Nonconforming use of land. Where no building or structure is involved, the lawfully existing nonconforming use of land may be continued; provided, however, that no such nonconforming use shall be enlarged or increased, nor shall it be extended to occupy a greater area of land than that occupied by such use at the time of the first adoption of this chapter, unless specifically allowed by other provisions in this chapter, nor shall any such nonconforming use be moved in whole or in part to any other portion of the lot or parcel of land occupied by such nonconforming use at the time of the adoption of this chapter; provided, further, that if such nonconforming use of land or any portion thereof ceases for any reasons for any continuous period of more than one year, or is changed to a conforming use, any future use of the land shall be in conformity with the provisions of this chapter. No nonconforming use of land shall be changed to another nonconforming use.