Heat Stress Analysis Using the Discomfort Index Method: Impact on Macro Environmental in Yogyakarta

A growing urban development pattern can have both positive and negative impacts. One of them is the thermal discomfort in the form of heat stress. Heat stress is the maximum condition of the human body to receive the heat exposure to various activities. This study analyzed the thermal comfort in Yogyakarta City based on the Discomfort Index (DI) method. The DI method is commonly used in tropical climates using the parameters that include average air temperature and humidity. The data consists of secondary data obtained from Geophysics Station Gamping in 2004-2020 and Climatology Station Mlati in 2017-2020. The result of DI indicated that the highest value occurred in the wet moon climate type in April, with 25.63 °C. Therefore, the conditions showed that more than 50% of people in the city of Yogyakarta fall into an uncomfortable category with an average index of 24.97 °C, which can lead to heat stress. Environmental engineering can be employed to decrease the heat stress potential and improve the thermal comfort for Yogyakarta’s urban community, which is public and private open space, plant road shade vegetation, implement a green façade (vertical garden), as well as improve people’s living behavior and use appropriate clothing.