As I understand it Hamas has its important people, long range rockets and the bulk of its fighting force in a concrete tunnel complex under Gaza that was designed by an Iranian general and is similar to that used by Hezbollah.
So you would be right in saying the only way to dig them out is with a ground force.
However, Hamas like in previous situations probably has the whole of Gaza booby trapped and will use the civilian population as shields.
So any ground operation would be costly to Israel and Palestinian civilian lives too.
There is no good way to solve this that I can see...
