Evolutionary Trajectories and Adaptive Transformation of Cold-Region Rural Human Settlements from a Social–Ecological Systems Perspective: Evidence from Heilongjiang, China

From a social–ecological systems perspective, cold-region rural human settlements are human-centered spatial settings adapting to population shrinkage, declining density, and prolonged cold; existing assessments often compress change into single-period scores or endpoints and mix pressures with settlement states, obscuring evolutionary pathways and transformation needs. This study examines 13 prefecture-level units in Heilongjiang, China, from 2014 to 2024 by measuring settlement state, identifying multidimensional trajectories, interpreting their pressure contexts, and deriving differentiated transformation modes. Fifteen indicators measure livelihoods and production, social equity and public services, ecological conditions, and governance response; population shrinkage, density decline, and compound cold exposure are analyzed as structural pressure contexts. Fixed-boundary normalization, Theil–Sen trend estimation, dimensional imbalance measurement, and Ward clustering are combined to identify system trajectories. The settlement state index increased from 0.301 to 0.529 (Δ = 0.229), and all 13 units ended above their 2014 levels. However, improvement was asynchronous: after fluctuating gains, the ecological dimension returned to slightly below its baseline, indicating that ecological improvement had not been consolidated. Three pathways were identified: low-level catch-up with widening imbalance, medium-level steady improvement with structural lock-in, and high-level acceleration with convergence under pressure. They correspond, respectively, to livelihood–governance reinforcement and service network adaptation, governance upgrading with ecological–livelihood coordination, and resilience consolidation under ecological constraints. Within the complete Heilongjiang prefecture system, linking measured state pathways to pressure contexts and transformation priorities provides a transparent basis for shifting cold-region rural governance from uniform expansion toward differentiated optimization of existing assets and services, while wider transfer requires indicator recalibration and multiscale outcome validation.