Surface velocity (m/s, x and z) of a river from the gradients of its water level and of the
channel strength: downhill along the level, with the across-channel part removed (water runs
along the channel), at flowSpeed·√(slope / 1%), faster mid-channel.
Surface velocity (m/s, x and z) of a river from the gradients of its water level and of the channel strength: downhill along the level, with the across-channel part removed (water runs along the channel), at
flowSpeed·√(slope / 1%), faster mid-channel.