Changes in agricultural climate indices based on climate change scenarios in Lorestan province

The occurrence of any possible change in the future climate will seriously change agricultural production at various levels and will be able to significantly change the crop systems that have evolved under the current climatic conditions. The aim of this study is to investigate the changes in key indicators of agricultural climate based on temperature in the context of climate change. This achieve the aim, the spatio-temporal variations in extreme temperature indices in the current conditions (1986–2016) and under scenarios of RCP4.5 and RCP8.5 (2020–2070) was analyzed based on observed data and climate models in Lorestan province. The agro-climate indices related to temperature are consists of Daily Temperature Range, Frost Days, Days with temperatures below -20 °C, Length of Growing Season and Growing Degree Days. The results indicate that the Daily Temperature Range is approximately -0.4 °C decreasing and 0.3–0.9 °C increasing in the current situation and in the RCP8.5, respectively. Indices of Frost Days and Days with temperatures below -20 °C will decrease by about 20 days in the future compared to the current condition. Compared with the current situation, Length of Growing Season and Growing Degree Days will increase by an average of 60 days a year and by about 300 degrees in the future, respectively. In general, in the future, the warm and cold periods of the year will increase and decrease, respectively. This leads to an increase in evapotranspiration and a decrease in soil moisture and a reason to reduce water storage and ultimately reduce crop yield.