気候変動の不確実性を考慮した長期的な治水計画に対するリアルオプション分析の適用

抄録

It is expected that rainfall and frequency of torrential rain will increase in future due to the global warming. Therefore, flood control infrastructures should be developed to deal with the increased future rainfall. However, there is large uncertainty about how fast the global warming progresses and how high temperature increases. Therefore, it is difficult to decide on the level of future rainfall in advance to evaluate the investment projects of flood control infrastructures. With this background, this study proposes a method to apply real options analysis to investment planning of flood control infrastructures under the uncertainty of future climate change. The analysis finds the investment planning which minimizes the expected net present value of the sum of the investment cost and the flood damage, taking account of the all possible future scenarios of temperature change. This study applies the proposed method to assess the investment projects of flood control infrastructures in a river basin of Japan to confirm its validity.