Page 23 - Interp Book

Vegetation Modeling and Mapping.
Different combinations of landcover with different soils, slope, hydrology, or ecoregions
were assigned to different final mapped Ecological System and Mapping Subsystem
vegetation types. For example, the cold deciduous forest landcover type on a floodplain
was assigned and mapped as a floodplain ecological subsystem, whereas cold
deciduous forest on a slope >20% was assigned and mapped as a slope forest, and so
on (Figure 5).

Figure 5. One landcover type (deciduous forest) may have been mapped as several different ecological
system or mapping subsystem vegetation types based on modeling by use of abiotic differences.

Python scripts accessing the ArcPy interface to ArcGIS were used to generate modeling
rules using combinations of land-cover and abiotic attributes. This provided a flexible
and transparent method for model implementation. Additionally, much of the basic
implementation of the models was accomplished inside MS Access using Visual Basic
for Applications (VBA) modules. Accomplishing this part of the task was much more
time efficient in MS Access than it was using complex joins and calculations within
ArcGIS.

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