The parallel versions of the hydrology and vegetation components
are very similar to those of the sequential model. Since each
processor owns
a portion of the map, and map data in any grid cell are
independent of any other, no interprocessor communication is
involved. For hydrology updates, the same interpolation method
to redistribute water levels from the 2mi scale to the 100m scale is used
(as explained in Section 2.3). However,
each processor computes water levels for its map portion only.
Similarly, each processor is responsible for updating forage growth in both
the high and medium quality classes of forage in only the locally owned
grid cells. Thus, each of the 32 processors updates hydrology and vegetation
values in approximately 
of the study area.
Excellent speed improvements for both components were achieved
through parallelization and are presented in Section 4.