowered bearing capacity and too wet conditions for crops. Maintaining the groundwater level at a level high enough to prevent the decomposition of peat soil would imply a conversion to wetlands and forest swamps. This is not acceptable to various kinds of land users (nature managers, farmers, users of built-up area). This would also mean the loss of the cultural historic open landscape and habitat for meadow birds, strongly reduced economic possibilities and an increased demand of water from the rivers (view of water managers and governments).

Future (final) land use (after implementation of SLM Technology): Grazing land: Gi: Intensive grazing/ fodder production

如果由于技术的实施而导致土地用途发生变化，则在技术实施前说明土地利的用途。:

Grazing land: Gi: Intensive grazing/ fodder production

3.3 有关土地利用的更多信息

该技术所应用土地的供水:

• 雨养

具体说明:

Longest growing period in days: 270Longest growing period from month to month: April-October

牲畜密度（如相关）:

> 100 LU /km2

3.4 该技术所属的SLM组

• 引水和排水
• 地下水管理

3.5 技术传播

注释:

Total area covered by the SLM Technology is 0.054 m2.

The measure was tested in three pilots in the areas Krimpenerwaard, Keulevaart and Demmerkiksekade. Each pilot covered two fields: one with submerged drains and one without. The area given refers to the pilot in the Krimpenerwaard.

3.6 包含该技术的可持续土地管理措施

注释:

Main measures: management measures

Specification of other management measures: maintaining high groundwater level

3.7 该技术强调的主要土地退化类型

注释:

Main type of degradation addressed: Cn: fertility decline and reduced organic matter content, Ps: subsidence of organic soils, settling of soil

Secondary types of degradation addressed: Pw: waterlogging, Hg: change in groundwater / aquifer level, Hp: decline of surface water quality

Main causes of degradation: other human induced causes (specify) (lowering of the groundwater level to enable agricultural use of the peat soils results in soil subsidence and detioration of ground- and surface water quality due to capillary rise)

Secondary causes of degradation: change in temperature (higher temperatures under climate change increase the decomposition rate of peat soil; subsidence and CO2 emissions will increase by 75%), change of seasonal rainfall (decrease in summer rainfall (23% in warm and dry CC scenario for NL)), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (maintenance of high water levels in built-up and natural areas increases the difference in groundwater level with agricultural land onb peat soils)

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:

• 减少土地退化

4.1 该技术的技术图纸

4.2 技术规范/技术图纸说明

The picture shows a cross section through an agricultural field, bounded by two ditches. A submerged drain (yellow bar in the picture) is installed at 80 cm below the soil surface. It ends in the ditch on the left side at 20 cm below the water level in the ditch. The dotted line indicates the position of the groundwater table in the situation without the submerged drain; the continuous blue line indicates the position in the situation where the submerged drain is installed. The lines show that in summer the groundwater level is raised to nearly the level of the ditch water by the submerged drain, whereas the level would be approximately 30 cm lower without the drain.
In winter, in the situation with the submerged drain, the groundwater level is around 40 cm below the soil surface. This enables the farmer to use the field for grazing or to traffic the field. However, in the situation without the drain, the groundwater level nearly reaches the soil surface in the centre of the field, impeding traffic or grazing on the field.

Technical knowledge required for field staff / advisors: moderate (Estimates of economic benefits due to increased grass production and grazing periods vary between years with meteorological conditions.)

Technical knowledge required for land users: moderate (Specific conditions apply to the dimensions and positioning of submerged drains in the fields. Level position and lebgth are critical.)

Technical knowledge required for companies installing the drains: moderate (Specific conditions apply to the dimensions and positioning of submerged drains in the fields. Level position and lebgth are critical. Soil must have sufficient bearing capacity during installation.)

Technical knowledge required for water board: moderate (submerged drains increase the water supply and discharge from groundwater level management units. Additional pumping effort can be prevented by informed water level management.)

Technical knowledge required for researchers: (the implications of submerged drains on the water management in an entire management unit should be explored using coupled hydraulic and rainfall-runoff models.)

Main technical functions: improvement of topsoil structure (compaction), maintaining soil organic matter

Secondary technical functions: increase of infiltration, increase / maintain water stored in soil, drainage of excess rainfall

Other type of management: Maintaining high groundwater levels.

