Landscape pattern changes and ecological risk assessment of major bays in the Philippines

Abstract

The ecological environment in bay regions is relatively fragile, and the bay regions of Southeast Asia are typical areas of global population growth. Therefore, it is necessary to conduct comparative research on ecological risk assessment in such areas. Five major bays in the Philippines were selected to study the changes in landscape patterns and conduct ecological risk assessments. Land cover information for the five bays in 1990 and 2020 was extracted, and landscape pattern indices were analyzed. Then, the temporal and spatial variations in landscape ecological risk in each bay and the differences from 1990 to 2020 were assessed. The results showed that forestland and farmland are usually associated with stabilization and aggregation, and construction land is expanding, accompanied by the reduction and fragmentation of grasslands and wetlands. There were many medium- and high-risk areas in the Lingayen Gulf, Manila Bay and Bay of San Miguel, which mainly showed changes in wetland, grassland and bare land. The stability of the ecosystem in Macajalar Bay and Davao Gulf is due to the landscape type being mainly forestland. The largest changes across the bays were in grasslands and wetlands, both of which showed varying degrees of elevated fragmentation and separation. Therefore, the development of these bay regions should focus on ecological land such as wetlands and grasslands and treat bare land as the main type of land use while guiding construction land to expand inland and reducing ecological risks along the coast of the bay. This study provides a scientific basis to support the optimization of bay landscape patterns and improve ecologically sustainable development.