Simulated monthly Statistical- dynamical analysis of day degree of pant's growth by EHOM model

The aim of this study was to analyze the effects of global warming on plant growth degree day in the future decades. To this aim, simulated daily temperature data were drawn from EHOM database and under A1B scenario during 2015-2050 from Germany Plank Max. Then, daily degree data were downscaled with a separation of 0.27*.027 degrees longitude and latitude, covering around 30*30 km of Iran, by regional climate model designed at the Abdul Salam Center for Theoretical Physics, Italy. Finally, a matrix with dimensions of 13140*2140 was obtained that rows represent degree day and columns represent stations (cells). The threshold of 5 ° was selected to calculate the growth degree day. Finally, the monthly average of growth degree day was calculated in a matrix with dimensions of 12*2140 in MATLAB software. Then, the map of average of growth degree day was designed through Surfer software. The results showed that June and July had the highest average monthly growth rate in the 100-1000 degree-day. In summer months, the highest degree day was observed in Khozestan plain. With regard to the degree day in spring and summer, Iran can be divided into three areas of mountains and interior foothills, internal pits and external foothills, and plains and southern coast.