Investigation of Climate Change Occurrence and its Impact on Wheat Growth (Case Study: Fars Province)

The purpose of this study is to predict climate change and investigate the effect of climate change on Growth Day-days and total days of wheat growth in Fars province. For this purpose, the climate data of three synoptic stations of Shiraz, Lar and Abadeh in Fars province and the data of two models HADGEM2-ES and EC-EART were scaled under RCP45 and RCP85 scenarios. LARS-WG statistical model was used for Downscaling. The results showed that the LARS-WG model has appropriate accuracy in Downscaling of Fars province climate, minimum and maximum temperature parameters. The minimum and maximum temperatures of all three stations of Shiraz, Lar and Abadeh increased under both RCP45 and RCP85 scenarios. The increase in the minimum temperature of the base period (1980–2015) in Fars province relative to the period (2021–2040) for the RCP45 and RCP85 scenarios is 1.43 and 1.65 ° C, respectively. The maximum increase in base temperature over this period for the RCP45 and RCP85 scenarios is 1.51 and 1.66 ° C, respectively. The amount of changes in the rainfall of the baseline period increased by 2.93% and 1.95% for the RCP45 and RCP85 scenarios, respectively. Then, using ADP equation, the number of day-index under two temperature thresholds of 4 and 25 ° C for the basic and future time interval (2021-2040) was calculated and the results showed the degree of days of wheat growth period (GDD) and total days’ number. The growth period (DAP) had an increasing and decreasing trend compared to the baseline period