Abstract The citrus industry is vital to regional economies, and scientific land suitability evaluation is essential for spatial optimisation. This study focuses on Tongcheng County in Hubei Province, which exemplifies a typical red soil hilly region that is ecologically vulnerable in southeastern China. This study integrates Geographic Information System (GIS), Analytic Hierarchy Process (AHP), and fuzzy mathematics to develop a comprehensive land suitability evaluation model that balances factor continuity with evaluation uncertainty. Multi-source spatial data (climate, topography, soil) were used to quantify fuzzy membership functions for citrus growth. Subsequently, we conducted a weighted overlay analysis based on this quantification, which resulted in the creation of a citrus cultivation suitability evaluation map for Tongcheng County. The evaluation results categorised the study area into three distinct zones: (1) The Optimal Zone (CAI ≥ 0.75), which comprises 75.8% (857 km 2 ) of the total study area; (2) The Suitable Zone (0.55 ≤ CAI ≤ 0.75), which constitutes 19.6% (222 km 2 ) of the total study area; and (3) The Unsuitable Zone (CAI ≤ 0.55), which represents 4.6% (52 km 2 ) of the total study area. The research findings aligned with the actual conditions in Tongcheng County, thereby confirming the feasibility of the employed research methodology. These outcomes address research gaps and provide a replicable methodological framework for land evaluation in mountainous regions. This approach can be directly utilised in local agricultural spatial planning and the development of land-use policies. It carries substantial practical implications for advancing sustainable agricultural development and revitalising rural areas in mountainous regions.
Liu et al. (Thu,) studied this question.