The purpose of this article is to provide for the regulation of nonconforming buildings, structures and uses and to specify those circumstances and conditions under which those nonconforming buildings, structures and uses which adversely affect the maintenance, development, use or taxable value of other property in the district in which they are located shall be permitted to continue or shall be discontinued. This chapter establishes separate districts, each of which is an appropriate area for the location of the uses which are permitted in that district. It is necessary and consistent with the establishment of those districts that those nonconforming buildings, structures and uses which substantially and adversely affect the orderly development and taxable value of other property in the district be discontinued or reduced to conformity as soon as the fair interests of the parties will permit or be permitted to continue with certain restrictions.