Jiangxi province, places therein
贛 centers on a specific geographic reference: Jiangxi province and locations within it. It does not carry a broad abstract meaning beyond this proper-noun usage.
贛 is a complex character whose historical development is uncertain. It is used primarily as a proper noun for Jiangxi province, and its component breakdown does not yield a clear semantic story.
贛 looks like a container wrapped around 貢. Think of it as a special label for Jiangxi province, with the inner 貢 hinting at something valuable or tribute-like from that region.
For コウ, imagine a proud local from Jiangxi saying 'Koh!' (an invented exclamation) when showing off their province: Koh -> コウ.
Gan Chinese (language)