Vulnerability Assessment of Rural Human–Land– Industry Systems in the Plateau–Mountain–Basin Ecological Transition Zone: Evidence from 90 Counties in Sichuan, China

The plateau–mountain–basin ecological transition zone of Sichuan Province, China, concentrates national ecological barrier functions and severe rural development pressures along a steep basin–mountain–plateau gradient, and the vulnerability of its rural human–land–industry system constrains green rural revitalization. Existing vulnerability assessments focus on ecosystems or household livelihoods; few take the county as the unit and integrate people, land, and industry into a unified framework. This study constructed a 3×3 matrix framework crossing the three dimensions of exposure, sensitivity, and adaptive capacity with the three system elements of people, land, and industry, selected 16 indicators, and assessed 90 counties of Sichuan. Weights were assigned with the entropy weight method; a vulnerability index was synthesized as VI = EI + SI − AI; counties were classified into five levels with the Jenks natural breaks method; and an obstacle degree model diagnosed the dominant vulnerability-generating factors. Sensitivity carried the largest dimension weight (0.6103), whereas adaptive capacity accounted for only 0.0953, indicating that inadequate capacity is a universal regional deficiency. The mean VI of the 90 counties was 0.2400, rising from the Chengdu Plain (0.1878) through Panxi (0.2704) to Northwest Sichuan (0.2887). Of the 22 high-vulnerability counties, 15 lay in Northwest Sichuan, 6 in Panxi, and only one, Guanghan City, on the plain. The leading obstacle factors were the proportion of ethnic minority population (16.52%) and county-seat altitude (9.93%), and three vulnerability types were identified: alpine ecological–ethnic compound, mountain poverty–sensitivity compound, and plain high-density sensitivity. Re-weighting with the coefficient-of-variation method yielded a Spearman rank correlation of 0.9041, confirming robustness. The framework supports county-specific adaptation strategies for green rural revitalization in ecological transition zones.