Multi-scenario simulation of land use change and landscape ecological vulnerability analysis in Fuzhou City based on GA-PLUS coupled modeling

The urbanization process has intensified land use changes and ecological pressure, and landscape ecological vulnerability assessment has become a key scientific issue. Taking Fuzhou City as an example, this study constructs a GA-PLUS coupled model based on land use data in 2000, 2010 and 2020, and sets three scenarios of natural development (ND), economic development (ED) and ecological protection (EP) to simulate the spatial pattern of land use in 2030. Unlike traditional approaches that optimize land use areas directly, this study innovatively targets transition probability matrices, enabling more effective scenario differentiation and deeper revelation of policy-driven land conversion mechanisms. The landscape pattern index and landscape vulnerability index were applied to analyze the spatial and temporal evolution characteristics of landscape ecological vulnerability. The results show that: (1) from 2000 to 2020, land use in Fuzhou City has changed significantly, with an increase of 474.68 km2 in construction land and a decrease of 506 km2 in forest land, presenting a spatial pattern of “arable land as the main body, forest land scattered, and construction land clustered”. (2) The simulation of the three scenarios shows that the ED scenario shows the most significant expansion of construction land (change rate of 8.14%), the EP scenario shows the most increase of ecological land, and the ND scenario maintains a relatively balanced development. (3) Landscape pattern changes showed increased fragmentation, but patch cohesion maintained a high level (> 99.95%), and the EP scenario had the highest landscape diversity (SHDI = 0.9164). (4) The landscape ecological vulnerability showed a spatial pattern of “high vulnerability in the southeast and low vulnerability in the northwest”, and the EP scenario could improve the vulnerability situation most effectively, and the area of severely vulnerable area was reduced to 5.70%. The land use change and landscape ecological vulnerability analysis of Fuzhou City were effectively simulated, which provided an important scientific basis for the sustainable development of Fuzhou City.