River Ecological Health Assessment Based on Microbial Integrity Index and Water Quality Index

• • M-IBI core parameters (Chao1, Sobs, Acinetobacter relative abundance, hgcl-clade relative abundance) were identified through rigorous screening, providing a standardized, multi-metric index for river health. • • Seasonal M-IBI scores followed winter > autumn > summer > spring, indicating significant temporal variability in microbial community integrity, with winter exhibiting highest health status. • • Spatial analysis revealed downstream water quality superior to upstream, suggesting longitudinal gradients in pollution load and recovery capacity. • • WQI and M-IBI results were spatially and seasonally concordant, yet M-IBI demonstrated higher sensitivity to human disturbance and environmental changes, offering earlier warning signals for ecological degradation.