What does it mean to cancel busy arrival on a large scale?

The plane can't get into the parking space.

There are many cases of plane delays and flight cancellations. The plane is affected by the weather. In order to ensure the safety of passengers, take-off and landing are not allowed in bad weather. So the plane can't enter the port.

Arrival means that the plane lands at the airport and slides into the pre-arranged seat after landing, that is, the plane enters the parking space. Inbound busyness is the number of inbound aircraft. The more times, the busier, and vice versa.