Geoscience Reference
In-Depth Information
points by using length. Normally, strokes all have different road lengths.
Using topological propetries can also have more sample points than using
road class but less than using length. Thus it is possible for two or more
strokes with the same topological importance in the road network. For
example, the dead end road only has one connection with other roads, and
thus its degree is equal to 1; also it is not used as a link inbetween the
shortest path of other two roads, its betweenness is equal to 0. However,
length is more effective to distinguish the different importance of dead end
roads.
In each distribution, the maximum similarity reflects the goodness of using
a certain property.
Table 1
lists the maximum similarity of using five dif-
ferent properties.
Maximum similarity
Properties
1:50K
1:100K
1:200K
Road class
0.808
0.607
0.560
Length
0.847
0.773
0.680
Degree
0.808
0.658
0.539
Closeness
0.808
0.607
0.468
Betweenness
0.808
0.686
0.642
Table 1:
The maximum similarity of using five properties
In most cases, the maximum similarity is above 0.6. It seems that all the
five properties somehow can be used to determine the importance of
individual roads. Obviously, length property performs better than other
ones. Among three topological properties, betweenness property performs
a little better than the other two.
4.1.2 Evaluation of connectivity
Figure 4
: Plot a series of relationships between the number of selected
strokes and the connectivity of the retained network.
