When the Zoning Officer cannot definitely determine the location of a zoning district boundary by lines of streets or center lines, by the scale or dimensions stated on the map, or by the fact that the boundary clearly coincides with a property line shown on the map, the Zoning Officer or the Zoning Hearing Board, upon appeal, shall interpret the location of the zoning district boundary with reference to the nearest property lines indicated by the Westmoreland County Tax Base Maps on file and bearing district boundaries marked by the Department or Zoning Officer, and the scale of the Zoning Map and the intentions and the purposes set forth in all relevant provisions of this chapter.