Classification of Geophysical Basins Derived From SRTM and Cartosat DEMs via Directional Granulometries

Abstract

Spatial patterns from terrestrial surfaces have great potential to better understand the surficial phenomena and processes. This article provides an approach for classification of the hierarchically partitioned basins, subbasins, and watersheds with respect to high-directional granulometric index, low-directional granulometric index, and global granulometric index. Grayscale global and directional granulometric indexes of basin and corresponding watersheds derived from Shuttle Radar Topographic Mission (SRTM) and Cartosat digital elevation models (DEMs) of the Lower Indus subbasin of peninsular India are computed. The end results shown are in the forms of watersheds categorized and classified according to global and high- and low-directional grayscale granulometric indexes. It is interesting to observe that the classification of watersheds derived from SRTM and Cartosat DEMs, respectively, yielded similar results, suggesting it would be worthwhile to explore the potential relationships between the directional granulometric indexes of the watersheds and their resistance to perturbations caused by endogenic and exogenic forces. It is also observed that the orientation of watersheds and the general flow direction within those watersheds are in the direction in which the watersheds yield high-directional granulometric index.