DOI: 10.5176/2251-3353_GEOS14.49
Authors: Jahanzeb Qureshi, Syed Amer Mahmood, Amer Masood and Shahid Ghazi
Abstract: The Potwar Plateau is a lower part of North West Himalayan fold and thrust belt and is a result of ongoing subduction of Indian plate beneath Eurasia. The objective of this investigation is to identify active tectonics and associated severe topographic deformation through geomorphic indices from Digital Elevation Model (DEM). The Shuttle Radar Topography Mission (SRTM) DEM with a resolution of 90 m is a good dataset for such analysis. The stream-length gradient index, concavity, steepness, relative uplift rates and isobase map were extracted automatically using standard algorithms. Comprehensive analyses based on geomorphic indices, Landsat imagery and available geological maps revealed a relationship between these indices and neotectonics. These analyses also indicate direct control of neotectonics over the local topography drainage network. The steepness index shows that the northern Potwar is more elevated than the southern Potwar. The spatial distributions of variable uplift rates are indicative of unique surface deformation within the Potwar plateau. The isobase map revealed different local base-level inconsistencies that corresponds to the prominent active structures and lithological demarcations as presented in the printed geological maps. The orientation, deflection and interruptions of the local base levels correspond well with the local active tectonics, regional uplifts. The visual interpretation of Landsat imagery shows major tectonic control over drainage network and offsetted streams which is consistent with river longitudinal profile analysis.
Keywords: DEM; river profile analysis; isobase; neotectonics; Potwar Plateau
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