Which characteristic determines the settling rate of alluvial sediments as river flow decreases?

💡 Explanation

When river flow decreases, gravitational settling sorts sediments by size and shape because these factors dominate the hydrodynamic drag. Therefore sediment grain size and shape determines settling, rather than mineral composition, electrical charge or organic content, which have secondary effects.

• Which outcome is worsened by thermocline breakdown during upwelling?
• Which outcome results when wave energy focuses along headlands of an island?
• Which localized effect results when strong katabatic winds flow downslope from Antarctic ice sheets?
• Which risk increases along subduction zones following prolonged tectonic quiet?
• Which lateral effect results when groundwater pressure changes along a transform fault line?
• Which phenomenon causes density currents to transport sediment along lake bottoms after a flash flood?