Spatial optimization of land use for synergizing economic development and carbon neutrality based on an efficiency-driven PLUS model

Optimizing land-use allocation is important for achieving regional carbon-peaking and carbon-neutrality targets. Existing land-use simulation studies generally incorporate carbon objectives through ex-post assessment or macro-level land-demand optimization, leaving historical grid-level carbon–economic performance disconnected from future spatial allocation. To further address this limitation, we developed LUCE-PLUS, a framework that links grid-scale land-transition accounting and efficiency evaluation with PLUS-based spatial simulation. Using Jiujiang City, China, as a case study, we quantified conversion costs, economic-output changes, and carbon emissions induced by observed land-use transitions from 2010 to 2020 at a 30-m resolution. A single-stage mixed-integer linear programming super-efficiency range-adjusted measure (Sup-RAM) model treated carbon emissions as a weakly disposable undesirable output and enabled discrimination among efficient grid-level transition units while ensuring Pareto-efficient projections. The resulting surfaces of economic efficiency and carbon–economic synergy efficiency were incorporated into PLUS as scenario-specific predictors of land-use expansion probabilities. Land-use patterns in 2030 were simulated under natural-development, economic-dominant, and carbon–economic dual-objective scenarios while aggregate land demand and planning constraints were held constant. Mean carbon–economic synergy efficiency was 20.5% lower than mean economic efficiency, indicating that economic efficiency alone may understate the carbon-related environmental costs of land-use transitions. Compared with the dual-objective scenario, the economic-dominant scenario increased the projected GDP increment by only 0.04% but raised land-use-change-induced carbon emissions by 7.3%. Impervious-land expansion under the dual-objective scenario also showed a stronger tendency toward locations associated with lower carbon-stock losses. LUCE-PLUS therefore provides a performance-informed approach to low-carbon spatial allocation under fixed land-demand targets. From an environmental impact assessment perspective, the framework could support alternatives analysis in strategic environmental assessment of territorial spatial plans by enabling ex ante comparison of projected land-use patterns, carbon-stock changes, and economic outcomes under consistent planning constraints.