Synergistic Development Mechanism Between Reservoir Resettlers’ Livelihoods and Host Regions

The sustainability of reservoir resettlement depends on the synergistic development of resettlers’ livelihoods and host regions; however, existing studies lack an integrated analytical framework. Combining the Sustainable Livelihoods Framework with synergistic development theory, this study establishes a dual-system evaluation model comprising the Regional Development Support (RDS) and Resettlers’ Livelihood Development (RLD) indices. Using survey data from 289 households across 10 counties in Zhejiang’s QC Reservoir project, we apply composite weighting, coupling coordination modeling, and spatial analysis to evaluate the levels of synergistic development and examine spatial patterns. The findings reveal that (1) there is significant gradient differentiation in the Synergistic Development Index (SDI), with scores ranging from 0.134 to 0.738; (2) spatial autocorrelation is weak (Moran’s I = −0.089), reflecting industrial heterogeneity; and (3) four distinct coordination types are identified, with employment–industry mismatch and ecological constraints being the primary limiting factors. This study provides a diagnostic framework for assessing resettlement outcomes and offers guidance for formulating differentiated policy interventions.