China has introduced an amphibious Tributary Engineering Recon Vehicle for its engineering units. The five ton truck is designed to survey China's many rivers.
This information would be useful for building bridges, fording rivers, or using rivers for transportation.
I have to ask, are the Chinese really worried about being invaded? Do they really think they'll need to use their rivers internally for transportation or need to cross them with new bridges?
Where, or where, could there be rivers that the Chinese might need to cross? Well, there's the Brahmaputra River in northeast India. The Indus River in Jammu and Kashmir. And the Amur, Amgun, and Zeya Rivers in Russia's Far East. Or even the Irrawady in Burma.
I mean, if you want to think about where the Chinese might be interested in crossing rivers with their army that doesn't involve their own.