1. Transient Simulations require: Initial Conditions Storage Coefficient Time step

2. Types of Initial Conditions Static steady state Dynamic steady state Dynamic cyclic conditions (Time distant conditions)

3. MODFLOW allows for two types of storage coefficients: Unconfined storage coefficient (i.e., specific yield) Confined storage coefficient

4. A “convertible” layer in MODFLOW (laycon type 3) is one where cells can convert from confined to unconfined conditions (and back again to confined).

5. Rule of thumb: take at least five time steps per stress period. MODFLOW divides time into Stress Periods. There are multiple time steps in a stress period. Initial  t Parameters in the following packages can be changed with stress periods: WEL, RCH, RIV, DRN, EVT, GHB

6. Rule of thumb: take at least five time steps per stress period. MODFLOW divides time into Stress Periods. There are multiple time steps in a stress period. Initial  t

7. Selecting the time step Can use:  t = Sa 2 /4T for the initial time step of a stress period or find an appropriate time step by trial and error.