Study on PMP estimation for the flood risk evaluation of hydropower dams in consideration of the future climate change

Abstract

It is important for hydropower dams to estimate PMP (Probable Maximum Precipitation) appropriately and to prepare the plan of facilities modification and operational changes in advance, because the future flood risk by climate change influence is getting higher. In this paper, we compared three methods of PMP estimation, the conventional method applying DAD (Duration Area and Depth) analysis based on the experienced rain results, the product of d4PDF (database for Policy Decision making for Future climate change) that is the latest climate model ensemble prediction, and the pseudo-global warming experimental results on the typhoon. It was showed that PMP by d4PDF and the pseudo-global warming experimental results were larger than that by DAD analysis and fluctuated smoothly and reasonably over time. It is preferable and reasonable to evaluate the PMP risk applying DAD analysis at the rough examination, and the estimations applying d4PDF or pseudo-global warming scenario is suitable for more detailed examination.