Reducing greenhouse gas emissions through sustainable water and subsurface management
What measures in land and water management can reduce greenhouse gas emissions from water and soil systems while enhancing carbon sequestration? Deltares quantifies greenhouse gas emissions and carbon storage in these systems and develops knowledge and tools in collaboration with a wide range of partners. In doing so, we support policymakers and practitioners in making informed decisions that contribute to climate mitigation and a positive climate impact.
Reducing greenhouse gas emissions is essential to mitigate climate change. The Netherlands has committed to becoming climate neutral by 2050, in line with international agreements such as the Paris Agreement and the Sustainable Development Goals.
As the transition to renewable energy gathers pace and emissions from sectors such as industry and transport fall, emissions from land and water systems remain relatively stable. These systems play a significant role in the exchange of greenhouse gases, including carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). These gases are released through both natural processes and human activities.
Smart management as a key solution
It is difficult to determine precisely how much water and soil systems contribute to total greenhouse gas emissions. However, their relative share is expected to increase as emissions from fossil fuels continue to decline. At the same time, water and soil systems can also serve as carbon sinks. When they store more carbon than they emit, they can make a positive contribution to climate mitigation.
Sustainable land and water management is therefore key. However, a lack of detailed knowledge poses a risk. Unaccounted greenhouse gas emissions can undermine the climate benefits of natural systems and climate mitigation measures.
Finding the right balance
In delta regions, active management of sediments and water levels is essential. At the same time, decisions must balance climate impacts with other societal objectives, such as flood risk management, freshwater availability and biodiversity enhancement.
Deltares investigates how water and subsurface systems can be managed to minimise greenhouse gas emissions while maximising their capacity for carbon storage.
Our work focuses on:
- quantifying greenhouse gas emissions and carbon sequestration in water and soil systems;
- assessing the impact of management measures and interventions;
- monitoring, modelling and validating effects to support policy development and practical implementation.
Challenges
Hidden emissions
Greenhouse gas emissions from water and soil systems are driven by natural processes that vary over time and are influenced by both environmental conditions and management practices. Small changes in water levels, oxygen availability, nutrient concentrations or land use can have major consequences.
Because carbon uptake and greenhouse gas emissions occur simultaneously, the key challenge is determining the net balance between the two. This is often difficult to measure accurately.
Landscape elements
How much do different landscape elements contribute to overall greenhouse gas emissions? Examples include peat meadows, drainage ditches, lakes, rivers, salt marshes and coastal zones.
Research increasingly shows that small water bodies, such as agricultural ditches, can play a disproportionately important role. Understanding the climate effects of different landscape elements helps improve climate-resilient spatial planning and design.
Human interventions
Dredging activities, construction works and nature restoration projects temporarily disturb natural systems and may initially lead to increased greenhouse gas emissions.
Over the longer term, however, these same interventions can improve water quality, enhance biodiversity and increase carbon storage. A sound assessment of climate impacts therefore requires insight into the full trajectory from disturbance to ecosystem recovery.
Unlocking carbon storage potential
How can we maximise carbon sequestration in water and subsurface systems? And how can we prevent carbon emissions from eroding soils? Coastal wetlands and estuarine environments are highly effective carbon sinks because they trap large amounts of fine sediment.
Creating similar conditions through Nature-based Solutions may help remove additional carbon dioxide from the atmosphere. Conversely, erosion caused by sea level rise or human activities can release carbon that has been stored in soils and sediments for centuries.
Peat meadow areas
Peat meadow areas are a major source of greenhouse gas emissions due to peat decomposition, often associated with land subsidence. Raising groundwater levels can reduce emissions, but effectiveness varies depending on local conditions and management practices.
In some cases, rewetting may even increase certain emissions. Other measures, such as alternative land use, can also contribute to emission reductions. Addressing these challenges requires long-term, large-scale and well-coordinated research.
Our approach: measure, understand and apply
Deltares develops innovative strategies for sustainable water and subsurface management using a systems-based approach. We combine:
Field measurements
Continuous monitoring of greenhouse gas emissions across a wide range of landscapes and ecosystems.
Modelling
Simulation of sediment dynamics and vegetation development, for example in salt-marsh systems, enabling the assessment of emissions and management measures at local, regional and national scales.
Laboratory research and experiments
Investigating decomposition processes, carbon stability and the behaviour of both recently captured and long-term stored carbon.
Validation and monitoring
Testing measures under real-world conditions and generating reliable evidence for policy and practice.
This iterative approach—measuring, modelling, understanding, applying and measuring again—produces robust and actionable knowledge. It brings together expertise from hydrology, ecology, microbiology, geochemistry, geology and civil engineering.
From knowledge to policy and design
Greenhouse gas emissions from water and soil systems are still rarely considered in spatial planning and design. In construction and infrastructure projects, efforts often focus on reducing direct emissions through measures such as electrified equipment.
However, decisions regarding location, water level management and land use can have an equally important influence on greenhouse gas emissions.
Deltares supports governments, water managers and spatial planners by:
- identifying where emissions occur and what drives them;
- quantifying the effectiveness of management measures;
- translating scientific knowledge into policy instruments, emission inventories and design principles.
In this way, we help to embed climate mitigation structurally within water and subsurface management.
Projects
NOBV – Netherlands Research Programme on Greenhouse gas dynamics in Peatlands and organic soils
A long-term national research programme coordinated by Deltares that quantifies greenhouse gas emissions from peat meadow areas and evaluates the effectiveness of mitigation measures. The programme aims to reduce emissions from peatlands by one million tonnes of CO₂. It also includes the development of advanced models, such as SOMERS, for national greenhouse gas inventories.
PoKoNaBo - Research into greenhouse gas emissions and carbon sequestration in Nature-based Solutions, including constructed wetlands. Long-term monitoring is used to assess how management practices can enhance carbon storage.
NL2120 - The use of Nature-based Solutions, such as peatland rewetting, to make the Netherlands climate-resilient and future-proof. In the Fryske Hegewarren area, Deltares monitors greenhouse gas emissions, land subsidence, water flows, groundwater levels and soil characteristics.
BlueCAN - Research into greenhouse gas emissions from lakes and the role of small water bodies. The project also explores the use of DNA-based techniques to better understand biological processes linked to greenhouse gas production and consumption.
DuNag / LandSeaLot / RESTCOAST - Research into greenhouse gas emissions and carbon storage in sediments, coastal systems and transitional environments, including the effects of sand extraction and coastal restoration measures.
Greenhouse Gas Facility
Deltares is one of the partners in the FTO Sustainability programme. Within this programme, new experimental facilities are being developed for research into climate change, greenhouse gas emissions and air pollution.
As part of this consortium, Deltares is expanding its greenhouse gas research capacity into a dedicated Greenhouse Gas Facility. The facility enables targeted research into the interactions between water, soil and air, greenhouse gas emissions, and the effectiveness of mitigation measures.
The Greenhouse Gas Facility includes advanced equipment for measuring greenhouse gases and air quality, making it possible to determine total greenhouse gas emissions and assess the impact of measures aimed at reducing them.
The facility combines:
- expanded instrumentation in the Delta-lab (micro scale)
- equipment for in-situ measurements (meso scale)
- field monitoring systems (macro scale).
Together, these specialised instruments and research methods can be deployed across a wide range of projects and environments. Like Deltares' other research facilities, the Greenhouse Gas Facility is not only intended for our own research. It is also available for collaboration with knowledge institutes, governments and industry partners.
