Applicability of SRTM data for landform characterisation and geomorphometry: a comparison with contour-derived parameters

Suitability of spaceborne digital elevation models of different scales in topographic analysis: an example from Kerala, India

“…In this study, ASTER and SRTM show relatively smaller variability in elevation with respect to TOPO and hence smaller variability in relative relief (see supplementary Appendix 1 for definition). Such a close similarity in relief parameters between DEM derived from topographic maps and SRTM was previously reported by Prasannakumar et al (2011). The cumulative area under different relative relief classes of TOPO and SRTM has also significant similarity, compared to ASTER and GMTED (Fig.…”

“…The estuarine region of the basin has been excluded in the study because of voids and other spurious points such as anomalously high (spike) or low (well) pixel values. The river basin is developed on the metamorphic rocks of the Kerala Khondalite Belt, one of the largest granulite facies supracrustal terrains of South India (Soman 2002;Prasannakumar 2007). Predominant rock types in the basin include garnetiferous biotite gneiss, garnetiferous quartzofeldspathic gneiss, charnockite gneiss, pyroxene-and calcgranulites.…”

“…All the analyzes were carried out after projecting the DEMs from Geographic Coordinate System (WGS84 datum) to Universal Transverse Mercator (zone 43 N), since all studies employing DEMs make use of planar coordinates to have the same measurement units for x, y and z directions or longitude, latitude and elevation (Prasannakumar et al 2011). In order to improve the quality of the DEMS, spurious points/outliers in the data were removed by applying a low pass filter with 3 9 3 kernel neighborhood.…”

Impacts of DEM resolution, source, and resampling technique on SWAT-simulated streamflow

“…Moreover, a set of contour lines of 20 m intervals were collected from the same department to generate a baseline DEM with 20 m resolution (ID 1) (Table 2). Similarly, Prasannakumar, Shiny, Geetha, and Vijith (2011) and Thomas, Joseph, Thrivikramji, and Arunkumar (2014) also generated a 20 m resolution DEM using a contour map of 20 m interval that extracted from a topographic map. They used this generated DEM as a reference for comparison with other DEM products.…”

“…The DEMs from various sources should be resampled to the same spatial resolution for more accurate comparisons (Prasannakumar et al, 2011). Hence, the ASTER GDEM2 and GMTED2010 were resampled to 90 m resolution to match the resolution of SRTM v4.1 and EarthEnv-DEM90 (Table 2).…”