COMPARATIVE ASSESMENT OF DIGITAL ELEVATION MODELS ( DEMS ) IN THE MORPHOMETRIC ANALYSIS OF BHARATHAPUZHA RIVER BASIN

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.