When a river starts meandering, the sediment carrying capacity: 

Explanation:

During floods river carries silt charge in excess of the quantity required for stability, the river starts building up its slope by depositing the slit on its bed. This accretion is the primary process, which consequently leads to meandering.

The increase in slope tends to increase the width of the channel and the sediment carrying capacity decreases.

Finally due to shifting of the convex bar, the width between the banks reduces, which increases the velocity and sediment carrying capacity also.