I asked HEC-RAS 2D to save the simulation results for every time-step of simulation (by checking “write velocity data at the face node locations in 2D Meshes”). My simulation time step is 0.5 second and asked HEC-RAS to report the result every 0.5 second. HEC-RAS successfully saved water depth at each cell centre and flow rates for each cell face for each simulation time step.
Are these saved values the final stage of a simulation time step or an average value during the time step? For example, if the reported flow rate for a cell face at time step 10 is 2 (m3/s), does this represent the flow rate at the start time step 10 or at the end of it? or perhaps it represents the average flow rate throughout this time-step?