The study area, with arid to semi-humid climates, is located in northern Fars Province, southern Iran. Daily precipitation and temperature data from 22 models of the Coupled Model Inter-comparison Project Phase 5 (CMIP5) are used to study climate change for period 2026–2085 under RCP2.6, RCP4.5, and RCP8.5. Daily outputs of each CMIP5 model are downscaled to climatic stations over the study area using LARS-WG tool and transient change factors approach. Daily precipitation is downscaled to seven climatic stations while daily temperature downscaled to two stations. Downscaling results indicate that temperature will increase by + 1.85, + 2.5, and + 3.45 °C under the RCP2.6, RCP4.5, and RCP8.5, respectively, while precipitation will reduce by 14, 22, and 20.8%, respectively, within the study area. Standardized precipitation index (SPI) analysis, performed for 3-, 6-, 9-, and 12-month time scales, shows that frequency (duration) of normal periods will increase (decrease) under climate change, however, 12-month SPI analysis shows decreased frequency and increased duration for normal periods. Frequency, duration, severity, and intensity of wet periods may increase, decrease, or not change under climate change, depending on the SPI time scale. The study area will experience more frequent, longer-duration, severed, intensified droughts in the future due to global warming. Extreme storm analysis shows that precipitation depth of most frequent storms (2-year return period storms) will increase, but precipitation depth of less frequent storms (10- and 20-year return period storms) will decrease under climate change. Temperature enhancement, precipitation reduction, and longer-duration, severed, intensified droughts will increase water shortage in the future, resulting in water crisis and reduced security of food production over northern Fars Province.

干旱至半湿润气候的研究区位于伊朗南部法尔斯省北部。来自RCP2.6，RCP4.5和RCP8.5的耦合模型比较项目第五阶段（CMIP5）的22个模型的每日降水和温度数据用于研究2026年至2085年期间的气候变化。使用LARS-WG工具和瞬态变化因子方法，将每个CMIP5模型的每日输出缩减到研究区域的气候站。每日降水量降级到七个气象站，而每日温度降级到两个气象站。降级结果表明，在RCP2.6，RCP4.5和RCP8.5下，温度将分别升高+ 1.85，+ 2.5和+ 3.45°C，而降水量将分别降低14、22和20.8％。 ，在研究区域内。标准化降水指数（SPI）分析，在3个月，6个月，9个月和12个月的时间尺度上执行的结果显示，正常时期的频率（持续时间）在气候变化下会增加（减少），但是12个月的SPI分析显示，正常时期。根据SPI的时标，在气候变化下，潮湿时段的频率，持续时间，严重性和强度可能会增加，减少或不变。由于全球气候变暖，未来该研究地区将经历更频繁，持续时间更长，更严重，更严重的干旱。极端风暴分析表明，在气候变化下，最频繁发生的风暴（两年回返期风暴）的降水深度将增加，而不经常发生风暴（10年和20年回返期风暴）的降水深度将减小。温度升高，降水减少和持续时间延长，