Single Control Volume Method (Single CV)

The Single Control Volume Method (Single CV) is the simplest method to convert volume change to cross section area change. It simply ignores the upstream and downstream cross sections. So the area change is simply the volume change divided by the length of the control volume (the half the downstream distance of the upstream and current evaluated cross sections) and the wetted, mobile, cross section width. The uniform, veneer, elevation change (z) in this method is:

$\begin{array}{l}\displaystyle \Delta z= \frac{\Delta Volume} {W_2 \times (\frac{L_3_2}{2} +\frac{L_2_1}{2})}\end{array}$

Where:
W₂ = the wet, mobile, width of the cross section or the top width of the water within the movable bed limits,
L₃₂ = the downstream distance associated with the upstream cross section (XS₁), and
L₂₁ = the downstream distance associated with the cross section evaluated (XS₂).