Attack unit located in a river hex

[Gorguss]

In these example unit A is located in a plain hex and unit B is located in a river hex.

Unit A has attack 10 and modifiers 0 in plain hex, -8 in river hex
Unit B has defence 10 and modifiers 0 in plain hex -8 in river hex

1. Unit A attacks unit B
Does unit A attack with strength 10 or 2?
And when unit B retaliates, is this based on its attack value in the river hex?

2. Unit B attacks unit A
Does unit B attack with a strength 10 or 2? Considering the attacked hex is plain.