A nonconforming use of a building or land which has been abandoned shall not thereafter be returned to such nonconforming use. A nonconforming use shall be deemed to be abandoned when any of the following events occur:
(a) Owners' intention to abandon is apparent.
(b) When abandoned for a period of more than one year.
(c) When the characteristic equipment and furnishings of the nonconforming use have been removed from the premises and have not been replaced by similar equipment within the period of ninety days unless other facts show intention to resume the nonconforming use.
(d) When nonconforming use has been changed to a conforming use or a use allowed by a special permit.
(1960 Code 7-308)