The effect of climate change on the discharge of 3 special Qanats in Khosf city

Changes in temperature and rainfall have a large impact on the quantity and quality of water resources, In this research, the effects of climate change on the development of special Qanats in Khusf city (Giw, Mazhan and Vahad Abad) were investigated. For this purpose, minimum and maximum temperature and precipitation were firstly estimated in the two near future (2030-2060) and far future (2070-2100) using the CANESM2 large scale model and two emission scenarios of RCP4.5 and RCP8.5. These data were then quantified by two downscaling models of LARS-WG and SDSM. Using rainfall data for the upcoming period, Discharge value for 3 Qanats were estimated for future periods. The results showed that the minimum and maximum temperatures in the RCP8.5 scenario would be higher than RCP4.5 in the results of both downscaling methods and will increase for both future periods. Rainfall also has slight variations for two scenarios of RCP8.5 and 4.5 for the upcoming period and the base period. Also, comparing two methods of downscaling, the LARS-WG model estimates the temperature changes less than the SDSM model and less changes in rainfall. The results of Qanat change in the upcoming period also showed that in all qanats, the discharge average for the coming period is less than the base period. Also, the RCP4.5 scenario compared to RCP8.5 in two methods of LARS-WG and SDSM is estimated to be greater. Given the changes in discharge in the future, management strategy can be adopted to deal with possible droughts.