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COMPARATIVE EVALUATION OF DIGITAL ELEVATION MODEL BASED ON ELEVATION DATA AND TERRAIN ATTRIBUTES LEADING TO THEIR VALIDATION
  • Ankita Sharma,
  • Bhaskar R Nikam,
  • D S Bagri
Ankita Sharma
HNB Garhwal University

Corresponding Author:[email protected]

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Bhaskar R Nikam
IIRS
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D S Bagri
S.R.T. Campus
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Abstract

Digital Elevation Model (DEM) is the 3D-representation of terrain surface in the discrete form and a standard tool to examine the hydrological and research application related to terrain characterization, landscape and water resources management. It helps in identifying physical features of an area, watershed delineation and stream network generation. However, several issues related to DEM’s accuracy is the utmost concern for researchers. The present study is based on the comparative studies of DEMs viz., Cartosat-1, SRTM, ALOS and ASTER having the same spatial resolution of 30m each, under two different categories of elevation data and topographic attributes. The vertical accuracy of DEMs is examined by using ground control points as a reference level of elevation generated from topographic map. Analysing different sources of error in the DEMs, the RMSE and MAE based validation of elevation suggests that Cartosat-1 shows relatively high vertical accuracy (RMSE=45.2 & MAE=7.7) and ASTER shows the least (RMSE=60.5 & MAE=34.6). The grid size, spatial variation and vertical accuracy of DEM are among the prime attribute of data sources to determine the variation in basin morphometry. The study area shows a gradually undulating topography with 5 th order drainage network. An inference can be made out of research study that the mean elevation values of ALOS, SRTM, Cartosat-1 are relatively lower than ASTER whereas differences in stream parameters are also observed.