If you crouch, especially with the white snow, it is very blinding actually. Pretty good but why rivers? That ruins the purpose of digging because you can only reach your own land.
And since nobody explained this to the people who "see no trenches". Trench wars is where you dig your own trenches and use the dirt to build walls.
For the map: Pretty good, but I agree with frontrox, you could grab a sniper and spawn-kill the people across from you. And instead of making server admins, just put on votekick or voteban.