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Leveraging Vinyl Sheet Piles for Peatland Restoration
The extraordinary ability of peatlands to store carbon makes them a key component of natural ecosystems with a significant impact on the global carbon balance. Unfortunately, climate changes and human activity are increasingly leading to the degradation of these valuable areas, contributing to the increase in emissions of carbon dioxide (CO2) and methane (CH4), two major greenhouse gases.
Peatlands have a tremendous ability to cool the climate. Such wetland ecosystems remove carbon from the carbon cycle by binding and storing it underground. In the course of millenia, under the influence of temperature and pressure, it transforms into brown coal, and then into hard coal. For this reason, peatlands are increasingly appearing in the debate on climate change, as they play a fundamental role as carbon reservoirs, effectively reducing greenhouse gas emissions.
European specialists, recognizing the need to protect valuable wetland ecosystems, are looking for innovative solutions to stop the ongoing degradation. This article discusses the use of modern technologies, such as the use of vinyl fences with a seal in projects aimed at protecting peatlands from drying out. Such innovative methods, although less traditional than historically used natural materials, such as wood, offer many environmental, economic, and practical benefits.
Peatland degradation: who is to blame and who will pay the price
Peatlands, one of the largest natural carbon reservoirs, play a key role in the carbon cycle. Climate change and human activity contribute to their degradation, which leads to the release of carbon dioxide (CO2) and methane (CH4) into the atmosphere. In Europe, it is particularly important to consider the local climatic and ecosystem conditions in the analysis of this phenomenon. The drying of peatlands in Europe is a complex phenomenon that has a significant impact on the global environment.
A self-perpetuating cycle of degradation
Human activity has a significant impact on the balance of wetland ecosystems. Intensification of agriculture, uncontrolled urbanization, excessive use of water resources, and large-scale industrial production of peat contribute to the lowering of the groundwater level of peatlands, which leads to their drying out. The drainage initiates the oxidation reaction of carbon stored in peatlands, which is released into the atmosphere in the form of carbon dioxide and methane on a massive scale.
As in a vicious circle, the emission of carbon dioxide and methane contributes to the progression of climate change which triggers further global warming, which in turn intensifies the process of peatlands drainage. Greenhouse gases emitted by peatlands further enhance the greenhouse effect, closing the cycle and exacerbating the problem.
A precious repository
Peatlands are home to many unique species of plants and animals that have adapted to living in specific, humid conditions. Drainage of wetland ecosystems leads not only to the degradation of these delicate habitats, but also to the loss of biodiversity. Plant and animal species that disappear due to the drying out of peatlands are often irrevocably lost to the natural world, which is a significant blow to the ecological balance.
In addition, peatlands play a key role in the regulation of the water cycle. Their ability to store water and release it gradually helps to maintain hydrologic stability in the regions in which they are located. That is why, the drying out of peatlands can lead to grave changes in local water systems, affecting the availability of water for both people and agriculture. The loss of this water regulation capacity of peatlands can have far-reaching consequences for local ecosystems and economies.
Studies of European peatlands have identified several key findings relevant to local conditions.
In Europe, plant diversity declines after peatland drainage, particularly affecting the recolonization of mosses, including Sphagnum [1]. Rewetting peatlands leads to graminoid vegetation establishment, which in most areas hinders the original biodiversity and ecosystem functioning for several decades.
The studies which were carried out indicate the risk of losing 'climate space' for peatlands in Europe and Western Siberia [2]. Climate change could lead to a significant reduction in suitable peatland areas in permafrost zones. The total area of peatlands affected by these scenarios contains 37.0–39.5 Gt of carbon (equivalent to twice the amount of carbon stored in European forests).
It has been estimated that degradation of peatlands contributes to 5–10% of global annual anthropogenic carbon dioxide emissions.
Rehabilitation of peatlands can help restore many ecosystem functions, including the CO2 storage potential.
Rehabilitation challenges remain. While degraded areas can often be restored to enable net CO2 sequestration, aspects such as biodiversity, water regime, and peat soil structure may not fully recover after years of rehabilitation efforts, potentially weakening ecosystem resilience to future change [1].
Scientists emphasize the importance of restoring degraded peatlands for achieving carbon neutrality and biodiversity protection goals. Further research and monitoring are needed to better understand restoration effectiveness and priorities.
Methods to protect peatlands against drainage.
Protection of peatlands from drainage
Protection of peatlands from drainage includes a range of activities that can be divided into three categories: ecosystem management, technical interventions, and social awareness. These include:
- Restoring the natural groundwater level: This is a fundamental step in peatland protection, often implemented by blocking drainage ditches and canals. These actions aim to prevent excessive water runoff, which is essential for maintaining the natural moisture of peatlands.
- Biotechnical methods: Planting plants that naturally retain moisture and support the structure of peatlands is another important element of protection. These plants help to preserve the integrity of the ecosystem and prevent erosion.
- Strict control over human activity: Limiting the activities conductive to peatland degradation is essential. This includes regulations on peat production and the development of infrastructure in their vicinity.
