Order of calculations (Water Overlay)

During the calculation, multiple facets have to be calculated. In each timestep, each aspect of the calculation has to be performed. Although as timesteps become smaller, the exact order of operation becomes less important, the order of operations can lead to specific behavioral details in some uncommon situations.

Calculations are performed in the following order:

• Horizontal surface flow and horizontal ground flow
• Rain
• Building storage
• Sewer inflow
• Surface evaporation
• Groundwater evaporation (saturated zone)
• Groundwater evaporation (unsaturated zone)
• Ground infiltration
• Surface infiltration
• Ground bottom flow
• Exfiltration
• Hydrological constructions (culverts, weirs, pumps, in- and outlets)
• Hydrological areas (sewer overflow, breach in- and outflow)
• Tracer movement, based on the water flow and infiltration which has occurred