the feasibility of underground greenhouses construction as an action to reduce climate change impacts

The greenhouses, as a controlled area, are of special importance for the cultivation of horticultural products, and the use of this sys tem is inevitable in many regions. one of the problems that threaten greenhouse production in recent years in many regions, especially in the colder climates, is the increase in fuel and electricity consumption, and the frequent replacement cos ts of the greenhouse covering. as a result, this s tudy inves tigates the effectiveness of underground greenhouses as a basic method for mitigating and adapting climate change impacts in the arak city climate. to perform this experiment, three greenhouse units were built at 0 meters below the ground level (sg1), 1.5 meters below the ground level (sg2) and 2.5 meters below the ground level (sg3). then, for the cultivation of the crop, each greenhouse was divided into four parts (blocks or duplicates), and the cultivation of scaffolding cucumbers was carried out with a density of two plants per square meter. the growing operation was performed in the same way for all three greenhouses. environmental factors, including temperature, relative humidity, and brightness were recorded at canopy height. the results revealed that the differences in temperature, relative humidity and radiation intensity in all three greenhouses were significant. although, in the underground greenhouses there is more temperature s tability and more relative humidity, the intensity of radiation is less. also, the results of comparing the crop yield in the two seasons showed that the yield difference between sg1 and sg3 greenhouses was significant. however with sg2 greenhouse was not significant. the results showed 5 and 6.5 percent reduction in electricity and gas energy consumption in sg2 greenhouse, respectively. also, results indicated 13.3 and 14.5 percent reduction in electricity and gas energy consumption in sg3 greenhouse, respectively. these figures indicate that 8.3 and 8 percent of electricity and gas energy are saved per depth of underground greenhouses. therefore, using underground greenhouses for agricultural production, will reduce the pressure on the water-food-energy nexus and help in climate change mitigation.