plawolf
Lieutenant General
In case of a blocked runway you will lose all aircraft in the air, if you are not in range of an airbase.
They can clear the runway! If the arresting wires are damaged, they can repair that as well, and send up additional J15s with buddy refuelling probes to top up incoming aircraft low on fuel.
In fact, I am fairly confident they trained and practice exactly for contengencies like those long before this cruise, as part of the work up and qualification exercise to prepare for long range operations far from back up land bases.
Short of a Forestall style massive fire incident, its hard to think of any other peacetime situations that might arise which would force the carrier's air wing to have to seek to land elsewhere or mass ditching their jets. But that's the sort of risk all carrier long range operations take, so I don't see why there would be anything special about the Chinese experience compared to the likes of the Uk (not right now I know), France Russia and the US.
And it's not like having 20 aircraft onboard means they need to launch all 20 all the time. Although it will be a useful exercise for them to launch a full flight deck, then pull up the rest of the air wing from the hanger and launch those, then do a massed recovery op where more planes than can be parked on deck are recovered and turned around for another sortie.