Here you can specify results that should be integrated over time. The integrated results will be placed in the post_integrate_result record with the same index.
An example looks like:
...
groundflow_pressure
groundflow_velocity
end_initia
...
post_node 1 -average -geometry_line 4
...
post_integrate 3 -post_node_result 1 -gvely
...
...
Here the post_node record first takes care that the average groundflow y-velocity at nodes on a line are determined, among other unknowns. The post_integrate record integrates that average groundflow y-velocity over time. In this way the total groundflow debit volume over a line is registered.