Climate change effect on the rainfall amount and intensity in the southern coast of the Caspian Sea

Rainfall properties is impacted by climate change that includes change in number of wet days, duration, intensity and amount of precipitation. This article shows impact of climate change on intensity and rainfall amount in south coast of Caspian Sea. In this research, rainfall is estimated by the aid of HadCM3, A1B and LARS-WG for triple periods 2011-2030, 2045-2065 and 2080-2099. According to estimation results, average precipitation will increase but there is not any evident pattern for monthly scale in study stations. Additionally, according to results, seasonal rainfall changes will increase in winter and in contrary, it will decrease in summer. Intensity simulation results by IDF curves determine that maximum 30-minute intensity will increase in future periods in compares with observational periods except Babol station. In addition, the maximum and minimum 30-minutes intensities in studied return periods, 2, 5, 10, 20, 50, and 100 years are belonged to Anzali and Sangdeh, respectively. Furthermore, maximum 30-minutes intensities in studied return period of 100 years will be %38 will occur in Gorgan in 2080-2099 and minimum will be %0.88 that will occurred in Behshahr in 2030-2011 Finally, this research shows that precipitation events will exacerbate in future periods, which will have consequence in runoff, percolation, sediment and soil erosion in south coast of Caspian Sea that it needs to proper planning for more adaption to climate change in Iran northern region.