Network computation

If there is no negative discharge, the network is calculated in the upstream-downstream "topological" direction as given by Talweg.

At a node, the concentrations C_{p} and C_{b} of incoming offtakes and reaches are known and give C_{nd} and C_{b} for outgoing offtakes and reaches using the node mass balance equation :

C_{b}=C_{\mathit{nd}}k_{b} if the distribution coefficient is defined as fix
C_{b}=C_{\mathit{nd}}k_{b}k_{a} if it is defined as adjustable.

Negative discharge in reaches are not yet implemented in the quality module.