Segment Groups
 
Model segments are aggregated according to the GROUP numbers specified on the 'Case Edit Segments' screen.
 
GROUP numbers are integers between 1 and the total number of segments (<=50). GROUPS are generally intended to reflect distinct regions, such as separate lakes, separate basins, or separate reservoir tributary arms.  For a lake or reservoir with one basin, all GROUP numbers would normally= 1.
 
Segments within the same GROUP are assigned uniform rate coefficients in implementing phosphorus and nitrogen retention  models and simulating the effect of hydraulic residence time on algal response using Chlorophyll-a Models 1 or 2 .