پديد آورندگان :
كوزه گران، سعيده دانشگاه فردوسي مشهد - دانشكده كشاورزي - گروه مهندسي آب , موسوي بايگي، محمد دانشگاه فردوسي مشهد - دانشكده كشاورزي - گروه مهندسي آب , خاشعي سيوكي، عباس دانشگاه بيرجند - دانشكده كشاورزي - گروه مهندسي آب , باباييان، ايمان پژوهشكده اقليم شناسي مشهد
كليدواژه :
شاخص هاي بارش , شاخص هاي دما , رويدادهاي حدي اقليمي , عملكرد
چكيده فارسي :
آب و هوا، هم به لحاظ ميانگين ها و هم رويدادهاي حدي از جمله عوامل مهم تأثيرگذار بر عملكرد محصولات ميباشد. رويدادهاي حدي آب و هوايي، در حال حاضر يك چالش مهم براي توليدكنندگان محصولات كشاورزي ميباشد كه در حال افزايش است و پيش بيني و محاسبه اثرات آنها بر عملكرد محصولات از مهمترين موضوعات مورد بررسي در بحث امنيت غذايي، جهت افزايش كارايي اقتصادي توليدات ميباشد. بررسي روند چند سال گذشته زعفران نشان ميدهد، در حاليكه سطح زير كشت زعفران در ايران افزايش داشته، ميزان عملكرد در واحد سطح كاهش داشته است. با توجه به اهميت زعفران و اينكه عملكرد آن به طور قابل توجهي تحت تأثير شاخص هاي اقليمي ميباشد، بررسي و شناخت الگوي رويدادهاي حدي و تأثيرگذاري آن بر عملكرد مي‌تواند به برنامه ريزي هاي مديريتي و بهره برداري بهتر اين محصول كمك نمايد. در اين مطالعه جهت بررسي روند نمايه هاي حدي اقليمي، از 38 شاخص بارش و دما كه توسط تيم كارشناسي شكارسازي تغييرات اقليمي سازمان جهاني هواشناسي به عنوان شاخص هاي حدي و تغييرات آب و هوايي، استفاده گرديد. سپس با استفاده از آناليز رگرسيون چند متغيره، اثر شاخص هاي حدي اقليمي بر عملكرد بررسي و با انتخاب مناسبترين شاخص ها، مدل عملكرد بر اساس شاخص ها ارائه شد. نتايج تجزيه و تحليل شاخص ها، روند گرم شدن منطقه و كاهش بارش را نشان مي هد. اين نتايج نشان داد كه روند افزايشي شاخص هاي حدي گرم و روند كاهشي و منفي شاخص هاي بارش ميتوانند از عوامل مهم و عمده در كاهش عملكرد زعفران باشند.
چكيده لاتين :
Weather, whether in terms of averages or events, is an important determinant of yields. Extreme weather events, already a significant challenge for crop producers, are predicted to increase under future. Extreme weather events are expected to increase worldwide, therefore, anticipating and calculating their effects on crop yields is important for topics ranging from food security to the economic viability of products. During recent years, monitoring of saffron has revealed that in spite of increase in Iranian cultivated areas in Iran. Its yield per unit area has decreased. Due to its importance and determinant that it is highly dependent on meteorological events, recognition and evaluation of extreme events and their influences on saffron yield can lead to a better utilization and management planning. To evaluate the extreme climate indices trend (during 1991-2015), 38 indices of rainfall and temperature that defined by the CCl/CLIVAR/JCOMM team were used. Afterward, using the stepwise regression analysis, the effects of weather extreme events were evaluated. Then, by selecting the best indices, saffron yield model was proposed. Analysis of indices demonstrate the trends of region warming and precipitation decrement. From the results of this study, it could be concluded that the incremental trend of warming extreme indices coupled with the negative trend of precipitation are the most significant factors in decrease of saffron yield. Weather, whether in terms of averages or events, is an important determinant of yields. Extreme weather events, already a significant challenge for grain producers, are predicted to increase under future. Extreme weather events are expected to increase worldwide, therefore, anticipating and calculating their effects on crop yields is important for topics ranging from food security to the economic viability of products. During recent years, monitoring of saffron has revealed that in spite of increase in cultivated areas of saffron in Iran, its yield per unite area has decreased. Due to saffron significance in this region and the fact that determinant of saffron is highly dependent on meteorological events, recognition and evaluation of extreme events and their influences on saffron yield can lead to a better utilization and management planning. To evaluate the extreme climate indices trend (1991-2015), 38 indices of rainfall and temperature, defined by the CCl/CLIVAR/JCOMM team are used. Afterward, using the stepwise regression analysis, the effects of weather extreme events are evaluated. Then, by selecting the best indices, saffron yield model is proposed. Indices analysis demonstrates, the trends of region warming and precipitation decrement. From the results of this study, it can be concluded that the incremental trend of warming extreme indices coupled with the negative trend of precipitation are the most significant factors in decrease of saffron yield.
