Outdoor ventilation evaluation and optimization based on spatial morphology analysis in Macau

Abstract

Owing to Macau's high urban development intensity, outdoor ventilation is important to enhance human comfort. In this study, four morphological indices as frontal area index (FAI), site coverage (SC), building height (BH) and floor area ratio (FAR) were mapped and analyzed by establishing a refined three-dimensional urban digital model. Then indicator analysis, numerical simulation and LST retrieval were comprehensively used to assess the present outdoor ventilation conditions of Macau. The results showed that Macau's overall spatial morphology was not conducive to ventilation. In hot season, the cool sea breeze was obstructed by high-rise buildings in coastal area of the northern peninsula and difficult to infiltrate into the inner city. In cold season, the high pedestrian level wind speed of urban blocks in coastal areas of southern island was not good for wind protection. In Macau's northern peninsula, three potential wind corridors that connecting several existing open spaces are suggested. In southern island, a clustered urban development mode is proposed to create a wind corridor network. In addition, the existing heat islands in the windward side of wind corridors can be reduced by optimizing land surface. For pedestrian-level ventilation, the wind speed of traditional neighborhoods can be enhanced by reducing site coverage and introducing high-rise buildings during urban renewal. Wind protection methods should be considered in existing coastal urban areas, and low-rise high-density development mode is recommended for coastal new town planning in southern island. This research presents an opportunity to assist urban planners and researchers in developing a comprehensive understanding of Macau's ventilation condition, and provides theoretical support for planning practices for Macau and cities with comparable conditions.