Steady State versus Transient flow modeling?
WhAEM is a steady state model. Capture zone delineation is usually performed with a steady state model, since time dependent capture zones would be of little regulatory value. If aquifers respond fast to transient forcing (pumping periods), it is best to specify the maximum pumping rates (when the wells are running). However, if the aquifer responds slowly to the pumping periods, it may be more reasonable to specify average pumping rates. Similarly, test point values should be used for conditions of maximum pumping or averages may be more appropriate. The issue of fast or slow responding aquifers is addressed quantitatively in “Analytic Element Modeling of Groundwater Flow” by H.M. Haitjema (1995, Academic Press, section 5.3.7).