4.3 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

注明美元与当地货币的汇率(如相关):1美元=:

1.09

4.4 技术建立活动

	活动	措施类型	时间
1.	maintenance of drains and outlet in ditch	结构性的
2.	installation of submerged drains	管理	in dry periods

4.5 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	maintenance of drains and outlet in ditch	ha	1.0	30.14	30.14	100.0
劳动力	installation of submerged drains	ha	1.0	1980.0	1980.0	100.0
技术建立所需总成本					2010.14

注释:

Lifespan of the drains: 30 years

4.6 维护/经常性活动

	活动	措施类型	时间/频率
1.	maintenance of submerged drains	管理	several times in lifetime of drains (30 y)

4.7 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%
其它	Annual cost incl maintenance	ha	1.0	127.0	127.0	100.0
技术维护所需总成本					127.0

注释:

Machinery/ tools: establishment and installation require specific skills and machinery; hired, not done by the farmer himself

Investment costs of 1500-1800 €/ha are based on submerged drains at 6 m distance. Costs per m of drain establishment based on drains of 6 cm diameter. Costs based on practical experience from farmers. Drains may have a lifetime of 30 years and require little maintenance.

Specific skills and machinery are required for installation and maintenance, hired from a drainage company. The farmer must only ensure that the outlets of the drains in the ditches remain open and undamaged.

4.8 影响成本的最重要因素

描述影响成本的最决定性因素:

We do not have information on specific cost items, only on establishment costs ad between 1500 and 1800 euro/ha, and annual cost of 117 €/ha incl maintenance, assuming a 20-year life time. Establishment costs can also be expressed per m of drain, i.e. 1.10 EURO per m including materials (drain of 6 cm diameter).

Determinate factors include size and geometry of fields; installation in the length direction is cheaper, and results in fewer outlets in the receiving ditch.

5.1 气候

5.2 地形

关于地形的注释和进一步规范:

Altitudinal zone: 0-100 m a.s.l. (Submerged drains are designed for polders in lowland areas on peat soils)
Landforms: Plateau/plains (submerged drains are designed to drain level fields)
Slopes on average: Flat (submerged drains are designed to drain flat terrain, based on hydraulic prressure head differences between field and ditch)

5.3 土壤

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 depth on average: Very deep (if the peat substrate is considered as part of the soil profile, soils are deeper than 120 cm, with peat packages up to 13 m in some parts of the western Dutch peatland area) and shallow (If the top of the C-horizon is considered as the bottom of the soil profile. C-horizons typically start at 15-30 cm below the soil surface)
Soil texture is fine/heavy (for peat soils with a clayey top layer. In peat soils without such a top layer, a soil texture indication is not applicable. Peat soils are defined as having at least 40 cm of peat in the top 80 cm)
Soil fertility is very high (peat soils are able to supply ample nutrients to plants provided that they are well drained)
Topsoil organic matter is high (Organic matter contents in the topsoil are above 20%. Peat soils are defined as having at least 40 cm of peat in the top 80 cm according to the Dutch soil classification system)
Soil drainage/infiltration is poor/none (peat soils inherently have poor drainage due to their low position with reference to the groundwater level in the regional water system. Values of Ksat reported 2.9-5.0 cm/d)
Soil water storage capacity is very high (the soil water storage capacity is very high due to the large pore space (0.70-0.90 m3/m3))

5.4 水资源可用性和质量

关于水质和水量的注释和进一步规范:

Ground water table: <5m (Average lowest grondwater level in the pilot region is 5-10 cm below the soil surface; average highest level 55-65 cm)
Availability of surface water is good (surface water is amply available due to the low position of the peat soil area compared to the mean sea level, and due to the dense network of ditches and other surface water conveyors and bodies) and excess (surface water levels are under continuous control by the water boards. Therefore flood situations do not occur, but under high-intensity rainfall events fields may submerge)
Water quality (untreated) is for agriculutral use only (Irrigation, surface and groundwater can be used for agriculture without treatment. Nutrient rich water emerging by capillary rise in polders may not be suitable for nature.)
Biodiversity is medium (the grasslands in the western peatsoil area are suitable habtitats for meadow birds)

5.5 生物多样性

5.6 应用该技术的土地使用者的特征

说明土地使用者的其他有关特征:

Difference in the involvement of women and men: Executives of agricultural enterprises in The Netherlands are usually men.
Population density: 200-500 persons/km2
Annual population growth: 1% - 2%
100% of the land users are average wealthy and own 100% of the land.
Off-farm income specification: Dairy farmers in this part of The Netherlands spend 100% of their time on the farm. Sometimes their wives have jobs earning off-farm income.
Market orientation is commercial/market (intensive dairy farming in the NL produces for the market)

5.7 应用该技术的土地使用者拥有或租用的平均土地面积

5.8 土地所有权、土地使用权和水使用权

土地所有权:

• 个人，有命名

土地使用权:

• 个人

用水权:

