Abstract
Four sequential typhoons caused severe floods over many river basins in Hokkaido during the middle to latter half of August in 2016. This study investigated spatial and temporal rainfall distribution at a upper reach of Sorachi river basin where a flood occurred due to the typhoon 10th (Lionrock). Furthermore, Uncertainty of rainfall amount over 235 catchments in whole Japan was investigated. Eventually, uncertainty of river discharge associated with spatial distributions of rainfall observation and its of ensemble members from 2 days were quantified. As a result, its associated with spatial distributions of rainfall observation is larger than its of ensemble member.
