An example of a "back of the envelop model" which is an important first step in any modeling exercise. "Back of the envelop models" are used when you are trying to get a rough estimate of the flow through a system, the budget, or the response to a stress. They are simplistic as can be. This is often the kind of modeling you do on a napkin at lunch, or the back of an envelop in an airplane.
Given the limited information from the diagram below, estimate the ground-water flux through the lake.
There are many alternative results depending on the conceptual model you select. Of course some will be better representations of the true field conditions than others. We would like to use field observations to determine which model best represents the system. When the observations are not sufficient to differentiate between the models, then a range of models needs to be evaluated and a range of answers provided. Explore the following alternatives:
LAKE FLUX EXERCISE KEY OPTION #1
LAKE FLUX EXERCISE KEY OPTION #2