بررسی وضعیت تغییرات دمایی ایران نسبت به دوره استاندارد اقلیمی بلندمدت گذشته

پدیده های طبیعی و فعالی تهای انسانی، دو عامل اساسی در تغییرات دما در جهانمحسوب می شوند. تغییرات دما می‌تواند به دو صورت طبیعی یا ناشی از فعالیت‌های انسانی )مانند انتشار گازهای گلخانه‌ای( رخ دهد. با توجه به اهمیت تغییرات دمایی و ارتباط آن با تغییرات اقلیمی، این مقاله با بهره گیری از روش‌شناسی مبتنی بر روش تحلیلی و توصیفی سه سطحی در سطح اول تغییرات دمایی در پهنه کشور با بهره گیری از داده های شبکه ای پایگاه cru و اتکا بر روش تحقیق کمی ، در سطح دوم واکاوی علل کلی افزایش دما در کشور با اتکا به روش تحقیق کیفی و در آخرین سطح، واکاوی فرصت‌ها وتهدیدهای ناشی از افزایش دما در بخش کشاورزی با اتکا به روش تحقیق کیفی را بررسی کرده است. نتایج نشان میدهد که افزایش دما در متوسط حداقل دما و حداکثر دما در دوره سی ساله اخیر نسبت به دوره استاندارد اقلیمی انتخابی کاملا مشهود بوده است. افزایش دما در حداقل دما نسبت به دوره استاندارد اقلیمی انتخابی در عین اینکه افزایشی بوده است، نسبت به حداکثر دما نیز بسیار بیشتر بوده است. این موضوع، فرصتی را برای گسترش تولید محصولات کشاورزی و افزایش تنوع کاشت فراهم می‌کند. همچنین افزایش دما می‌تواند به کشاورزان مناطق سردسیر این امکان را بدهد که الگوی کاشت خود را تغییر داده و محصولات گرمادوست را نیز کشت نمایند. تهدیداتی همچون افزایش تبخیر، افزایش تبخیر-تعرق و ایجاد شرایط برای تکثیر و ازدیاد جمعیت حشرات مضر و افزایش هزینه های سرمایشی گلخانه ها و موارد دیگری را به همراه داشته باشد.

investigation of iran’s temperature changes compared to the pas t long-term climatic standard period

introductionnatural phenomena and human activities are considered among the mos t important factors influencing global temperature changes. these changes can occur either naturally or due to human activities, such as the emission of greenhouse gases. given the significance of temperature changes and their impact on climate change, this article aims to thoroughly examine temperature changes in iran over s tandard climatic periods and analyze their effects on various sectors, particularly agriculture. materials and methodsthe main objective of this research is to s tudy the trend of temperature changes in the country at three levels: 1) temperature changes across the country, 2) analysis of the overall causes of temperature rise, and 3) analysis of the opportunities and threats posed by rising temperatures in the agricultural sector.this research employs a mixed methodology that includes both quantitative and qualitative approaches. at the firs t level, the country’s temperature changes are analyzed using network data from the cru database, which is a reliable source of global climate data. these data cover two s tandard climatic periods: 1961-1990 and the recent period of 1990-2020. temperature analyses have been conducted using s tatis tical methods based on average, maximum, and minimum temperature data. at the second level, a qualitative research approach has been utilized to inves tigate the general causes of temperature rise in the country. this analysis examines the effects of greenhouse gases, land-use changes, and other human and natural factors.at the third level, the research evaluates the potential opportunities and threats arising from increased temperatures in the agricultural sector. since agriculture is one of the mos t important economic sectors in the country and is highly affected by temperature changes, this level specifically addresses the impact of temperature on agriculture. results and discussionthe results of the s tudy indicate a clear rise in temperature during the recent period compared to the s tandard climatic period. the average annual temperature, as well as the average minimum and maximum temperatures, show a significant increase during the period 1990-2020 compared to 1961-1990. this temperature rise is particularly noticeable during the warmer months of the year (june and augus t), and the increase in average minimum temperature has been greater than the rise in maximum temperature.in cold and temperate regions, rising temperatures may lead to longer growing seasons for plants. this allows farmers to cultivate crops with longer growing periods and higher yields. the increase in temperature in these regions can also lead to a shift in planting patterns and the possibility of growing heat-tolerant crops, offering new opportunities for farmers.on the other hand, rising temperatures in warmer regions bring threats such as increased evaporation and evapotranspiration, reduced soil mois ture, and increased demand for water resources. these conditions can lead to reduced agricultural productivity and higher irrigation and resource management cos ts. additionally, the temperature rise creates favorable conditions for the multiplication and spread of harmful insects, which can cause serious damage to the agricultural sector. furthermore, increased temperatures can raise cooling cos ts for greenhouses and reduce overall productivity. the results of this s tudy show that the temperature rise in iran in recent periods is clearly evident. this increase in temperature can have both positive and negative effects on various sectors of the country, particularly agriculture. in colder regions, rising temperatures provide opportunities to improve agricultural performance and expand cultivated areas. however, in warmer regions, the temperature increase poses threats such as increased evaporation, greater water demand, and the spread of pes ts and diseases, all of which can lead to decreased agricultural productivity. conclusionto mitigate the negative impacts of these changes, it is essential to adopt appropriate policies in natural resource management and sus tainable agriculture. these policies should include smart water resource management, the use of modern agricultural technologies, and the promotion of renewable energy. additionally, educating farmers to adapt to new conditions and use temperature-resis tant seeds can help improve agricultural performance.in conclusion, this s tudy emphasizes that temperature changes require serious attention and long-term planning to minimize their harm and properly capitalize on the opportunities they present.