پهنه‌بندی اقلیمی پتانسیل کشت گندم ( (triticum aestivum l.استان گلستان

در کشاورزی، پیدا کردن مکان بهینه برای محصولات کشاورزی می‌تواند مزایای اقتصادی را افزایش و پیامد‌های منفی زیست‌محیطی را کاهش می‌دهد. به‌منظور ارزیابی اقلیمی اراضی کشاورزی استان گلستان برای کشت گندم ((triticum aestivum l.، از سامانه اطلاعات جغرافیایی (gis) و روش خطی وزنی (wlc) استفاده شد. بدین منظور ابتدا نیاز‌های زراعی و متغیر‌های محیطی تعیین، درجه‌بندی و مطابق با آن‌ها نقشه‌های موردنیاز تهیه گردید. متغیرهای اقلیمی موردمطالعه شامل: حداکثر دما، حداقل دما، دمای متوسط و بارندگی در مرحله کاشت و در طی دوره‌ رشد بودند. در این پژوهش از آمارهای 10 سال اخیر پارامتر‌های اقلیمی 25 ایستگاه هواشناسی استان گلستان استفاده گردید. برای استانداردسازی داده‌ها از روش فازی و برای وزن دهی به معیارها از روش تحلیل سلسله مراتبی (ahp) استفاده‌شده است. در نهایت، با استفاده از روش ترکیب خطی وزنی (wlc) در محیط نرم‌افزار idrisi، نقشه‌ پتانسیل‌ کشت گندم دیم تهیه گردید. نتایج نشان داد که در وزن دهی معیارها با روش تحلیل سلسله مراتبی، مقدار بارندگی در دوره رشد با 3407/0 درصد بیشترین و حداقل دمای دوره سبز شدن با 0306/0 درصد کمترین ضریب‌ها را کسب کردند. در نقشه‌ برونداد حاصل از روش ترکیبی خطی وزنی ازلحاظ عوامل اقلیمی نشان داد که بیش از 55 درصد اراضی جهت کشت گندم در پهنه بسیار مستعد و مستعد قرار دارند که این اراضی بیشتر در شمال شرقی و مرکز استان واقع‌شده‌اند که می‌توان علت آن را مقدار بارش کافی و دمای مناسب بیان نمود. علاوه بر این، عامل محدود‌کننده کشت گندم از لحاظ اقلیمی در استان گلستان را می‌توان مقدار بارش در طول فصل رشد را ذکر نمود.

Potential Climatic Zoning of Wheat (Triticum aestivum L.) Golestan Province

IntroductionCrop selection based on land capabilities has been used in several studies to assess the suitability of land for specific crops in order to determine the optimal cropping system. Maize, rice, wheat, barley, cotton, soybean and canola are the major crops found in the agricultural production systems of Golestan province, Iran. Soybean (Glycine max L.; Fabaceae) is grown worldwide as an important staple and commercial crop. Kamkar et al., (2014) on assessment review of land suitability for cultivation of rapeseed and soybean in four basins over Golestan province, using GIS reported that only 11.82% of the total lands very suitable to rotate soybean after canola, used raster layers for them study were included climatic (precipitation, temperature), topographic (aspects and slope) and soilrelated (texture, pH, EC). The Geographical Information System (GIS) offers a flexible and powerful tool as it can combine large volumes of different kinds of data into new datasets and display these new datasets in the form of informative and accessible thematic maps. The aim of this study was to perform land suitability assessments for wheat cultivation Golestan province, and to investigate the possibility of wheat cultivation. In this way, we used GIS and a comprehensive data set on wheat crop ecological requirements, agro climatological, topographic and soil data.Material and MethodsGeographical Location of the Region The province of Golestan with an area of 21,500 square kilometers, is in the southeast of the Caspian Sea. This area extends from 36_440 N to 38_50 N and from 51_530 E to 56_140 E. In general, Golestan has a moderate and humid climate known as "the moderate Caspian climate. arid and semiarid areas has occupied more than 35% of Golestan province. The study area of the research, include agricultural lands and rangelands of Golestan province is present. Using 1: 50,000 maps of the national cartographic center of Iran, we created a 20 m digital elevation model (DEM) with a topotoraster function. Method of studyIn this study, the first agroecological requirements and of wheat were determined based on scientific resources. Studied climatic variables were included average, minimum and maximum temperatures, precipitation in the date planting and during growth season of crop. Data of the last 10 years were collected and recorded from 25 stations located within the study area. The standardization of data was used from fuzzy method and Analytic Hierarchy Process (AHP) was used for weighting the criteria. Finally, using weighted linear combination (WLC) in the software IDRISI, wheat cultivation potential map was prepared.Results and DiscussionThe results showed that the weighted criteria of AHP, the amount of precipitation during the growing season had the highest amount with 0.3407 and minimum temperature in the emergence stage with 0.0306 had the lowest coefficient in the rankings. The digital environmental layers overlaid and integration in GIS media then zoning of lands carried out in 4 classes (high suitable, suitable, less suitable and unsuitable). The results showed that 9.54% and 54.53% of this area were high suitable and suitable for wheat cropping, respectively. ConclusionIn the output map from weighted linear combination, the located lands in East, Southeastern, South and Southwest had the lowest potential production for wheat. These areas were consisted of steep slopes, highest elevation, less precipitation and less favorable area in terms of areas which had unfavorable climate areas and other areas that located in the Northeastern, center and Northwest of the province had the best potential for wheat production which can be said cause of sufficient amount precipitation, low slope and elevation, favorable soil and temperature.