مکان یابی زمین ‌های دیم مستعد آبیاری تکمیلی به منظور ارتقای بهره وری مصرف آب

ارتقای بهره‌وری مصرف آب کشاورزی  یکی از راهکارهای به‌زراعی مهم برای رسیدن به کشاورزی پایدار محسوب ‌می‌شود. در این راستا، مکان‌یابی زمین های دیم مناسب به‌منظور اجرای آبیاری تکمیلی از اقداماتی است که برای بهبود بهره‌وری مصرف آب و امنیت غذایی مورد توجه محققان قرار گرفته است. در این پژوهش، با استفاده از روش تصمیم‌گیری تحلیل سلسله ‌مراتبی (ahp) زمین های دیم مستعد آبیاری تکمیلی در استان زنجان تعیین شد. برای این منظور، معیارهای دسترسی به منابع آب، کیفیت آب، ویژگی های کمی و کیفی خاک، اقلیم، راه دسترسی و توپوگرافی در نظر گرفته شد. مقایسه های زوجی بین معیارها و طبقه‌بندی زمین ها با استفاده از نقشه‌های پهنه‌بندی تهیه شده در محیط arcgis اجرا و نشان داده شد که بیشترین وزن و اهمیت را معیار دسترسی به منابع آب و کمترین وزن را معیارهای جاده دسترسی و توپوگرافی داراست. بر اساس نقشه‌های مکان‌یابی تهیه شده و انطباق آن با نقشۀ زمین های دیم استان زنجان، کلاس زمین های دیم از نظر قابلیت اجرای آبیاری تکمیلی شامل 19 درصد کاملاً مناسب، 40/6 درصد مناسب، 27/8 درصد با محدودیت متوسط، 10/6 درصد نامناسب و 2 درصد کاملاً نامناسب شناخته شد.

locating suitable rainfed land for supplemental irrigation to improve water productivity

population pressures continue to undermine effective land and water management in many developing countries. improving water productivity in agricultural lands is essential for enhancing production and adapting to the water scarcity crisis. rainfed lands play a crucial role in food production. breeding and crop improvement are two important strategies for increasing water productivity. supplemental irrigation is considered one of the crop improvement managements in rainfed lands. this management approach involves providing one or two irrigations during critical growth periods, which can significantly improve yield and water productivity on rainfed lands. however, the effectiveness of supplemental irrigation depends on accessibility to water resources, water quality, soil fertility, and other important factors. therefore, locating suitable rainfed areas for implementing supplemental irrigation will be the first step. the area under cultivation of rainfed lands in zanjan province is substantial, covering 338,000 ha. it is recognized as one of the provinces with a high capacity for producing rainfed crops in the country. this paper presents a comparative analysis of the analytic hierarchy process (ahp) in the context of decision-making for supplemental irrigation site selection using geographic information systems (gis) in zanjan province. for this purpose, several criteria were employed in the selection process, based on the literature concerning factors that influence supplementary irrigation performance. methodologyin this research, zanjan province was selected as the study area. the criteria examined in this research encompass the accessibility of water resources, water quality, soil properties, climatic factors, topography, and road accessibility, including its sub-criteria. the ahp method was employed to prioritize rainfed lands for supplemental irrigation. the ahp process consists of three key components: identifying a hierarchy of objectives, criteria and alternatives; conducting pairwise comparisons of the criteria; and integrating the results from these comparisons to determine the relative importance across all levels of the hierarchy. the factors influencing site selection exhibit various characteristics; some are descriptive and can vary in quantity, while others possess numerical values. consequently, it is essential to standardize the values and weights of each factor. zoning maps for each sub-criterion were prepared as information layers using arcgis software, and subsequently, all prepared maps were re-scored through a reclassification process. the pairwise comparison tables for the ahp method were generated using the extahp plugin in arcgis software, establishing the weight coefficients for the criteria. the land classification map was created by overlaying the zoning maps corresponding to each criterion while considering the assigned weights. finally, by integrating the obtained map with the rainfed land map of zanjan province, suitable rainfed fields for supplementary irrigation were determined. results and discussionthere are generally no significant restrictions in most areas of zanjan province regarding the water quality, soil properties, climatic factors, road accessibility, and topography for implementing supplemental irrigation. however, in certain regions, limited accessibility to water resources has caused restrictions.