Rhine-Meuse delta
The Rhine-Meuse delta in the Netherlands is subsiding due to the drainage of agricultural soils. This has been causing an increase in economic damage, flood risk and greenhouse gas emissions.
Urgency
A recent report of the Council for the Environment and Infrastructure, an advisory board of the Dutch government, showed that drainage in rural peat areas is "in the long term, economically, ecologically and socially irresponsible". It emphasizes the need for action, especially since mitigating subsidence is coupled to other national challenges, such as housing, climate and nitrogen emission issues. However, until now, land subsidence has not yet been a priority of the government and urgency is mostly felt by people experiencing the direct effects of subsidence.
Current policy approach
Simultaneously tackling subsidence and greenhouse gas emissions
In the national climate agreement, it has been decided to reduce greenhouse gas emissions from peatlands by 1 Mt/year in 2030, thereby also addressing the problem of subsidence. Greenhouse gas emissions and subsidence can jointly be reduced by adapting water management and spatial planning. Measures in urban areas mainly focus on adaptation, such as raising cities and using the sewage system as a drainage option, whereas measures in rural areas largely focus on mitigation e.g. by increasing groundwater levels ('rewetting').
Recently, a roadmap towards a national subsidence programme was sent to the Dutch government
However, measures that are currently being implemented are often a result of cost-benefit analysis and do not come from a national policy framework explicitly tackling land subsidence. Only a few local and regional authorities have included subsidence in their policy agendas. Gilles Erkens, researcher in land subsidence and geomorphology, explains, "Recently, a roadmap towards a national subsidence programme was sent to the Dutch government. It presents recommendations for e.g. formulating long-term policy objectives, validating knowledge and improving cooperation between different stakeholders".
Recommendations from the LOSS project
The 6Ms towards sustainable decisions
Within the Living On Soft Soils (LOSS) project, the Water, Climate and Future Deltas hub is contributing to creating integrative knowledge on land subsidence and therefore the required conditions for policymakers to make decisions to accelerate adaptation and mitigation action. By using the 6Ms (measure and model subsidence, understand mechanisms, cost-benefit analysis, and take and monitor measures) as a relatable tool for policymakers and stakeholders, researchers can communicate their results from different research areas and provide clear action perspectives.
Legal instruments
As part of the LOSS project, the PhD project of Martijn van Gils addresses the legal aspects of land subsidence, assessing which legal instruments can be used to stimulate policy development and to implement those policies. Improving the coordination between responsible authorities and formulating clear objectives could be two of the most important future steps. Which governmental level policy objectives should be formulated and legal instruments should be used may differ. For rural areas, policy on a national or provincial level would be effective whereas the characteristics of cities leave room for distinctive local policies.