• 租赁

5.9 进入服务和基础设施的通道

6.1 该技术的现场影响

社会经济效应

生产

收入和成本

其它社会经济效应

社会文化影响

生态影响

水循环/径流

土壤

生物多样性:植被、动物

减少气候和灾害风险

其它生态影响

6.2 该技术的场外影响已经显现

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	气候变化/极端天气的类型	该技术是如何应对的？
年温度		增加	好

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	好
局地风暴	好

气候灾害

	该技术是如何应对的？
干旱	未知

水文灾害

	该技术是如何应对的？
比较和缓的（河道）洪水	好

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	好

注释:

Under extreme rainfall events, submerged drains cannot prevent that the groundwater level rises to above the soil surface. However, the groundwater level will fall more quickly with submerged drainas than without, on average to 10 cm lower levels.

Effects of dry summers have not yet been measured in experiments.

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）？

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）？

注释:

A longer grazing season and the extra yield of fodder are the basis for a viable implementation of submerged drainage for land users. The CBA considers establishment and maintenance costs together: establishment costs of € 1800,-/ha, discounted over 20 years, including maintenance, result in annual cost of € 117,-/ha (6.5% of the investment). Benefits include 500 kg DM/ha extra grass use and 30 extra grazing days. This would yield € 171/ha, resulting in a net saldo of € 54,-. In addition SMD are an investment in sustainable soil management, resulting in an increased economic value of the land in the long term.

6.5 技术采用

如若可行，进行量化（住户数量和/或覆盖面积）:

13

在所有采用这项技术的人当中，有多少人是自发地采用该技术，即未获得任何物质奖励/付款？:

• 90-100%

注释:

13 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: The area under submerged drainage implemented by the 10 dairy farmers from the Community of Practice is 20 ha. The area under SMD in the three pilots described in this questionnaire is roughly an additional 0.05 km2 per farm.

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: Due to the growing interest in the peat soil area because of the relevance for climate mitigation and the economic risks of soil subsidence there is growing interest in SMD in combination iwth dynamic groundwater level management to reduce the rate of soil subsidence. Subsidy arrangements are in preparation, which will stimulate adoption of the technology by more dairy farmers.

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
Submerged drains increase the number of days with a good bearing capacity of grassland, and therefore enable a longer grazing season and less trampling of grass.
Higher effective yield in total.
Short term: slightly cost effective. Long term: good cost effective.

编制者或其他关键资源人员认为的长处/优势/机会
Submerged drains allow a strong reduction of soil subsidence and GHG emissions (at least 50%, even >50% if combined with higher ditch water levels). How can they be sustained / enhanced? Further implementation by dairy farmers in the peat-meadow area. For this purpose the Community of Practice is recommended, as well as the arrangement of subsidies and the active involvement of regional government and water board. This applies to all mentioned advantages.
The quality of surface water in ditches will slightly improve.
Less problems with difference between subsiding soil surfaces and constant water levels in lakes and high water ditches (along houses).
Less sub-polders with a certain fixed ditch water level, and possibility to create areas with a high surface level (with submerged drains) and a low surface level (without SD).

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？
Grass yield is lower due to reduced mineralization of nitrogen.	Yield could be increased due to better usage of manure (better NUE). On the other hand yield is increased due to increased number of days with a good bearing capacity of grassland, and a longer grazing season and less trampling of grass.

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？
Submerged drains require more inlet water to polders.	Reduction of inlet requirement is possible by smart water management. This implies water level margins of +/- 10 cm and the use of weather forecasting.
Submerged drains require a bit more pumping to drain water under extreme rain events.

7.2 参考可用出版物

标题、作者、年份、ISBN:

Several reports on submerged drainage are available from Alterra, Wageningen UR (in Dutch). The report used for this WOCAT QT is:Effecten van onderwaterdrains in peilvak 9 van polder Groot-Wilnis Vinkeveen : modelstudie naar de effecten van onderwaterdrains op maaivelddaling, waterbeheer, wateroverlast en waterkwaliteit in peilvak 9 Author(s)Hendriks, R.F.A.; Akker, J.J.H. van den; Jansen, P.C.; Massop, H.Th.L. SourceWageningen : Alterra Wageningen UR, 2014 (Alterra-rapport 2480) - p. 124Other literature (in Dutch): Waarheen met het veen. Woestenberg, M. 2009. Uitegeverij Landwerk and Alterra, Wageningen URhttp://www.levenmetwater.nl/static/media/files/Boek_wmhv_def.pdf

可以从哪里获得?成本如何?

Alterra Reports are available atlibrary.wur.nl