The overland flow velocities are discussed in more detail in the section, Output: Overland Flow Velocities (V1 p. 485).
Overland flow in the x- and y-direction
The overland flow in the x- and y- in the list of available output items is used for the water balance calculations.
The cell velocity cannot be directly calculated from these because the overland water depth is an instantaneous value output at the end of storing time step. Whereas, the overland flow in the x- and y- directions are mean-step accumulated over the storing time step. Thus, it is the accumulated flow across the cell face on the positive side of the cell.
You may be tempted to calculate a flow velocity from these values. But, you can easily have the situation where the accumulated flow across the boundary is non-zero, but at the end of the storing time step, the water depth is zero. Or, you could have a positive inflow and a zero outflow, which may be misleading when looking at a map of flow velocities.
H Water Depth, P flux and Q flux
The P and Q fluxes are instantaneous fluxes across the positive cell faces of the cells. These are found in a separate _flood.dfs2 results file, along with the H Water Depth. This file is the same format as the MIKE 21 output files generated by MIKE FLOOD. Thus, you can use this file to generate flood maps etc in, for example, the Flood Modelling Toolbox, or the Plot Composer.
You can also add these values to create flow vectors in the Results Viewer.
TS average, TS min, and TS max
Three calculated depths and velocities are available. These are the Average, Minimum and Maximum velocities and depths over the storing timestep. These values could be useful, for example, when evaluating susceptibility to erosion, or to calculate a flood hazard indicator.