Assessment of geomorphic status and recovery potential in anthropogenically altered river of Eastern India

Abstract

ABSTRACT The study monitors chronological changes (1922–36 to 2023) in channel morphological status of the Mayurakshi River in Eastern India using the index of Geomorphic Status (GS). It encompasses Changes in Sedimentary Units (SU), Changes in Sediment Availability (SA), Changes in Bar Stability (BS) and Changes in Channel Flow (CF). The Index of Geomorphic Status (GS) reveals a sharp morphological degradation of the Mayurakshi River in the recent past. Therefore, a detailed checklist of channel width, bed-level, configuration dynamics and channel connectivity was prepared to identify medium- and short-term Channel Adjustment (CA). The study reveals that instream sand mining and structural interventions coupled with low discharge are the key factors hindering channel morphological recovery. Finally, a new Channel Recovery Potential Index (CRP) has been proposed by considering short-term channel adjustment, sediment connectivity, geomorphological setup and anthropogenic stresses. Preferred alternatives and optional groups assessed from the AHP-TOPSIS and AHP-VIKOR models were used to quantify the channel Recovery Potential. Outcome of the study reveals that reach 1 has more chance of channel recovery (TOPSIS: 0.77 and VIKOR: 0.00) compared to other sectors.