ANALYSIS ON FUTURE CHANGES OF RAINFALL PATTERN USING A LARGE-EMSEMBLE DATASET

In recent years, record-breaking rainfall has been occurring frequently due to climate change, causing extensive damage in many areas. It is important to properly assess future changes and take adaptive measures to cope with such heavy rainfall. In Japan, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has been promoting flood control planning using large ensemble climate prediction data. The data can be used for flood risk assessment based on the spatiotemporal distribution of rainfall. In this study, future changes in rainfall waveforms, which are important for flood risk assessment, were analyzed. It was shown that the proportion of backward-concentrated rainfall increases as the rainfall duration increases, and that there is a tendency for future events with rainfall intensity of 15 to 20 mm/h to continue falling for a long time. In comparison with the actual measurements, the rainfall waveforms of the future experiment generally agreed with the actual measurements, and the peak rainfall intensity tended to increase compared to the actual measurements.