Sustainability put to the test: environment and regional spatial planning in Chilean public policy (1994–2021)

This article reconstructs and analyzes the evolution of sustainability in regional-scale spatial planning in Chile between 1994 and 2021. It identifies four phases of normative evolution, from the first legal frameworks to the incorporation of Strategic Environmental Assessment (SEA) and recent policies, using a qualitative–quantitative mixed design that combines content analysis of 11 instruments with exploratory visualization through MDS and clustering and inferential testing through PERMANOVA. The findings reveal statistically significant differences across periods and normative hierarchical levels and indicate a paradigm shift from an impact-based approach, centered on Environmental Impact Assessment (EIA), to a strategic framework supported by SEA. This shift coincides with an emergent polycentricity driven by the direct election of regional governors. Nevertheless, challenges remain, including the hegemony of a growth-oriented weak sustainability model, a persistent hierarchical misalignment of environmental concepts, and significant SEA implementation gaps. The study shows that sustainable development, climate change, and SEA act as bridges between environmental and territorial domains. Building on these findings, the research contributes a normative genealogy and a transferable framework for evaluating governance coherence in Latin America. It identifies three priorities: strengthening the hierarchical rank of sustainability principles, mandating SEA as a cross-cutting tool, and enhancing subnational capacities.