A land based aircraft carrier has little practicality for a number of reasons.

The primary reason is that equipment of that size and weight would be so slow as to be essentially immoble on land, and make a hugely attractive target. Moving large equipment already takes a great deal of planning and time, and that's with a route that is prepared ahead of time.

Getting the carrier moving in the first place would require massive amounts of energy, and the mechanics of rolling on the ground would require continual energy output that far exceeds the amount of energy it takes to move a ship.

A ground vehicle with the mass of an aircraft carrier would be so heavy that it could only traverse certain terrain - it wouldn't be able to climb any sort of slope nor would it be able to cross wet ground without sinking in and getting stuck. For obvious reasons, once stuck it would be practically impossible to dislodge.

Finally, it would be a hugely vulnerable target. Countermeasures and mobility are the main defenses against modern bombs and missiles, but a land-based aircraft carrier would sorely lack that mobility. A real aircraft carrier can move over 30 knots / hour, while the largest mobile equipment like the crawler-transporter moves a fraction of that speed - 1 mph. That's on a road prepared specifically for that vehicle to travel over.

Also, there are alternatives such as portable airfields, such as airfields made of pierced steel planking. A team of engineers can prepare and deploy an airfield in only a day or two using modern equipment that is portable with standard trucks or even aircraft. There is also little need for a portable aircraft carrier as modern aircraft generally have the ability to operate from airfields far from the front - for all intents and purposes, with in-flight refueling the only limit to their range is the endurance of their crews.

But, I suppose that if you ignore all of those downsides and insisted on a land-based aircraft carrier, you could possibly create a piece of (track-based) heavy equipment large enough to operate small aircraft - especially STOL / VTOL aircraft - off of. It would be slow and unwieldy, but it could be done.

A land based aircraft carrier has little practicality for a number of reasons.

The primary reason is that equipment of that size and weight would be so slow as to be essentially immoble on land, and make a hugely attractive target. Moving large equipment already takes a great deal of planning and time, and that's with a route that is prepared ahead of time.

Getting the carrier moving in the first place would require massive amounts of energy, and the mechanics of rolling on the ground would require continual energy output that far exceeds the amount of energy it takes to move a ship.

A ground vehicle with the mass of an aircraft carrier would be so heavy that it could only traverse certain terrain - it wouldn't be able to climb any sort of slope nor would it be able to cross wet ground without sinking in and getting stuck. For obvious reasons, once stuck it would be practically impossible to dislodge.

Finally, it would be a hugely vulnerable target. Countermeasures and mobility are the main defenses against modern bombs and missiles, but a land-based aircraft carrier would sorely lack that mobility. A real aircraft carrier can move over 30 knots, while the largest mobile equipment like the crawler-transporter moves a fraction of that speed - 1 mph. That's on a road prepared specifically for that vehicle to travel over.

Also, there are alternatives such as portable airfields, such as airfields made of pierced steel planking. A team of engineers can prepare and deploy an airfield in only a day or two using modern equipment that is portable with standard trucks or even aircraft. There is also little need for a portable aircraft carrier as modern aircraft generally have the ability to operate from airfields far from the front - for all intents and purposes, with in-flight refueling the only limit to their range is the endurance of their crews.

But, I suppose that if you ignore all of those downsides and insisted on a land-based aircraft carrier, you could possibly create a piece of (track-based) heavy equipment large enough to operate small aircraft - especially STOL / VTOL aircraft - off of. It would be slow and unwieldy, but it could be done.