Analysing the role of anthropogenic intervention in reconfiguring the hydromorphology of the sub-Himalayan river systems in India: a comparative assessment between the Mahananda–Balason and Chel–Neora systems

This study compares the hydromorphological quality of two sub-Himalayan Rivers, the Mahananda–Balason system (MBS) and the Chel–Neora system (CNS), to analyse the role of human intervention in channel hydromorphology. An indicator-based assessment, developed by Mitra et al. (Adv Space Res 71:1397–1417, 2022), is adopted here to obtain the hydromorphological quality. A hypothesis test using a two-tailed t-test and principal component analysis (PCA) is performed to identify the reaches with similar hydromorphological conditions along with aspects that needed restoration. Results show that the hydromorphological condition is highly influenced by the intensity of human alterations, and their interrelations are strongly proportionate. While the hydromorphological quality of unconfined MBS is highly degraded, that of unconfined CNS and the confined reaches of both systems have remained almost at their least disturbed condition (LAC). Intensive human interventions on MBS have impacted the groundwater table, riverine sediments, and fish habitat. Now, to maintain sustainability regarding riverine resources of CNS, close and regular monitoring must be initiated, and this methodology can serve that purpose. Being dependent on monitoring the ongoing interventions and the channel's physical forms, assessment protocols like this can serve the purpose of rapid hydromorphological assessment for the river systems of data-scarce regions.