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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004
Finally, some extracted valley lines are shorter than digitized
lines.
Figure 9. Digitized valley lines
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Figure 10. Some extracted valley lines at scale 1: 5000
S. CONCLUSION
Extracted valley lines obtained with the program give us
general information about the characteristic of terrain. The
results can be used in hydrological applications and
generalization studies. If threshold value and grid distance of
DEM points are expanded, the valley lines can be used in
middle and small scale maps. On the other hand, it seems that
'RidgeValleyAxisPicker' program is not appropriate to large
scale topographical maps to extract skeleton line properly in
spite of the quite rapidly process time. In conclusion, the
algorithm needs to be developed by adding some
geomorphological and cartographic principals to the program in
order to obtain more accurate results at large scale maps.
REFERENCES
Aumann, G., Ebner, H., Tang, L., 1991. Automatic derivation
of skeleton lines from digitized contours. ISPRS I
Photogrammetry and Remote Sensing, 46, pp. 259-268.
Chang, Y.C., Hsu, S.K., Song, G.S., 1998. Automatic extraction
of ridge and valley axes using the profile recognition and
polygon breaking algorithm. Computers & Geosciences, 24(1),
pp. 83-93.
Mark, D.M., 1984. Automated detection of drainage networks
from digital elevation models. Cartographica, 21, pp. 168-178.
Meisels, A., Raizman, S., Karnieli, A., 1995. Skeletonizing a
DEM into a drainage network. Computers & Geosciences,
21(1), pp. 187-196.
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