Reconstruction of Indigenous settlements in ecologically fragile areas through spatial distribution patterns and suitability in Xiaoliangshan, SW China.

Indigenous settlements in ecologically fragile mountainous areas are increasingly challenged by fragmented land use, environmental constraints, and cultural marginalization. Using Xiaoliangshan in Southwest China as a case study, this research proposes a spatial optimization framework integrating Suitability evaluation and ant colony-based simulation. The results reveal that high-density settlement zones (> 50 units/km²) concentrate in central plateau basins, contrasting with low-density zones (< 10 units/km²) in steep western regions. Suitability analysis shows high and moderate-high suitability zones, limited to 15.0% of the area, due to ecological and terrain constraints. Model optimization results show that Scenario 7 achieves a utility value of 0.448 by relocating settlements from unsuitable Jinsha River valleys and steep western zones to unified, high-suitability clusters in Xiaoliangshan's 15 township basins (elevation 2000-2600 m, slope < 5°), avoiding ecological reserves and hazards while enhancing infrastructure access and land-use efficiency. Based on these results, a three-tier "Suitability-Ecology-Benefit" synergistic mechanism was proposed, incorporating ecological zoning, tradable ecological quotas guided by shadow pricing, and participatory community planning. The core contribution of this study is to bridge computational optimization and equitable governance by providing a replicable planning tool and a novel method for adaptive planning in socio-ecologically constrained indigenous regions.