The East Third Ring Road of Baoding City is neither a southern city nor a northern city: it is the Lianhuachi District of Baoding City.
The Heather District and Northern District you mentioned were the names of the urban areas ten years ago. For the economic development of Baoding, the urban zoning and city name were updated. Now its eastern part is called Lianhuachi District, its western part is called Jingxiu District, and its northwest part is called Gaoqi District. Three new districts were added: Qingyuan District, Xushui District and Mancheng District.