Water Resources Research, Journal Year: 2025, Volume and Issue: 61(5)

Published: April 29, 2025

Abstract Dams heavily regulate the natural hydrological regimes, impacting on riverine ecosystem and local communities. Yet, impacts of dams flow sediment alterations in alpine basins, such as Yarlung Tsangpo River with its immense hydropower potential, remain largely understudied due to limited fine‐scale records. Here, we introduced a dynamic alteration index combined wavelet analysis evaluate time‐varying regimes caused by basin from 1980 2020. Leveraging in‐situ daily observation data, first capture both annual intra‐annual trends extending traditional indicators across three regulation scenarios: unregulated, tributary dam‐regulated, mainstem dam‐regulated. We then explore spectral signatures dam‐induced identify most affected timescales assess dam configuration. Our reveals that despite construction, river discharge increased slightly, decreased low‐flow frequency more common high‐flow frequency. Dam operations markedly altered sediment, disrupted periodicities, weakened flow‐sediment relationships. Specifically, reduction was notable under tributary, moderate degree 45.34%, particularly during main flood post‐flood seasons. Dominant periodicities at semi‐annual scales were nearly eliminated, while preserved. Large events high‐magnitude almost absent, figure‐eight hysteresis pattern indicated transport. These findings underscore need for incorporating dynamics into operation strategies minimize negative transport aquatic ecosystems, providing essential insights sustainable water resource management future planning basins.

Language: Английский