Geoscience Reference
In-Depth Information
Figure 2:
Multiresolution database logical structure for multiscale hypsometric mapping
In general case the number of LoDs can be less than that of scale series.
For example, city points are often displayed in many scales using different
SQL queries from the same database layer. Desirable number of LoDs
depends on the sensitivity of the data geometry to scale reduction. Brewer
and Buttenfield (2009) investigated this problem and demonstrated the dif-
ference between various geographic phenomena. Among them, relief and
streams are the most sensitive: scale reduction in 2 times or greater require
extensive generalization. So if scales in our series differ in 2-2.5 times,
database for hypsometric mapping should provide LoD for every scale.
Otherwise relief representation would be cluttered in some scales.
