Recently, Due to Climate change, extreme rainfall occurs frequently. In many preceding studies, Because of extreme
hydrological events changes, it is expected that peak flood Magnitude and frequency of drainage infrastructures changes.
However, at present, probability rainfall in the drainage facilities design is assumed to Stationary which are not effected
from climate change and long-term fluctuation . In the future, flood control safety standard should be reconsidered about the
valid viewpoint.
In this paper, in order to assess impact of climate change on drainage system, Future climate change information has been
extracted from RCP 8.5 Climate Change Scenario for IPCC AR5, then estimated the design rainfall for various durations at
return periods. Finally, the design flood estimated through the HEC-HMS Model which is being widely used in the
practices, estimated the effect of climate change on the Design Flood of Mihochen basin. The results suggested that the
Design Flood increase by climate change. Due to this, the Flood risk of Mihochen basin can be identified to increase
comparing the present status.