Climate Change Adaptation in Tokyo Bay: The Case for a Storm Surge Barrier

Abstract

Increases in typhoon intensity and sea level rise could pose significant challenges to coastal defences around Tokyo Bay. In order to analyse the extent of future problems the authors determined the increase storm surge that could result from an increase in typhoon intensity and sea level rise to this area around the turn of the 21 st century. Resultsshow how the various settlements around Tokyo Bay are at considerable risk of storm surges and sea level rise in the future. If defences are breached the potential direct economic consequences could be significant, potentially in excess of 100 trillion yen, with the indirect costs likely to be even greater. As a result it is likely that sea defences will have to be strengthened around Tokyo Bay in the future, which could cost in the order of 370bn yen to defend against a 1 in 100 year storm by the year 2100. Alternatively, a storm surge barrier could be built, which would be more expensive (possibly in the range of 700-800bn yen), though it could increase the protection level and would be able to cope with 1 in 200 or 500 year events, amongst other benefits.

Climate Change and Adaptation Planning for Ports

“…An alternative to this could be the construction of a storm surge barrier or permanent lock at the entrance of Tokyo Bay, which could somehow reduce the extent of this problem by allowing water levels to be controlled though also slowing the passage of ships (Esteban et al, 2014a). Essentially, stronger tropical cyclones and their associated storm surges, together with the long-term effects of sea level rise could lead to the inundation of many port areas.…”

“…Aside from damaging winds, these weather systems also generate powerful waves and storm surges, which can inundate coastal areas and lead to the destruction of property and the loss of lives, as shown by the devastating damage caused by typhoon Haiyan in the Philippines in November of 2013 (Takagi et al, 2014). Tropical cyclones form in subtropical latitudes with high surface sea temperatures, using the heat from the evaporation of sea water to maintain or increase their strength, and then propagate away to higher latitudes.…”

Implications of climate change for shipping: Ports and supply chains

“…However, the key to these is incorporating multiple stakeholders into the adaptation process, from engineers, to planners, insurers, regulators and others (Table 1). As impacts of climate change become more profound, many port communities will need to consider more transformational adaptation strategies (Esteban et al, 2014;Kates et al, 2012). For example, there are three major adaptation responses to sea level rise: elevate, defend, or retreat (Aerts et al, 2014;Cheong, 2011;Kates et al, 2012).…”

A method to estimate climate-critical construction materials applied to seaport protection

“…As projected changes in sea level and storm intensity progress through this century and beyond, many coastal decision makers, particularly those with responsibility for port operations and development, will likely implement transformational adaptation strategies (Esteban et al, 2014;Kates et al, 2012) such as one of three major adaptation solutions: elevate, defend, or retreat (Aerts et al, 2014;Cheong, 2011;Kates et al, 2012). Elevating a port typically entails filling the port lands to raise them above the floodplain, reconstructing facilities at the new elevation, and designing a system to accommodate the difference in heights between the water level and the port infrastructure (MSPA, 2007).…”