1. Role of effective discharge on morphological changes for a regulated macrochannel river system.
- Author
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Pradhan, Chandan, Chembolu, Vinay, Dutta, Subashisa, and Bharti, Rishikesh
- Subjects
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WATERSHEDS , *FLUVIAL geomorphology , *SEDIMENT transport , *SUSPENDED sediments , *STREAM restoration , *ANALYSIS of river sediments - Abstract
Effective discharge plays a major part in sediment and nutrient transport, landscape modification, and river restoration. However, a complete understanding of effective discharge is still missing because of heterogeneity in various fluvial processes. The present study investigates the role of effective discharge for suspended sediment transport in a regulated macrochannel river system, the Brahmani River, India. The natural flow-sediment regime and channel pattern of the Brahmani River have been altered by the Rengali dam. The effective discharge is estimated with both analytical and deterministic methods using long-term hydrological data. The results show the control of regulated flow and sediment regime in the post-dam period contributes to the reduction in effective discharge (1849 m3/s to 820 m3/s), where frequent moderate floods are able to transport a maximum portion of sediment load. An effective discharge integrated stream power curve is formulated, which accurately predicts the channel transition (from sinuous to weakly braided) in the post-dam period. Finally, the proposed probability of braiding captures the chute formation correctly, which further highlights the hierarchy of energy dissipation and morphological continuum in the Brahmani River. A conceptual plot showing the link between observed geomorphic units, morphological analysis and process-based stream power estimation. [Display omitted] • Effective discharge converges to a moderate flood in the macrochannel Brahmani • Effective discharge integrated stream power curve predicts the channel transition • River goes through transition to accommodate effective discharge in inset channel • Proposed probability of braiding accurately captures the chute formation [ABSTRACT FROM AUTHOR]
- Published
- 2021
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