Why is upwash and downwash reduced on take-off?

Question

Why is upwash and downwash reduced on take-off?

Answer 1

Actually, IMHO, they would be increased on take off - the aircraft is moving slower and wingtip vortices (the cause of downwash and upwash) are increased when the aircraft is flying at a slower and heavier configuration.  It is the same with landing.  It's the reason small aircraft are warned to allow 2 to 3 minutes before taking off or landing behind a large a/c, and they land beyond the touchdown point, to reduce the effect of downwash.