ABSTRACT
A canal is nothing but an open artificial channel used to carry water by means of a man-made river. The water circulating inside a canal runs at a certain speed, producing
mechanical forces between the water and the walls and the bottom of the canal due to its rubbing against them. The influence is mutual; on the one hand, the wet inner surface of the
canal rubbing on the water tends to slow down its movement. On the other hand, the water tends to erode the walls and bottom of the canal, and the energy of the moving water is capable of carrying solid particles that have been either broken off from the canal itself or entered the canal otherwise. The force of the water on the walls and bottom of the canal is a shear force
and is usually called an erosive force (because of its ability to erode the canal by pulling off particles) or tractive (because of its ability to carry the said particles). By the principle of action equal to reaction, the force of the wet perimeter of the canal rubbing on the water is equal to the former and is therefore called by the same names.
