Modeling - Field Sampling: Principles and Practices in Environmental Analysis - page 193

would be separated into plant uptake, erosion, leaching, and precipitation. This would
lead to a much more complex but more realistic model. This increased complexity is
shown in Figure 7.12 [14].
This type of modeling can be very valuable in developing sampling plans that involve
determining natural attenuation, bio- or phytoremediation, or fertilizer use. The rate of
loss can be used to predict future levels of the component of interest and thus the need
and timing of future sampling.
7.7. COMMERCIAL COMPUTER MODELING
Computers and computer modeling have become essential to the whole process of
environmental modeling and field sampling. Computer models
FIGURE 7.12 A complex flow diagram for phosphate in soil (upper triangle
might be fertilizer input, lower triangle might be plant uptake).
can make visualization of the landscape or part of the environment possible. Several
features make these models extremely valuable. First, they are easy to construct and easy
to change when necessary. New information can be added as it becomes available. The
new information can then be added to a visual representation of the area of concern.
Some programs allow analysis and correlation of data. Such questions as where the
contamination ends and how much area is covered by the contamination are questions
that the models can answer.
Figures 7.13 and 7.14 show two types of outputs that can be obtained by this type of
program. These are representations of the concentration of a pollutant in a field as