Understanding neotectonic induced surface deformation from drainage network using digital elevation models

Abstract

Digital elevation models (DEMs) provide an opportunity to quantify surface deformation in terms of elevation and its derivatives. Darvaz strike-slip fault is a junction zone of the Tajik depression and the Northern Pamirs. The Pyanj River makes a right angle turn after crossing the Central Badakhshan and Henjvan fault system and runs parallel to the Darvaz fault to the southwest on leaving the Pamir to join the Amu River 300 Km southwest. The river profile analysis in this region using SRTM digital elevation model gives information about the tectonic influence on the local drainage network. We create area-slope plot in order to derive channel parameters like concavity and steepness indices that are related closely to surface uplift and deformation. The results show that the Kyzylsu-Surkhab-Vakhsh river system is disrupted by faulting in its middle and lower reaches where they finally join the Pyanj-Amu river system. It is also observed that the main control over the drainage system is tectonic uplift due to ongoing complex faulting because of frequents earthquakes in this region. The quaternary faults in the region control local drainages and the deflection of rivers and stream channels is a further evidence of the recent fault activity. This study can be improved by using high resolution imagery and GPS data.