Estimation of Vulnerability of Coastal Regions Using the Central Pressure of Typhoon Based on Global Climate Change

Abstract:

Typhoons strike the Kyushu Island in the west of Japan a few times a year. Damage of the maritime structures by storm surges and wind waves induced by typhoon frequently occurs in the western prefectures, for example, Kumamoto Prefecture. The coastline in this prefecture is complex. It faces open and closed seas. The coastline is divided into 4 coastal regions in this paper. Each coast has different topographical characteristics.

Using data on the damage of maritime structures caused by typhoons during past 25 years from 1980 to 2004 and the path and central pressure of typhoons during past 110 years from 1902 to 2011, damage of 4 regions along the coast line of Kumamoto Prefecture in Japan for 13 groups of typhoon with different paths is estimated. All typhoons had passed through an area delineated by a latitude of 30° N and 35° N and at a longitude of 127° E and 132° E.

The improved Central Pressure (iCP) Method can be used to estimate the damage of maritime structures that will occur along the coast before typhoon strikes. The improved Central Pressure Method is developed based on the 25 years from 1980 to 2004. The estimation of the damage is done using the central pressure of typhoon at a latitude of 30° N. To develop the central pressure method considering the influence of global warming, the data of the central pressure of typhoons based on the 100 years more term is needed. The trend of the depression of central pressure due to the global warming is discussed using the central pressure based on the 110 years term typhoon data. Furthermore, the risk of each coastal regions in a future is estimated using the increasing or decreasing value of central pressure which is determined on this period data.