COST ESTIMATION FOR RESIDENTIAL RELOCATION IN ADVANCE OF SEA LEVEL RISE IN JAPANESE COASTAL AREAS

Abstract

 This study proposes a method for estimating the cost of residential relocation, one of the adaptive measures being considered in response to expected sea level rise due to climate change. A reliable and valid cost estimation method was developed by following the conventional scheme of the “Project for promoting community relocation for disaster prevention” and by using the abundant existing empirical data on the costs of civil engineering works. Using SSP1-2.6(SSP1-RCP2.6) and SSP5-8.5(SSP5-RCP8.5) as typical combination of climate and socioeconomic scenarios, this study estimated the costs required to relocate the inundation-affected population under each scenario. As a result, the total cost of residential relocation under SSP1-2.6 was estimated to be approximately 92-183 trillion yen in 2050 and 121-274 trillion yen in 2100. Similarly, the total cost under SSP5-8.5 was estimated to be approximately 105-215 trillion yen in 2050 and 210-501 trillion yen in 2100. Tokyo accounted for the majority of the cost. The relocation cost of this study was higher than the protection cost of the previous study.