تدوین مدل برنامه‌ریزی غیرخطی تخصیص آب و الگوی کشت در شرایط کم‌آبیاری (بررسی موردی: استان‌های تهران و البرز)

نویسندگان

چکیده

با توجه به مصرف چشم‌گیر آب بخش کشاورزی در مقایسه با سایر بخش‌های مصرف‌کننده آب در استان‌های تهران و البرز،‏ تخصیص آب و الگوی کشت محصولات غالب به همراه کم‌آبیاری می‌تواند در مدیریت تقاضای آب نقش اساسی ایفاکند. بدین منظور در این پژوهش،‏ بهینه‌سازی با دو زیرمدل انجام شد که سطح اول،‏ تخصیص درون‌فصلی محصولات و سطح دوم،‏ تخصیص تلفیقی آب و الگوی کشت محصولات در شرایط سال کم‌آبی است. برای تدوین زیرمدل اول،‏ با درنظر گرفتن سطوح مختلف کم‌آبیاری،‏ مقادیر سود خالص تعیین شد و بدین ترتیب رابطه بین سود خالص و آب مصرفی به دست آمد. به‌دلیل رابطه غیرخطی آب‌مصرفی و سود خالص و درنتیجه غیرخطی بودن تابع هدف،‏ از روش برنامه‌ریزی غیرخطی (NLP)‎ استفاده شد. با درنظر گرفتن سناریوهای مختلف در میزان آب دردسترس،‏ مقادیر بهینه سطح زیرکشت و آب اختصاص یافته به هر یک از محصولات تعیین شدند. نتایج حاصل از بهینه‌سازی نشان داد که با تغییر در سطح زیرکشت و استفاده از روش کم‌آبیاری،‏ در بهینه‌ترین حالت،‏ می‌توان سود اقتصادی بخش کشاورزی استان تهران و البرز را 36 درصد در مقایسه با شرایط فعلی بهبود بخشید.

کلیدواژه‌ها


عنوان مقاله [English]

A nonlinear model development of water allocation and cropping pattern in deficit irrigation condition (Case study: Tehran and Alborz Provinces)

نویسندگان [English]

  • Dr M. Bani habib
  • Marziye Hosseinzade
  • Mahmoud Olad Gharehgoz
چکیده [English]

Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.Considering the high water use by agriculture in comparing to the other sectors of Tehran and Alborz Provinces, optimization of cropping pattern and water allocation in deficit irrigation condition can play an important role in water demand management. For this purpose, in the present study, the optimization is performed on the two levels (by two sub-models). The first level was the allocation of intra-seasonal and second level was the integrated optimization of irrigation water allocation and cropping pattern in a dry year condition by second sub-model. The amount of net benefit estimated with regard to the different deficit irrigation and then a benefit function were developed for each crop. In this study, the non-linear programming (NLP) was used due to existing non-linear relationship between net benefit and irrigation water and thus the non-linear objective function is applied. Considering the various scenarios in the amount of available water, optimal cropping pattern and water allocation of individual crops determined. The results of the model indicate that the net benefit of agriculture is improved %36 in Tehran and Alborz Provinces by changing in cropping pattern and using deficit irrigation.

کلیدواژه‌ها [English]

  • Demand water management-Non-linear programming-Optimization-Cropping pattern-Water allocation.-