Which consequence manifests when excessive sedimentation overwhelms a levee's capacity?

💡 Explanation

Avulsion occurs when a levee's capacity to contain excess sediment has been reached; channel aggradation via **sediment deposition** raises the riverbed, because this elevates the water level promoting flow shifts, therefore avulsion will occur rather than continued flow containment.

• Which outcome results when differential erosion impacts stacks?
• Which outcome occurs when subsurface pressure exceeds summit vent capacity during slow lava dome growth?
• Which process initiates headwall erosion resulting to expansion of mountain cirques?
• Which outcome will accelerate barrier island erosion when longshore drift weakens?
• Which outcome reduces floodplain biodiversity following levee construction?
• Which process exacerbates debris flow risk on an alluvial fan originating from glacial valleys?