The impact of the Persian garden principles as traditional ecological landscaping on thermal comfort

Abstract

Outdoor thermal comfort is a key factor generally affecting both physical and mental human health. The increased temperature on days caused by the urban heat island effect is a common phenomenon in cities, which has affected various indicators of quality of urban life such as air quality, use of fossil fuels, human health, etc. Accordingly, to mitigate the heat island effects, the thermal quality of urban open spaces and cooling strategies have been considered by climatologists, urban planners, and landscape designers. In the case of Iran, despite the efforts, studies, and research conducted in this field in recent years, there is no climatic vision at the planning and site design level in most projects. Therefore, it is necessary to emphasize the significance of climatic landscape planning and design and outdoor well-being, not only among urban planners and landscape designers but also among the general public. The Persian garden, known as a traditional ecological landscape in Iran, is the result of valuable experiences of human coexistence with nature and adaptation to climatic conditions during centuries. In fact, the Persian garden not only meets the needs of man and nature but also creates a beautiful environment and provides thermal comfort under the harsh conditions of Iran's hot and dry climate. In this term, the study of the Persian garden, which is based on Iranian culture and believes, is desired and beneficial. Therefore, in this study, after identifying the concept, the structures, and the fundamental elements of the Persian garden and after conceptualizing its ecological design principles, Persian gardens in different climatic zones are selected in order to determine their responses to the changing climatic conditions and their influential factors. Then based on these extracted principles, several scenarios of applying a variety of Persian garden structural elements in the Fin Garden of Kashan, as an outstanding registered world heritage garden, are defined. In order to find the principles of climatic design in the Persian gardens, the ENVI-Met simulations of these scenarios are analyzed on a typical summer day. In the end, the results' efficiency was proved through hypothetical redesign and simulation applied in a similar green space in Kashan with almost equal dimensions. This study concludes that in hot and dry climates, a variety of parameters such as landscape planning, selection and combination of vegetation, water system, geometry, site orientation, surface materials, wind and sunlight control, and spatial arrangement and design influence the outdoor thermal comfort. In conclusion, these results are presented as green strategies and design guidelines for future climate designs in Iran's hot and dry climate.