Which green is more equitable? A study of urban green space equity based on morphological spatial patterns

Urban green space (UGS) is an important factor in sustainable urban development. However, cities often experience unequal access to UGSs during the process of development, due to factors such as shrinkage and spreading. Many cities worldwide are facing urban shrinkage, which may lead to the deterioration of urban spatial environments and aggravation of inequities. In addition, due to urban land and financial constraints, it is not possible to maintain UGS equity by simply increasing the number of UGSs. Therefore, it is necessary to explore what defines a reasonable UGS structure from an equity perspective to support sustainable urban development. In this study, the UGS equity index of Yokosuka City was measured using the Gini coefficient. Morphological spatial pattern analysis (MSPA) was used to understand the morphological structure of UGSs in different regions and to transform them into potential structural classes. Finally, a UGS equity prediction model was constructed by ridge regression to provide a UGS morphological structure that is conducive to equitable UGS development. The main results indicate that 1) UGS inequity exists in Yokosuka; 2) no relationship was found between population decline and UGS inequity in Yokosuka; 3) UGS distribution is more equitable in towns with higher land values and population aging; 4) Islet, edge, loop, and branch components play an important role in the equitable development of UGS, and their corresponding potential UGS morphology is fragmentation, complexity, internal connectivity, and partial connectivity, respectively. This study further improves the analytical framework for describing the morphological structure of UGSs based on MSPA from a morphological perspective and provides a spatial morphological strategy to support the equitable development of UGSs.