Greetings,
As I am aware, SewerGEMS includes the feature of embedding a surface TIN or terrain models along with a stormwater hydraulic model, such that catchment areas can be automatically generated and allocated to their respective nodes/ catchment basins.
Since this is the case, I presume that the maximum distances/ overland lengths within each catchment area accounting for the land slopes, can also be automatically determined using the terrain model.
If this was correct, then at least some of the methods used for determining the Tc values for these catchment areas (Carter, Wallingford(UK), Bransby-Williams methods, etc), would have their input parameters known and the Tc values could be automatically calculated rather than manually inputted in the model. Other methods (such as the Length and Velocity and FAA methods), would require some additional input but a large effort would have been saved by availing the overland lengths and slope values.
Could you please advise on how such a procedure for automating the input of the Tc values could be implemented, in order to avoid or minimize manual input, especially for large numbers of catchment areas?
Thanks and best regards,
Amine Salameh