Low polders and high waters

Abstract

It is no secret that the climate is changing, however, the severity and speed of this process is under debate. This leads to the question if and when we need to take action to protect the Netherlands against the effects of climate change. In order to deal with the uncertainties in policy- and decision-making, an adaptive approach is desirable. An option is to apply the Dynamic Adaptive Policy Pathways (DAPP) approach.

The DAPP approach has been applied successfully in several large scale projects. However, less attention is given to the application on small scale areas, and no applications on (small-scaled) polder areas are present. The aim of this report is to answer the following research question: "Is the Dynamic Adaptive Policy Pathways approach suited for improving the adaptivity of polder management, given the uncertainty in climate change effects?" The Zuidplaspolder is used as a case area for application of the DAPP approach. This deep-lying polder is interesting due to its diverse land use, the low elevation levels and already present issues in water management.

Through assessing the potential effects of climate change, conducting interviews, creating a hydrological model and following the steps of the DAPP procedure, a pathway map for the Zuidplaspolder is created. This pathway map is evaluated during focus groups with stakeholders from the Zuidplaspolder case area, as well as actors from a different polder area, being the Schermerpolder. Besides evaluating the applicability of the pathway map, the DAPP approach itself was assessed as well.

The pathway map provided several insights, one being the requirement to start considering actions at present in order to timely cope with issues in the future.
Moreover, it was found that the DAPP approach is suited for improving the adaptivity in polder management, given the uncertainty in climate change effects. The pathway map is a helpful tool for authorities and affected stakeholders within polder areas to explicate upcoming issues. However, a cost-benefit analysis is required for actual, well-informed policy- and decision-making based on the pathway map. Nonetheless, it assists in making decisions more strategically and to explain certain choices in decision-making, which helps in creating support and understanding. Even though there are difficulties in translating large-scale actions and their effects to a smaller scale, the scale of the case area proved not to be a major issue. At last, the DAPP approach is found useful for other polder areas as well. However, a general pathway map cannot be created, since each polder has its unique set of characteristics and stakeholders with mindset on urgency.

When the pathway map is utilised for actual policy- and decision making, the use of an extended model is recommended. Here, probabilistic simulations are suggested, as well as the incorporation of several components that were excluded in this research. For identifying an integral pathway map for Dutch polder areas, it is recommended to research the clustering of polder characteristics on their constraints and related measures. By selecting the clusters that fit a designated case polder, a tailored pathway map can be created.