Abstract:
A study on comparative assessment of Digital Elevation Models (DEMs) in the
morphometric analysis of Bharathapuzha river basin was done in Kelappaji College of
Agricultural Engineering and Technology, Tavanur. The objective of the study was to
statistically analyse the suitability of different DEMs in the morphometric studies of
watershed.
Five different DEMs were selected for the study i.e. GTOPO, ASTER DEM,
CARTODEM, ALOS and SRTM DEM. The aerial and linear morphometric parameters
of study watershed was found out using each of these DEMs and the results were
compared. Then statistical analysis was done, in the elevation point of view, using
Google Earth as reference.
It was observed that ALOS and ASTER DEM performed better in
morphometric analysis when compared to other DEMs. This observation was validated
in the statistical analysis with ALOS and ASTER having the least error among all. On
the other hand GTOPO was found to have the maximum error.
The results clearly showed that ALOS and ASTER DEM are more effective for
the morphometric studies of river basin. SRTM DEM could be recommended for higher
elevation points (>100 km) and CARTODEM for both lowest (<300 km) and highest
elevation (>1750 km) areas.
