Morphology changes and the expansion of major port cities in the Philippines from 1990 to 2020.

Research concerning urban expansion has been conducted worldwide in the context of global urbanization, yet comprehensive and systematic research on urban growth and morphological changes in Asia is lacking. In this study, the land use, population, and economic development of nine major port cities in the Philippines from 1990 to 2020 were analyzed. The urban land density inverse S function was used to conduct an in-depth analysis of changes in urban spatial morphology. The urban growth patterns were studied by landscape expansion indexes were studied. The results showed that the land area of nine port cities increased by 246.7 km2. Infill expansion in Metro Manila, Cebu, and Bacolod accounted for >60 % of the newly added urban land and has led to a more compact urban form; edge and outlying expansion in General Santos, Batangas, Cagayan de Oro, and Iloilo accounted for >80 % and has led to dynamic changes involving compactness and dispersion. Urban boundaries and terrain limit the development of slow and medium-speed expansion cities; the combination with surrounding cities into megacities can be considered in the future. In contrast, rapidly expanding cities need to improve their compactness and efficiency of urban land use. • This paper provides comprehensive research on urban growth and morphological changes in nine cities in the Philippines. • Infill expansion led to a more compact urban form. • Edge and outlying area expansion form is undergoing dynamic changes involving compactness and dispersion. • The combination of metropolitan with surrounding cities can be considered for slow and medium-speed expansion cities. • Rapidly expanding cities need to improve their compactness and efficiency of urban land use. [ABSTRACT FROM AUTHOR]