عنوان مقاله [English]
The global warming and climate changes, based on the results of related studies and research, have potential effects on precipitation and temperature fluctuations which the impact of these fluctuations is significant on various sectors such as water, agriculture and the management of urban runoff collecting. So, the forth report of Intergovernmental Panel On Climate Change is downscaled in order to provide the outlook of future changes in extreme events specially precipitation and temperature by using the output of three atmosphere general circulation models (HadCM3, CNCM3, NCCCSM) based on A1B, A2 scenarios. The precipitation indexes under investigation in this research include (PRCPTOT, R10mm, R20mm, R95p, R99p, RX1day, RX5day,SDII ) and temperature indexes include (SU35, TN10P, TNn, TNx, TR20, Tx90p, TXx) calculated for said coming futures. The results show that it's likely the maximum average of five days precipitation and intensity of precipitation increase under A2 scenario during coming future 2011-2030.As well as a larger share of the total annual rainfall will be belonged the occurrence of torrential rains and showers namely showers over 95th and 99th percentile of base period. According to the obtained results, increasing of the indexes would mean the increasing of frequency and severity of floods specially during coming period 2011-2030. While all the studied extreme indexes increase during 2011-2030 ,so that it’s predicted SU35 and TR20 indexes would increase based on A1B scenario 17and 15 respectively and based on A2 scenario 13 days respectively.