- Raising social awareness: Education about the importance of peatlands for the ecosystem and climate is important in building social support for their protection. Raising awareness of the role of peatlands in carbon storage, water cycle regulation, and biodiversity contributes to increasing awareness and engaging local communities in conservation efforts.
- Retentive structures: The use of various types of structures, such as dams, drainage barriers, or small retention gates, is important in regulating water levels. These structures allow for controlling water flow and maintaining the appropriate level of moisture in peatlands. Various materials can be used to build these structures, such as wood, steel, concrete, and vinyl sheet piles.
Vinyl Sheet Piles: a solution for sustainable engineering
Vinyl sheet piles, which have been on the market since the 1980s, are an alternative to steel sheet piles. Made from weather-resistant PVC, often derived from recycled materials, they offer a number of advantages from both an engineering and environmental perspective. They are used in a variety of engineering projects involving flood protection infrastructure, water retention structures, construction of port facilities, piers, and retaining walls. The efficiency of PVC piles has been proven in a number of ways. Their efficiency is not limited to cost or aesthetic aspects, but also includes durability [3] and environmental benefits. In a life cycle assessment (LCA), vinyl sheet piles show significantly less environmental impact than traditional steel sheet piles [4]. This is due in part to the fact that more vinyl sheet piles can be produced from one ton of PVC than steel sheet piles from the same amount of steel. In addition, the lower density of PVC makes them more environmentally friendly to transport, enabling the loading of more sheet piles per unit of transport. Vinyl sheet piles also have an advantage in recycling, as they can be recycled even after many years of use, unlike steel sheet piles, which are subject to corrosion.
An important aspect is also the possibility of producing vinyl sheet piles with an integrated gasket made of soft PVC, which ensures their maximum tightness. Locks constructed in this way show a water pressure of 2 bar in laboratory tests.
Vinyl Sheet Piles in Wetland Protection: projects overview
Vinyl sheet piles, due to their properties, have found application in innovative projects related to wetland protection. They are used to create tight anti-filtration barriers that prevent the drainage of groundwater from sensitive peatlands. Below, we present two examples of projects carried out in Europe where vinyl sheet piles were used to protect wetland ecosystems.
The first of the described projects was the protection of a peatland located within the Natura 2000 protected area in the Białe Ługi natural reserve in Southern Poland. In Białe Ługi, vinyl sheet piles with gaskets were driven into the ground to a depth of 3 m, and 1 m was left above the ground to prevent the drainage of water from the critical area.
The second project is located in Sweden and is part of a research study which carried out under the supervision of the University of Gothenburg. The spot where the vinyl sheet piles were installed is currently subject to scientific research. Within this area, which was previously used for intensive peat production, special devices were installed to measure greenhouse gas emissions from peatlands. The sheet piles were placed in such a way as to prevent excessive drainage of water from this area. Additionally, along the route of a natural water collecting ditch, a tight-wall made of PVC piles was installed with a height determined as a result hydrological analyses.
In the case of both of the projects discussed above, the installation of vinyl sheet piles proved to be trouble-free and simple. The profiled were driven into the ground using a backhoe bucket.
It should be noted that the trouble-free installation was due to the properties of peat soil which is soft and does not pose much resistance. When PVC piles are installed in soils such as sands or clays, it is recommended to use special guides to facilitate installation and reduce the risk of pile damage. In the case of the two projects described above, both sheet pile structures were covered with system vinyl caps to improve the aesthetics of the walls.
Summary
Peatlands play an extremely important role in the global climate balance. Unfortunately, these ecosystems are seriously threatened by drainage due to climate change and human activity. This destructive process leads to the release of large amounts of greenhouse gases, mainly carbon dioxide and methane, which accelerates the greenhouse effect and global warming.
In response to the above challenges, modern methods of peatland protection are being developed, among which vinyl sheet piles may play a key role. Their use allows for effective prevention of peatland drainage by controlling the level of groundwater. Thanks to their durability, environmental benefits, and ease of installation, vinyl sheet piles are becoming the preferred solution for protecting peatlands as natural carbon reservoirs, contributing to the fight against climate change.
References:
- Loisel, J., & Gallego-Sala, A. (2022). Ecological resilience of restored peatlands to climate change. Communications Earth & Environment, 3.
- Fewster, R. E., Morris, P. J., Ivanovic, R. F., Swindles, G. T., Peregon, A. M., & Smith, C. J. (2022). Imminent loss of climate space for permafrost peatlands in Europe and Western Siberia. Nature Climate Change, 12.
- Dutta, P.K., & Vaidya, U. (2003). A Study of the Long-Term Applications of Vinyl Sheet Piles. Cold Regions Research and Engineering Laboratory, U.S. Army Corps of Engineers.
- Marcinkowski, A., & Gralewski, J. (2020). The comparison of the environmental impact of steel and vinyl sheet piling: life cycle assessment study. International Journal of Environmental Science and Technology.
- The Pietrucha Group website. "Vinyl Sheet Piling Used to Enhance Retention Capabilities of a Nature Reserve."
- Skogaryd Research Catchment [@SkogarydRC]. "Now the drainage ditches has been blocked and is already filled with water." x.com, August 29, 2022,