Joint Assessment of Ecological Health and Development Pressure for Differentiated Land Use Management in the Guangdong Hong Kong Macao Greater Bay Area

Ecological condition and development pressure describe related but non-interchangeable aspects of land use change. This study assessed the Guangdong Hong Kong Macao Greater Bay Area at 1 km resolution for 2000, 2005, 2010, 2015, 2020, and 2025. The Ecological Health Index (EHI) summarised relative landscape ecological condition from land cover, vegetation, productivity, and landscape configuration. A Dynamic Development Pressure Index based on built-up land and population supported temporal comparison, while a 2025 Integrated Development Pressure Index incorporated nighttime light, roads, and artificial shoreline. Mean EHI changed little, but 24.48% of the common valid area declined locally, while development pressure increased regionally. The 2025 assessment produced six primary screening zones. Within the moderate-EHI class, 90.01% of the area had lower pressure and 9.99% had higher pressure, which were retained as secondary management attributes. Grid results were converted to 651 supported planning units, and a minimum-area coastal rule retained 99.91% of coastal management area. Sensitivity analyses showed that the broad regional pattern was stable under recalibrated weights and modest threshold changes, although rare warning and coastal zones were more sensitive to fixed cutoffs and 2 km aggregation. These findings support the use of the framework for regional screening and differentiated land use prioritisation, while local calibration and field verification remain necessary before statutory application.