Initial condition

we have the analytical solution in the CONDIN soubroutine of the Fortran file. we used Newton method.

the analytical solution is given by the following formula :

H_{0 }= ZF(x) + H(x) + Q^{2}/(2gL^{2}H(x)^{2})

L the width of the channel,

ZF the cote of the bottom,

H the watter heiht.

Q the flow rate.

g the gravity acceleration.