Multi-scenario land use prediction and layout optimization in Nanjing Metropolitan Area based on the PLUS model

The metropolitan area is a crucial spatial element in promoting new urbanization in China.It possesses theoretical and empirical value in the determination of the evolutionary patterns and development trends necessary for regional integration and high-quality development.This study focused on Nanjing Metropolitan Area,the first national metropolitan area in China,and established three development scenarios by combining ecological–economic spatial conflict(EESC)zones and national key ecological functional areas.These scenarios simulate the spatial distribution of future land use and land cover change(LUCC)using the development zone planning function of the patch generation land use simulation(PLUS)model.The results show that:(1)Between 2000 and 2020,the most prominent characteristics of land use change were largely the massive expansion of built-up land and the significant decline of farmland,while changes in the area of ecological land were less evident.(2)EESC areas experienced significant changes over the past 20 years,but the overall level of conflict was low.Ecological land was the main land use type in the lowest-conflict area,while built-up land was the main land use type in the highest-conflict area.(3)From 2030 to 2050,further expansion of built-up areas is expected,with continued decrease of farmland.The regulation of these land use changes can be achieved through different development zone plans.The economic development scenario had the largest built-up land area,while the ecological protection scenario had the largest farmland area.This study simulates the spatial pattern changes in the metropolitan area based on spatial conflict patterns and national main functional area planning process,providing a scientific reference for future spatial planning and management.