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Riparian buffer width and stream channel width have different impacts on ecological networks (e.g., plant cover, regeneration, exotics, erosion, habitat, and stressors) and provide various ecosystem services. The protection of riparian zones of increasing widths for higher-order streams and connected tributaries alongside mega-reservoirs and around dams is of great global significance. However, it remains unclear which protection strategies are most effective for such zones. By applying a rapid field-based approach with 326 transects on an inundated area of 58,000 km2 within the Three Gorges Dam Reservoir (TGDR) in China, we found that riparian buffer areas were influenced differently by broad-ranging widths. The riparian buffer width of 101.84 ± 72.64 m (mean ± standard deviation) had the greatest impact on the main waterway, whereas the stream channel width of 99.87 ± 97.10 m was most influential in tributaries. The correlation coefficient strengths among ecological and stress parameters (independently) were relatively greater in the main waterway riparian zones; the highest value was r = 0.930 using Pearson correlation (p

Riparian ecosystem services along higher-order streams and connected tributaries may change over time as disturbances continuously increase, resulting in diverse deterioration of buffer zones. How habitat, plant cover, regeneration, erosion, and exotic parameters (riparian health conditions) change within huge dams and reservoirs worldwide is an unanswered question. We used multivariate statistical techniques to assess changes in riparian health parameters affected by disturbances identified in 304 transects within the Three Gorges Dam Reservoir, China, and associated tributaries. Kruskal-Wallis tests (p 0.01) revealed high diversity in habitat, plant cover, regeneration, erosion, and overall stream condition. There was also notable variance relating to exotic and pressure parameters. The critical variables of riparian health indicators and stress factors identified by principal component analysis explained 58.40% and 74.6% (in the main waterway) and 53.23% and 71.0% (in the tributaries) of the total variance. Among riparian health indicators, one habitat parameter (riparian vegetation width) in the main waterway and one regeneration parameter (tree size classes) in tributaries contributed greatly, along with other specified parameters. Furthermore, stress factors such as farming systems, land-use types, and pollutant activity variables had the highest impact on these water bodies. In comparison, counting stress factors alone showed more deterioration in the main waterway with a range of (r = -0.527- 0.493), as determined using Pearson correlation (p 0.05). Furthermore, after indexing, the parameters exhibited weaker coefficient values in tributaries, where exotic correlated negatively with other indexed values. These findings are relevant for managers of massive dam and reservoir ecosystems seeking to mitigate environmental and socioeconomic losses.