Model Structures

The conservation of mass and the conservation of energy are fundamental to building effective models of environmental systems.  In some cases, inputs to a system have been fairly stable for a long period of time and as a result the system reaches a steady (or static) state.  Steady state system models are much simpler to build, execute and interpret.  However, there are many instances in which inputs are not stable and this system becomes quite dynamic (or is in an unsteady state).  These unsteady state models are generally more complex to build, execute and interpret.  

Mass Balances

Steady State vs Unsteady State


Mass Balance for Nodes

© Warren Stiver 2017