بررسی اثرات تغییرات آب و هوا بر عملکرد محصول زعفران در استان خراسان جنوبی با رهیافت پانل فضایی

ایران بزرگترین تولیدکننده زعفران در جهان و استان خراسان جنوبی در جایگاه دوم تولید این محصول در کشور قرار دارد لذا بررسی عوامل موثر بر عملکرد زعفران در این استان حایز اهمیت است. پژوهش حاضر به بررسی اثرات تغییرات آب و هوا شامل اثرات مستقیم و غیرمستقیم ناشی از سرریزهای فضایی دما، رطوبت نسبی و بارش بر عملکرد زعفران در شهرستان‌های استان خراسان جنوبی در دوره زمانی 1390 تا 1402 پرداخته است. داده‌های مربوط به عملکرد زعفران از سایت جهادکشاورزی و داده های اقلیمی از سایت هواشناسی استان خراسان جنوبی اخذ گردید، برآورد و تحلیل داده‌ها به کمک مدل پانل فضایی و با استفاده از نرم افزارstata17  انجام شد. نتایج بر اساس مدلsac که به عنوان مدل بهینه در مدل‌های اقتصادسنجی فضایی انتخاب شده است و به‌طور کلی نشان می دهد شاخص بارش و رطوبت نسبی و شاخص حداکثر دما تاثیر معنی‌داری بر عملکرد زعفران ندارد اما شاخص دما تاثیر منفی و معنی‌دار و شاخص حداقل دما تاثیر مثبت و معنی‌داری داشت. همچنین پارامترهای فضایی نیز همبستگی فضایی مثبت و معناداری را نشان دادند که بیانگر اهمیت اثرات فضایی در تحلیل داده‌ها بود. بر اساس نتایج این پژوهش، با بهبود روش‌های آبیاری و استفاده از تکنیک‌های بهینه کشاورزی، پایش و پیش‌بینی اقلیمی دما و انجام پژوهش‌های بیشتر در زمینه بررسی اثرات تغییرات اقلیمی و سرریزهای فضایی بر زعفران می توان به کشاورزان و سیاست‌گذاران کمک نمود تا با پیش بینی و مدیریت بهتر شرایط اقلیمی، بهره‌وری و عملکرد این محصول را در سال های آتی بهبود بخشند.

examining the effects of climate change on saffron yield in south khorasan province using a spatial panel approach

introduction: one of the greatest environmental challenges of the 21st century is climate change, which has serious economic and social consequences. these changes are the driving force behind global warming, the spread of droughts, and climate anomalies that directly affect agricultural productivity. in iran, the agricultural sector is one of the main pillars of the economy, and the impact of these climate changes is highly noticeable. the arid and semi-arid regions of iran, especially in south khorasan, are clearly affected by these changes. climate analyses indicate that by the years 2025 and 2050, the southern regions of khorasan will experience an increase in average air temperature by 1.5 to 2.3 degrees celsius. saffron, as one of the strategic products and economic advantages of south khorasan, is sensitive to temperature changes and is most affected by climate change. the significance of saffron cultivation in iran is due to its high-water efficiency, job creation in rural areas, prevention of migration, income generation, and the development of non-oil exports. therefore, understanding the consequences of climate change on saffron production and offering solutions to mitigate these effects is of special importance. past studies have shown that temperature and precipitation are among the most significant factors influencing the risk and production of agricultural products, including saffron. many studies have been conducted in this area, most of which focus on examining climate changes in a specific region. however, a limited number of these studies have also considered the indirect effects arising from spatial spillovers in neighboring regions in addition to examining the impact of climatic factors in one area. the aim of this research is to investigate direct and indirect effects of spatial spillovers of temperature, minimum and maximum temperature, precipitation, and relative humidity on saffron yield in the counties of south khorasan over the period from 2011 to 2023. in addition to examining the direct effects of climate change on saffron yield, this study also analyzes the indirect impacts of these changes through spatial spillovers of climatic variables on saffron yield in neighboring regions. the use of spatial econometric methods in this research represents the innovative aspect of this study. materials and methods: in this research, meteorological data from the south khorasan meteorological organization for variables such as precipitation, average temperature, average maximum temperature, average minimum temperature, and relative humidity (percentage) on an annual scale for the statistical period 2011-2023 has been collected. this study was conducted at the provincial level in south khorasan and in 11 counties: boshrouyeh, birjand, khousf, darmian, zirkuh, sarayan, sarbisheh, tabas, ferdows, qaen, and nehbandan. data on saffron yield were also obtained from the agricultural jihad statistics of south khorasan province. a spatial panel model was estimated using stata17 software. results and discussion: the result showed in the sac and sdm models, temperature had different effects: in the sdm model, maximum temperature had a negative and significant impact on saffron yield, while in the sac model, minimum temperature had a positive and significant impact. additionally, relative humidity had a positive and significant impact only in the sem model. the sac model was selected as the optimal model, indicating no significant impact of precipitation and a negative and significant impact of temperature on saffron yield. moreover, minimum temperature had a positive and significant impact. the spatial parameters also showed a positive and significant spatial correlation, highlighting the importance of spatial effects in data analysis. conclusion: based on the results of this study, some recommendations are presented to improve saffron yield in south khorasan province. firstly, temperature management is crucial for saffron cultivation, as increased temperature negatively impacts saffron yield. therefore, it is suggested that farmers use cooling methods, such as shade nets and efficient irrigation systems, to mitigate the negative effects of temperature rise. developing precise climate prediction and monitoring systems can help farmers plan better and adopt appropriate measures to cope with climate change. secondly, although precipitation and relative humidity did not have a significant impact on saffron yield, previous research indicates that water resource management and the use of effective irrigation techniques, especially in low-rainfall areas, can help improve saffron yield. using optimal agricultural techniques and improving planting and cultivation methods can also increase the productivity of agricultural lands. educating farmers in this regard will be very effective as well. finally, it is recommended to conduct more research on the effects of climate change and spatial spillovers on saffron in various regions of the country so policymakers and farmers can make better decisions for managing and improving saffron yield tailored to different climates, ensuring better climate condition management and improving saffron productivity nationwide.