KRIM - Climate Change and Preventive Risk and Coastal Protection Management on the German North Sea Coast | Umweltbundesamt

Regional differentiation by downscaling from the global ECHAM4 / OPYC3 model with IPCC scenario IS92a;

Rise in atmospheric CO2 content to 2 x 360oom; average annual temperature increase of 2.7°C with seasonal differentiation; increase in precipitation by +10% with seasonal differentiation; wind speeds +3.8% with seasonal differentiation; wind-related increase in high tide levels; change in sea levels and tidal range (average high tide +65cm, average low tide +40cm);

Study of the increase in the probability of failure of coastal protection facilities and assumed dyke breaches, the damage resulting from flooding (property damage, ecological damage) and economic consequences for gross value creation and employment figures, changes in the hydrology and morphology of the Weser and in the coastal zone and tide lands, and the ecological effects on floodplains and inland areas and their ecosystem services for social user groups (primarily coastal protection, agriculture, conservation).

The sensitivity of coastal floodplain ecosystems to accelerate sea level rises is rated as high in some cases and its resilience as limited, although uncertainty prevails. The sensitivity of inland ecological systems used for agriculture is comparatively low. In generally, the project is studying the possible effects of climate changes on nature and society, with the objective of identifying the ecological and socio-economic sensitivities and facilitating preventive action. Analysis of scientific and social science relationships and their climate sensitivity can make a contribution to future management in coastal protection.

Technical and organisational adaptation capacity in coastal protection is high due to historical experience.

In case of failure of the coastal protection facilities, significant geographical differences in the potential damage can be identified, which are not taken into account in current practice for assessment of coastal protection systems; the principle used is: identical security for all or an identical level of fail safety everywhere. In addition, even if the probability of failure is kept constant by strengthening the dykes, a higher sea level leads to an increase in potential damage, as more water can flow in. Therefore, the financial requirements for coastal protection will increase in the future with accelerated sea level rises.

Long planning and implementation periods in coastal protection demand prompt action.

Accelerated sea level rises reduce the current level of security on the coast. For example, climate change related changes in the topography of tide lands and floodplains lead to a greater strain on the main dykes. This requires adaptation measures in coastal protection, in order to maintain future dyke security. Natural adaptation processes that reduce the probability of dyke failure are growth in tide lands and floodplains.

Despite the need for further development, probabilistic risk analysis (with an extended concept of damage) is fundamentally suitable for obtaining planning related conclusions about existing and (in conjunction with the scenario technique) future risks. There are various strategies that can be used to adapt the coastal protection system to the accelerated sea level rises. Of these, strengthening existing facilities is often the option with the most favourable cost/benefit ratio and the highest acceptance. Cost/benefit analyses can supply additional information to support decisions when comparing different coastal protection alternatives.

There are conflicts between conservation, agriculture and tourism in terms of the use of ecological services. Interaction between academics is comparatively harmonious. Discussions within the policy and administrative system are susceptible to conflict in some cases.