How do I stop abandoned buildings in the industry
Judging by the icons above the non abandoned industrial zones your industries have a lack of raw materials.
This can be resolved in two ways:
- Create more transport connections like ports (cargo) train-stations and roads into the area. This will allow industries to import resources from outside your city.
- Create Industries that provide certain raw resources like ore or oil. Check out the appropriate map mode to see if your city contains any of these, then build specialized industrial districts on top of those.
Because you have a very large industrial area it could be that resources simply have trouble reaching your zone. In that case it might be better to create multiple smaller industrial areas around the city so trucks have an easier time reaching them.
There is a mod that automatically demolishes abandoned buildings. Just google "Cities Skylines automatic bulldoze".
If you want to know how to keep the buildings used, the main reason they get abandoned is because a lack of (uneducated) workers, or not enough public transport to the industries. In the picture I don't see any buses or passenger train stops in or near the industry zone.