World-wide coastal zones are subject to physical and societal changes. Due to climate change sea level is expected to rise and storm conditions may become more intensive. Both may lead to shore erosion intensification in the coastal zone. Moreover, the coastal zone is intensely used for societal development. The pressure upon the coast increases. It may be questioned whether coastal defence is compatible with spatial development in the coastal zone. To guide the consequences of climate change and the societal developments in a responsible manner, spatial decisions have to be taken cautiously. A long-term coastal vision is important to ensure safety in the future and to gain as much profits from the economic opportunities offered by the coastal zone as possible.
This problem is resolved here by an economic optimisation method. Long-term coastal policies are economically assessed with a stochastic economic optimisation model. This model combines the hydraulic and morphological processes in the coastal system with the maintenance measures and the socioeconomic and ecological activities. The maintenance costs in relation to the possible damage resulting from coastal recession are optimised with the model. The model is influenced by various uncertainties, which affect the optimisation results. Therefore, uncertainty distributions have been assessed and Monte Carlo simulations are made with the model.
The model is applied to the Dutch coast. The expected minimal total costs of various coastal policies are estimated. Optimisation results show that coastal defence and societal activities in the coastal zone in the Netherlands are indeed compatible.