Jiang in Chinese / Japanese...

薑 is the Chinese, Japanese Kanji, and old Korean Hanja word for ginger root (Zingiber officinale).

薑 is also the Chinese surname Jiang, or the Japanese surname Hajikami.

Sometimes, this can refer to a Japanese pepper (Zanthoxylum piperitum).

江 means large river in Chinese, Japanese Kanji, and old Korean Hanja. This generally refers to a river big enough that it's navigable by cargo boats, passenger boats, or small ships.

In Japanese, this can be a surname when pronounced as Minkou or just Kou.

強 is a character that means strong, strength, force, powerful, better, stubborn, and stiff (yes, all of this in one character).

This “strong” has less to do with physical strength and more to do with having a winning attitude, or just having the ability to win at something.

Note that most of the time, this character is pronounced “qiang” but when used with the meaning of stubborn, unyielding, or stiff, it is pronounced “jiang” in Chinese.

Also, sometimes “qiang” is used in modern Chinese to describe people that do crazy things (For example: Bicycling from Beijing to Tibet alone). I sometimes can be found outside my Beijing apartment wearing nothing but shorts and a tee-shirt while eating ice cream during a snow storm, just to hear my neighbors call me “qiang.” Maybe they mean “strong” but perhaps they are using the new meaning of “crazy strong.”

強 can also be a Chinese surname that romanizes as Jiang in the mainland or Chiang if from Taiwan.

強 is a valid Korean Hanja character with the same meaning but is mostly used in compound Korean words.

強 is used in Japanese (though normally in compound words). In Japanese, it has the same meaning but in some contexts can mean “a little more than...” or “a little over [some amount].” Most Japanese would read this as tough, strength, stiff, hard, inflexible, obstinate, or stubborn.

The variant 彊 is sometimes seen in older literature.