Published: April 14, 2023

Henrik Kalisch, Department of Mathematics, University of Bergen, Norway

Coastal Modeling in Norway: When Shallow Water Runs Deep

For coastal communities around the world, catastrophic storm waves and storm surge events pose the biggest threat to life and property. For these major events, forecasting is relatively reliable, protective structures are in place, and emergency plans are well established. The Norwegian coast is special in that it features sharply sloping topography and extreme depths very close to shore. Under certain conditions, this irregular coastal geometry can give rise to terrain-driven extreme wave events. In fact, we show evidence using mathematical modeling, observations and field measurements that unexpected extreme wave run-up and flooding may occur during otherwise benign wave and weather conditions. These events are episodic in nature and extremely difficult to forecast. We offer possible approaches for more accurate modeling and forecasting with improved shallow-water models, and suggest policy options and procedures to reduce fatalities.