Eco-Geomorphic Assessment of the Varanasi Turtle Sanctuary and its Implication for Ganga River Conservation

Abstract

The eco-geomorphology of the Varanasi Turtle Sanctuary (VTS) located on the Ganga River in Uttar Pradesh, India was examined for its stability using hydraulic geometry of the channels, such as width, depth and discharge acquired from an Acoustic Doppler Current Profiler, and the mapping of planform morphology from remote-sensing images. Planform maps were generated using Corona and Landsat satellite images for the period 1965-2018. The assessment suggests a well-defined, stable cross-section profile along this stretch of the river. It provides conclusive evidence that the geomorphology of the Ganga River within the VTS has remained stable for the past 50 years, except for some minor changes in the form of bar growth and erosion both upstream and downstream of the sanctuary. Construction activities along the bank, movement of large vessels, sand mining in the sanctuary or dredging of the main channel may destabilize the river geomorphology that will negatively affect the integrity of the VTS as well as the ghats at Varanasi.