drawdowns map

hi Mr. Peter  :) :)
the simulation of model in transient state is ok, but i have some questions about drawdowns map.
I took a period of time for simulation of model from 1972 to 2008.
so How do I show the map of drawdowns in model between these two periods

thank you very much

yahia alwathaf

After loading the results file in the Classic FEFLOW user interface (5.4, 6.0 Classic), in 'Special Operations' you can choose a temporal difference calculation.