Evaluation of riverine wetlands ecosystem health based on ecological integrity: a case study of riverine wetlands in the southern section of Gaoligong Mountain, Yunnan Province, China

Riverine wetlands underpin regional socio-economic development by sustaining critical ecosystem functions and services, including water provision and regulation, ecosystem maintenance, and biodiversity conservation. Accordingly, a rigorous assessment of riverine wetland ecosystem health is essential for guiding rational water-resource utilization and supporting sustainable regional development. Anchored in the concept of ecological integrity, this study developed an integrated framework for evaluating riverine wetland health through the systematic classification, reorganization, and synthesis of widely used river-health indicators into a coherent, multi-dimensional index system. The framework comprises three complementary indicator domains, aquatic biological, physical (habitat), and chemical (water-quality) indicators, designed to capture biological community condition, habitat structure and stability, and the physicochemical environment, respectively. To ensure that the relative diagnostic value of these domains was explicitly represented in the assessment, the Analytic Hierarchy Process (AHP) was used to derive criterion-level weights. The weighting scheme assigned the highest importance to aquatic biological indicators, followed by physical indicators, with chemical indicators weighted lowest, reflecting the premise that biotic assemblages and habitat attributes often integrate cumulative environmental effects and could be more responsive to disturbance than routine chemistry at reach-to-river scales. Because the differential importance of individual metrics within each domain is difficult to determine objectively, equal weights were assigned to metrics within the same domain. The finalized framework includes 18 metrics, encompassing attributes of benthic macroinvertebrate communities, channel morphology and riparian condition, and key water-quality variables (e.g., nutrients and dissolved oxygen). Metric scores were standardized and aggregated to generate an integrated health index, which classified riverine wetland condition into five grades ranging from ‘very poor’ to ‘healthy’. The framework was applied to riverine wetlands in the southern section of the Gaoligong Mountains, Yunnan Province, China. Field investigations were conducted in November 2018, integrating assessments of channel form and riparian habitat, measurements of water physicochemical properties, and standardized collection and identification of benthic macroinvertebrates. Application of the integrated index indicated that the study area could be partitioned into two major basins, the Dulong River Basin and the Nu River Basin, both of which were evaluated as healthy at the basin scale. At the river scale, five of the six investigated rivers were classified as healthy, whereas one river was rated good. Relative to previous assessments conducted in the same region, the restructured and reweighted framework yielded results judged to be more reasonable, with improved interpretability and greater sensitivity. By prioritizing biological integrity while retaining essential habitat and water-quality information for diagnosis and management, this framework provides a scientifically robust tool for riverine wetland health evaluation, conservation and restoration planning, and evidence-based water-resource management.