Linking up with Chapter 2, dealing with uniform flow in open channels, it may be noted that any change in the flow phenomenon (i.e. flow rate, velocity, flow depth, flow area, bed slope do not remain constant) causes the flow to be non-uniform. This chapter will
discuss the effect of change in any one of the above quantities, including specific energy, critical depth and slope, and flow types. How to draw water surface profiles will also be introduced.