نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 استادیار پژوهشکده کشاورزی- پژوهشگاه زابل- زابل- ایران
2 دانشیار دانشکده مدیریت و اقتصاد- دانشگاه سیستان و بلوچستان- زاهدان- ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objective: Water is a critical input for agricultural production and plays an important role in the sustainable development of the agricultural sector and the economic development of other sectors. Water shortage is one of the major challenges that most countries in the world are struggling with. The great importance of determining the optimal cropping pattern of crops and irrigation allocation planning in the water shortage conditions prevailing in Iran's watersheds is not hidden from anyone. This study aimed to optimize water allocation and determine the optimal cropping pattern of crops in five cities of the Sistan region under different management scenarios.
Materials and methods: In this study, a model with a two-level planning approach, the Stackelberg game framework, and a genetic algorithm, was developed to optimize the water allocation between irrigated areas and crops, as well as to determine the optimal cropping area in 5 cities of Sistan region (including Hamon, Hirmand, Zahak, Nimroz and Zabol) to confront different water conditions. Selected products include wheat, barley, onion, melon, watermelon and alfalfa. The problem was solved in the form of nine scenarios, including three scenarios of irrigation efficiency, three scenarios of climatic conditions, and three scenarios of low irrigation conditions, and compared with the baseline scenario.
Results: For water allocation among the studied regions in the baseline scenario, the most and least water was allocated to Zahak and Hirmand areas, respectively. Among the studied crops, the most water was allocated to the melon due to its low water requirement and high economic value compared to other crops, and the least amount of water was allocated to the alfalfa due to its high water requirement; also the melon with 13503.5 ha had the highest cropping area and alfalfa with 4.85 ha had the lowest cropping area in a total of five cities. The total cropping area obtained by the model was 18240.32 ha. The value of the Gini coefficient was 0.0053, which is small and close to zero, indicating that the water allocation between the regions was fair. The total interest rate obtained in the baseline scenario was 5.06 ×1013, which by applying irrigation efficiency scenarios of 50 and 70 percent, the amount of profit has increased by 12% and 34%, respectively, and the cultivated area by 27% and 47% compared to the baseline scenario. And in normal and wetyear conditions, the amount of total profit has increased by 28% and 54%, respectively, and the cultivated area by 40% and 65% compared to the baseline scenario. By applying the low irrigation scenario, the interest rate decreases compared to the baseline scenario, associated with the saving of a large volume of irrigation water, which leads to an increase in the cropping area of crops with higher economic efficiency. Therefore, by applying various scenarios, the cropping pattern moves towards crops with less water requirement and higher economic value.
Conclusion: According to the results, more water has been allocated to crops with higher economic value and less water requirement. Therefore, if crops with less interest rate compared to their water use and crops with high water requirement are removed from the cropping pattern and crops with higher economic efficiency and less water requirement are replaced in the cropping pattern, it can be a good solution to confront water shortage conditions. The increase in irrigation efficiency increased the total interest, thus it is recommended to save water used by plants through the improvement of irrigation technology and increase irrigation efficiency. The proposed model in this study can be employed for correct and efficient planning for agriculture and water resource management in various conditions.
کلیدواژهها [English]
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