Upper VHF is essentially line of sight it is affected and reflected by both to Terrain and by building structures it will Imperfectly penetrate concrete and steel structures. It doesn't have much over the horizon capability.
UHF has better building Penetration, but no over the horizon capabilities.
Range for both is affected by three things 1)Antenna Type/height of the source and its 2)Power and 3)receiver location and orientation.
Under specific Atmospheric conditions, typically a temperature inversion, Tropospheric ducting can occur where RF is reflected further than its normal transmission range and achieve significant over the horizon capabilities. Conceivably this can disrupt local operations.
Essentially the higher you go in Frequency the more line of sight the signal is. Also more power is needed to maintain an equivalent range or the more sensitive a receiver needs to be.
Also sheets of metal will affect all frequency ranges somewhat. This is why the antenna needs to be outside the aircraft or vehicle.