Which process increases sediment sorting across an alluvial fan system during periods of decreased discharge?

💡 Explanation

When discharge decreases, the flow competence reduces, and winnowing of finer sediments by wind becomes a dominant process because the receding water leaves them exposed allowing for finer particles to be carried further down the fan gradient. Therefore enhanced winnowing sorts sediments, rather than sediment gravity flows, avulsion reducing, or vegetation stabilization, phenomena influencing different deposition parameters.

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