تحلیل پتانسیل مناطق ایران برای کشت گلخانه‌ای گوجه‌فرنگی با تأکید بر نیازهای گرمائی و سرمائی از طریق سامانه اطلاعات جغرافیایی

Greenhouse cultivation has emerged as a strategic response to the growing challenges posed by population growth, urban expansion, resource limitations, and the increasing demand for off-season crops. In recent decades, rapid socio-economic transformations in developing countries such as Iran have intensified the need for sustainable agricultural methods that optimize resource consumption, particularly water and energy. Traditional open-field farming faces numerous limitations due to climate variability, land degradation, and dwindling groundwater resources, prompting a significant shift toward protected cultivation systems. Among these, greenhouse agriculture offers the advantages of higher crop yield, better control over growing conditions, and enhanced resource use efficiency. However, the feasibility and sustainability of greenhouse farming largely depend on local climate characteristics—specifically heating and cooling requirements, which directly influence energy consumption patterns. In order to maximize efficiency and minimize operational costs, it is essential to identify optimal locations for greenhouse development based on precise climatic criteria. Geographic Information Systems (GIS), when combined with meteorological data, provide powerful tools for spatial analysis and environmental suitability assessment. This study leverages GIS to evaluate the heating and cooling degree-day needs for greenhouse tomato cultivation across Iran, ultimately identifying regions with the lowest thermal energy requirements and offering practical insights for optimizing greenhouse location strategies.
Introduction
The increasing demand for food due to population growth, along with rapid economic and cultural development, has intensified the expansion of greenhouse cultivation worldwide. In Iran, several challenges such as water scarcity, declining groundwater levels, limited arable land, and the growing need to produce crops off-season have further emphasized the importance of greenhouse farming. Greenhouse cultivation offers numerous advantages, including enhanced crop yields, efficient water use, and reduced dependency on external environmental conditions. However, the optimal performance of greenhouses is highly dependent on local climatic factors, particularly thermal requirements. Heating and cooling demands vary significantly across different geographic regions, directly affecting energy consumption and economic feasibility. Therefore, identifying suitable locations for greenhouse construction based on thermal efficiency is essential. This study addresses the need to evaluate Iran’s diverse climate zones to determine the most appropriate areas for greenhouse tomato cultivation from the perspective of heating and cooling degree-day requirements using Geographic Information Systems (GIS).
Materials and Methods
To assess the suitability of different regions in Iran for greenhouse tomato production, a spatial analysis was conducted using GIS tools. Climatic data, including temperature records from synoptic weather stations across the country, were collected and processed to calculate heating and cooling degree-days (HDD and CDD) for each region. Degree-day indices were computed based on standard temperature thresholds associated with the growth requirements of greenhouse tomatoes. Thermal maps for both HDD and CDD were then generated to illustrate spatial variability across Iran. These maps served as the primary basis for identifying regions with minimum heating or cooling needs. The zoning was performed using interpolation methods, and final suitability maps were derived by integrating the thermal layers with geographic and climatic constraints relevant to greenhouse construction.
Results and Discussion
The results revealed significant spatial variation in thermal requirements for greenhouse tomato production across Iran. The heating demand ranged from 0 to 3500 degree-days annually, with the highest requirements observed in colder regions such as Firouzkouh in the north. Conversely, cooling needs varied from 0 to 2500 degree-days, with the highest values recorded in warmer areas like Shushtar in the southwest. Based on the thermal zoning maps, southern regions of Iran—particularly in the southern, southwestern, and southeastern parts—were identified as optimal locations for winter-season greenhouse tomato cultivation due to their minimal heating needs. These areas offer substantial energy-saving potential during colder months. In contrast, northern, northwestern, and northeastern parts of the country exhibited the lowest cooling requirements, making them suitable for summer-season greenhouse tomato production. The spatial distribution of thermal demand aligns well with energy-efficiency goals and can support a seasonal strategy to minimize input costs while maximizing productivity. Furthermore, the analysis highlights the significance of location-specific planning in greenhouse agriculture, emphasizing that thermal suitability should be a primary factor in site selection.
