Health assessment of Northern Jiangsu Section of Beijing-Hangzhou Grand Canal based on Benthic Index of Biotic Integrity (B-IBI)

The Benthic Index of Biotic Integrity (B-IBI) has been widely used to assess the ecological health of river ecosystems.Based on an analysis of the impact of shoreline utilization types on benthic macroinvertebrate community structure, this study applied the B-IBI to evaluate the ecosystem health of the Northern Jiangsu Section of the Beijing-Hangzhou Grand Canal, which serves as the source area for the Eastern Route of the South-to-North Water Diversion Project.Redundancy Analysis (RDA) was also employed to identify the main environmental factors influencing the ecological health of this canal section.The results showed that: ① 33.3% of the river segments in the Northern Jiangsu Section of the Beijing-Hangzhou Grand Canal were in a healthy state, while 40.0% were in poor or lower conditions.The spatial distribution of health status followed a pattern of better conditions in the northern sections than in the southern.② Natural shoreline segments provided more favorable habitats for benthic organisms, with significantly higher benthic community diversity and better ecological health compared to artificial shoreline segments.③ RDA results indicated that the proportion of natural shoreline, electrical conductivity (EC), and ammonia nitrogen (NH₃-N) were the key factors influencing the ecological health of this section of the canal.This study provides scientific references for shoreline protection and ecological restoration in the Northern Jiangsu Section of the Beijing-Hangzhou Grand Canal.