A massive sediment deposition causes reduced channel capacity in an alluvial river system. Which consequence results when threshold shear stress is unmet?

💡 Explanation

Increased sediment from alluvial deposition raises the riverbed through aggradation because the shear stress is insufficient to move the load. Therefore, flood risk increases because the river's capacity to contain discharge is lowered, rather than adapting by braiding or downcutting.

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