Conclusion
This study demonstrates the value of GIS-based spatial analysis for identifying thermally suitable regions for greenhouse tomato cultivation in Iran. By mapping heating and cooling degree-days, the research provides a comprehensive overview of climate-based suitability across the country. The findings suggest that optimizing the location of greenhouse structures according to seasonal thermal needs can significantly reduce energy consumption and improve economic efficiency. Southern Iran is best suited for off-season production during cooler months, while northern regions are favorable for warm-season cultivation. Integrating such climatic assessments into greenhouse development strategies can contribute to more sustainable and resilient agricultural systems in arid and semi-arid regions. Future studies may expand on this framework by incorporating additional factors such as solar radiation, humidity, and economic cost-benefit analyses to further refine location recommendations for greenhouse farming.
Introduction
The increasing demand for food due to population growth, along with rapid economic and cultural development, has intensified the expansion of greenhouse cultivation worldwide. In Iran, several challenges such as water scarcity, declining groundwater levels, limited arable land, and the growing need to produce crops off-season have further emphasized the importance of greenhouse farming. Greenhouse cultivation offers numerous advantages, including enhanced crop yields, efficient water use, and reduced dependency on external environmental conditions. However, the optimal performance of greenhouses is highly dependent on local climatic factors, particularly thermal requirements. Heating and cooling demands vary significantly across different geographic regions, directly affecting energy consumption and economic feasibility. Therefore, identifying suitable locations for greenhouse construction based on thermal efficiency is essential. This study addresses the need to evaluate Iran’s diverse climate zones to determine the most appropriate areas for greenhouse tomato cultivation from the perspective of heating and cooling degree-day requirements using Geographic Information Systems (GIS).
Materials and Methods
To assess the suitability of different regions in Iran for greenhouse tomato production, a spatial analysis was conducted using GIS tools. Climatic data, including temperature records from synoptic weather stations across the country, were collected and processed to calculate heating and cooling degree-days (HDD and CDD) for each region. Degree-day indices were computed based on standard temperature thresholds associated with the growth requirements of greenhouse tomatoes. Thermal maps for both HDD and CDD were then generated to illustrate spatial variability across Iran. These maps served as the primary basis for identifying regions with minimum heating or cooling needs. The zoning was performed using interpolation methods, and final suitability maps were derived by integrating the thermal layers with geographic and climatic constraints relevant to greenhouse construction.
Results and Discussion
The results revealed significant spatial variation in thermal requirements for greenhouse tomato production across Iran. The heating demand ranged from 0 to 3500 degree-days annually, with the highest requirements observed in colder regions such as Firouzkouh in the north. Conversely, cooling needs varied from 0 to 2500 degree-days, with the highest values recorded in warmer areas like Shushtar in the southwest. Based on the thermal zoning maps, southern regions of Iran—particularly in the southern, southwestern, and southeastern parts—were identified as optimal locations for winter-season greenhouse tomato cultivation due to their minimal heating needs. These areas offer substantial energy-saving potential during colder months. In contrast, northern, northwestern, and northeastern parts of the country exhibited the lowest cooling requirements, making them suitable for summer-season greenhouse tomato production. The spatial distribution of thermal demand aligns well with energy-efficiency goals and can support a seasonal strategy to minimize input costs while maximizing productivity. Furthermore, the analysis highlights the significance of location-specific planning in greenhouse agriculture, emphasizing that thermal suitability should be a primary factor in site selection.
Conclusion
This study demonstrates the value of GIS-based spatial analysis for identifying thermally suitable regions for greenhouse tomato cultivation in Iran. By mapping heating and cooling degree-days, the research provides a comprehensive overview of climate-based suitability across the country. The findings suggest that optimizing the location of greenhouse structures according to seasonal thermal needs can significantly reduce energy consumption and improve economic efficiency. Southern Iran is best suited for off-season production during cooler months, while northern regions are favorable for warm-season cultivation. Integrating such climatic assessments into greenhouse development strategies can contribute to more sustainable and resilient agricultural systems in arid and semi-arid regions. Future studies may expand on this framework by incorporating additional factors such as solar radiation, humidity, and economic cost-benefit analyses to further refine location recommendations for greenhouse farming.