I need to inquire about urban growth in Riyadh, such as some of the problems associated with it, for example, pollution leves in Riyadh, etc.

riyadh is the richest city in the middle east.

Don't exactly know what kind of information you're looking for but Riyadh is a well planned urban city. It wasn't built on following some Master Plan but the authorities have done a good job in making the infrastructure comparable to any good city in the world.
As far as the pollution level is concerned, Riyadh has none! The air is as clean as you'd find in any good urban city.

Can you give us specific questions?