Application of DEM, Remote Sensing and Geomorphic Studies in Identifying a Recent [or perhaps Neogene?] Upwarp in the Dibru River Basin, Assam, India

Abstract

The Dibru river basin of Assam is investigated to examine the influence of active structure by applying an integrated study on geomorphology, morphotectonics, subsurface structure, Digital Elevation Model (DEM) using topographic map, IRS 1D LISS III, IRS P6 LISS III, SRTM, seismic and subsurface data. Seismic data reveals existence of an upwarp and an important fault in the basement around the central and eastern parts of the Dibru basin, respectively. The influence of these structures is well observed on all the younger formations inferring their active nature possibly till the Recent Period. Existence of fluvial anomalies, viz. annular drainage pattern, lineaments, abrupt changes in the direction of river course, beheaded stream and valley incision infer role of structural control on the fluvial features of this basin. Most commonly used indices for morphotectonic analysis, viz. basin elongation ratio (Re), transverse topographic symmetry (T), asymmetric factor (AF), valley floor width to valley height ratio (Vf) have been used to identify the evidences of active structures in the area. The values of Re indicated tectonically active, T indicated an asymmetric nature, AF indicated tilting and Vf indicated active incision in the Dibru basin. The DEM, profiles across the valley and superimposed longitudinal profiles of incised channel bed and valley shoulder of the Dibru clearly reveal valley incision by the river. Three large paleochannels located in different parts of the basin had their headwaters towards east at the common source, i.e. the Diyun river. These paleochannels had been resulted when their headwaters avulsed to create new rivers due to affect of the subsurface structures during Recent (or perhaps Neogene?) Period.

A GIS based study on bank erosion by the river Brahmaputra around Kaziranga National Park, Assam, India

“…The morphological and erosional aspects of the Brahmaputra river has been studied by many workers such as Coleman (1969), Goswami (1985), Bristow (1987), Klaassen andMasselink (1992), Thorn, et al (1993) and Kotoky and Sarma (2001) to mention a few. Studies on bank erosion of the river Brahmaputra and many of its tributaries using topographic maps and satellite data have been done by many workers (Sarma and Basumallick, 1984;Kotoky et al, 2005;Sarma, 2002;Sarma andPhukan, 2004, 2006;Sarma et al, 2007Sarma et al, , 2011. Important studies on neotectonics of the eastern part of Assam include the works of Roy (1975), Mazumder et al (2001, Luirei and Bhakuni (2008), and Sarma and Acharjee (2012).…”

Structural controls on topography and river morphodynamics in Upper Assam Valley, India

“…Coleman (1969), Schumm (1977), Ouchi (1985), Schumm (1986), Holbrook and Schumm (1999), Valdiya (1999), Schumm, Dumont, and Holbrook (2000), Jain and Sinha (2005), Das, Dutta, and Saraf (2007), Burbank and Anderson (2012) have carried out work on response of alluvial rivers to active tectonics. Details on active tectonics of the Brahmaputra valley are given in the works by , , Das (2010), Sarma, Acharjee, and Gogoi (2011), Sinha (2012, 2014), Sharma and Sarma (2013). In contrast to these studies, some basement structures within the valley region have not received adequate attention of the researchers.…”