Sediment Transport Concepts - Sediment Transport in Irrigation Canals: A New Approach - page 152

D E

dz = Z i,j+1 - Z i,j

B

X i-1

X i

X i+1

Qs i-1

Qs i+1

D

E

Figure 5.33. Schematization of
computations of changes on the
bottom level.

dz = Z i,j+1 - Z i,j

Start from the upstream sub-section to downstream

If start of
sub-section <= end
of section

Y N

Calculate modified bed
level using Lax method
for u/s boundary

Is the
sub-section
initial one?

Y N

Is there
control structure at
u/s section

Calculate modified
bed level using
Lax method for
u/s boundary

Is the
sub-section
last one?

Y

Y

N

N No change in

Calculate modified bed
level using Lax method
for d/s boundary

Calculate modified bed
level using Lax method
for intermediate section

initial bed level

Get value of bed level that will be used to calculate
new value of bed level for the next time step

Figure 5.34. Calculation of the change in the bottom level using the modified Lax method.