On 11 March 2011, a tragic tsunami hit and destroyed large parts of the Japanese coastal area. The tsunami was a result of an earthquake, measuring as high as 9.0 on the Richter scale and leaving extensive damages in its wake.

In Higashi Matsushima city, the height of the tsunami wave surpassed 10 m, propagated as far as 5 km inland. It claimed the lives of 1,039 victims of a population of 42,000, and destroyed more than 60% of the city.

Since then, DHI has, together with the Danish Authorities and especially the Royal Danish Embassy in Japan, provided assistance to Higashi Matsushima city, which was one of the most severely affected communities along the coastline of the Tohoku region.

DHI offered assistance through modelling of the tsunami. Accurate modelling is very important in developing reliable disaster warning systems and in the planning of the reconstruction of the affected areas.
The simulations were performed using MIKE 21 HD, and the initial results of the modelling are used by local authorities to identify safety areas for the reconstruction.
The area covered is 1000 km2 for 45 km of coastline, and with grid resolutions of 50 m and 10 m.

The model results have proven in agreement with available information and observations.