Line, etc. Why is the total head line drawn like this in hydraulics?

The total head is equal to the piezometric head plus the velocity head. When the flow velocity is large, the flow velocity head is large and the piezometer head is small, so the head line is like this. The abrupt change of water head line indicates local water head loss.

As for why the piezometric head line does not coincide with the total head line when v=0? V refers to the speed in the pipeline, not the speed in the pool, which does not exist here.