Impact of urban sunken square design on summer outdoor thermal comfort using machine learning

The issue of the thermal environment in urban open spaces has grown more noticeable due to the combined impact of global warming and the urban heat island effect. Insufficient research has been conducted on the impact of geometric space shape on the thermal environment, despite its significance as a public area. This paper analyses the influence of the geometric space shape of a sunken square on thermal comfort in Chongqing. The evaluation index used is PET, and the methods of field measurement and software simulation are employed. A prediction model is established to examine the relationship between the geometric space shape of the sunken square and thermal comfort. The findings indicate that space view factor (SVF), slope angle, and orientation are the primary determinants influencing the thermal conditions of a submerged square. The SVF and aspect ratio are directly proportional to the pet value of the sunken square, but the slope angle, (width/height) W/H ratio, and depth are inversely proportional to the pet value of the sunken square. Planting a combination of shrubs and grass on the ground is more favorable for enhancing the thermal conditions of the sunken area.