Spatial Injustice in Construction Land Reduction: Measurement and Decomposition

Spatial justice requires equitable construction land allocation to realize disadvantaged regions’ development rights. Construction land reduction (CLR) in economically developed areas is a complex and multi-dimensional process of land spatial optimization. While optimizing the allocation of land resources, this process may also lead to challenges in spatial justice. This study assessed spatial injustice using construction land data from W-district, Shanghai, based on spatial simulation. Planning documents indicated that some areas had a net resident outflow; the simulation showed that promoting CLR decreased mixed land use in these areas. Control of construction land decreased industrial and mining storage and rural residential land; urban residential, commercial, and other construction land increased. Bottom-line planning thinking reduced spatial injustice by approximately 0.0393 overall (the reduction rate was nearly 14.05%). Under territorial spatial planning, construction land stock quotas were optimized; CLR quotas were transferred, creating significant differences in construction land internal structures. Weighted Gini coefficients suggested unfair distribution between urban residential and commercial land, with the latter being more concentrated. Industrial and mining storage, other construction, and urban residential land contribute to spatial injustice. Industrial and mining storage and urban residential land have positive marginal effects; those of commercial, rural residential, and other construction land are negative. Promoting centralized residences has consolidated scattered rural residential land; decreasing rural residential land inhibits spatial injustice reduction. Construction land and the population can be agglomerated simultaneously to reduce construction land inequality.