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

Abstract

Flood is one of the most calamitous natural disasters that causes extensive property and life damages across theworld. It however, could be a blessing due to its special natural water resources recharging value. By simulating themagnitude 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 areemployed to simulate future floods. The GCM scenarios include simulation of climatic signals of the futureconsidering green house gas emission forces. In this study a statistical downscaling model (SDSM) has been appliedfor rainfall downscaling to provide regional results from GCM outputs. Then, a rainfall-runoff model called HECHMShas been employed to estimate runoff in the region. The maximum simulated rainfall for each year that is ofhigh enough potential to cause flood, is introduced into the rainfall-runoff model to simulate the plausiblehydrograph of the flood. The proposed procedure is applied to the Kajoo River basin in South Baloochestan region,south-east of Iran.

Keywords

• downscaling
• flood simulation
• rainfall-runoff model
• gcm