Long Lead Flood Simulation Using Downscaled GCM Data in Arid and Semi-arid Regions: A Case Study

Document Type : Research Paper


1 Professor, School of Civil Engineering, University of Tehran, Tehran, Iran

2 M.Sc., School of Civil Engineering, Amirkabir University of Technology, Tehran, Iran

3 Ph.D. Candidate, School of Civil Engineering, University of Tehran, Tehran, Iran


Flood is one of the most calamitous natural disasters that causes extensive property and life damages across the
world. It however, could be a blessing due to its special natural water resources recharging value. By simulating the
magnitude of probable floods considering the anthropogenic and natural effects and implementing contingency plans,
their damages could be reduced. In this paper, the General Circulation Model (GCM) climate change scenarios are
employed to simulate future floods. The GCM scenarios include simulation of climatic signals of the future
considering green house gas emission forces. In this study a statistical downscaling model (SDSM) has been applied
for rainfall downscaling to provide regional results from GCM outputs. Then, a rainfall-runoff model called HECHMS
has been employed to estimate runoff in the region. The maximum simulated rainfall for each year that is of
high enough potential to cause flood, is introduced into the rainfall-runoff model to simulate the plausible
hydrograph of the flood. The proposed procedure is applied to the Kajoo River basin in South Baloochestan region,
south-east of Iran.