In this study, precipitation- and temperature-related indices were considered using Rclimdex software to study trend of climate extreme indices. Daily minimum and maximum temperature data retrieved from MPI-ESM-LR and ACCESS1-0 global climate model were used to predict future climate extreme events over the next three periods of 2026–2050, 2051–2075, and 2076–2100 based on IPCC scenarios of RCP4.5 and RCP8.5 of studied area covering South Khorasan province and southern part of Razavi Khorasan province, located in east of Iran; furthermore, future saffron yield was predicted based on the yield-extreme indices model. Results showed an increasing trend of warm climate extreme indices and a decreasing trend in precipitation indices as important factors in the decrease of saffron yield. Considering multiple regression yield model of saffron based on climate extreme indices, it was concluded that saffron yield decreases in future periods over studied area with the highest reduction of 31% in period of 2076–2100 under RCP8.5 scenario. Results also confirmed that yield reduction in all three periods under RCP8.5 scenario was greater than the same periods under RCP 4.5 scenario.

在这项研究中，使用Rclimdex软件考虑了与降水和温度有关的指数，以研究气候极端指数的趋势。根据IPCC情景，从MPI-ESM-LR和ACCESS1-0全球气候模型中获取的每日最低和最高温度数据用于预测未来2026-2050年，2051-2075年和2076-2100年这三个时期的未来极端气候事件研究范围的RCP4.5和RCP8.5覆盖伊朗南部以南的霍拉桑省和拉扎维·霍拉桑省的南部；此外，基于产量极限指数模型预测了未来的藏红花产量。结果表明，温暖的极端气候指数呈上升趋势，而降水指数呈下降趋势，这是藏红花产量下降的重要因素。考虑基于气候极端指数的藏红花多元回归产量模型，得出的结论是，在RCP8.5情景下，研究区域的藏红花产量在未来一段时间内下降，在2076年至2100年期间最高下降31％。结果还证实，在RCP8.5方案下，三个时期的减产幅度均大于在RCP 4.5方案下，同期的减产幅度。