Catchment runoff results not updating after changing rainfall or catchment information

Product(s): SewerGEMS, CivilStorm
Version(s): V8i, CONNECT Edition
Area: Calculations

Problem

Catchment runoff results (such as cumulative depth, runoff volume and runoff hydrograph) are not changing after making a change to the rainfall information or catchment area, loss or Tc and then re-computing the model.

Solution

If the catchment or rainfall information was changed and the runoff results are not changing after computing the model again, this could be due to the "Always Compute Hydrology" option. In the CONNECT Edition, this is located under Analysis > Compute. In V8i and below, this is located directly under the Analysis menu.

If this option is unchecked, catchment hydrology / runoff will not be re-computed when computing the model. This helps save model run time (improved performance) in cases where the catchment information does not change between hydraulic runs. However if you do make a change to the catchments or rainfall, this option will need to be turned back on in order for the new runoff results to be calculated and used in the model.

Normally you would always have this option enabled so that catchment runoff is re-calculated every time you compute the model. This ensures that any changes you make to the catchments or rainfall will be accounted for, but for large models it can cause the model to take longer to run. If you know that you will not be making any more changes to the catchments or rainfall and the hydrology part of the calculation is taking a long time, then you can safely uncheck the "always compute hydrology" box. Again, this tells the program to simply use the previously-computed runoff for the catchments instead of re-computing it. However, if this part of the calculation takes a long time but there is a chance you might be making changes to the catchments or rainfall, then it is recommended that you keep this option on (checked) so that you do not forget. Meaning, if you had unchecked the box and made some changes to the catchments or rainfall, you might forget to check the box again, compute the model and be confused as to why the catchment results did not change.

See Also

Recommended
Related