Riverine landscape dynamics of the Upper Ganga River (Haridwar-Narora), India

Earth observation data provides an exceptional opportunity to study the temporal dynamics of large rivers. The availability of spatially continuous, synoptic and temporally repetitive satellite data allows the reconstruction of historical dynamics of large rivers along with the identification of the causal factors. An absolute paucity of information on the effect of hydrogeomorphic processes on the dynamics of the Upper Ganga River (UGR), especially upon its entry in the plains, motivated this research. This study aims to analyse morphological changes in the river channel, map temporal changes in the land use/land cover (LULC) within the riverscape and thereby understand the landscape dynamics in the UGR (Haridwar to Narora) during 1993-2017 by means of earth observation data. The analysis showed that the river remains straight with a sinuosity index of < 1; however, the braiding increased considerably (from 3.79 to 4.53). Erosion being more prominent on the left bank in comparison to the right bank with 85.89 km² eroded on the left bank in comparison to 59.21 km² eroded along the right bank. Riverine landscape has been observed to have a higher rate of accretion in comparison to erosion (8.09 km² yr^-1 and 6.04 km² yr^-1, respectively). Morphological change has brought a transition in the land use patterns with marked variation in vegetation and agriculture along with built-up. Significant changes in the composition of the LULC are largely due to the manifold increase in the agriculture extent (≈ 12 times), built-up (5 times) and the decrease in vegetation cover from 43.9% in 1993 to just 10.94% in 2017.