ABSTRACT
Indian rivers are progressively subjected to regulated, irreversible flow and sediment regime, initiating a potential for metamorphosis. Moreover, anthropogenic activities like sand and gravel mining, inset floodplain encroachment, riparian vegetation cover loss can generate further stress in natural river systems. Hence, assessment of direction of change and potential for river recovery (restoration) is crucial for future riverine management and sustainability programs. River recovery potential signifies pathway of degradation and recovery on the basis of predictions about directions of change. This present research is focused on assessing change point of sediment load and river recovery potential in Mahanadi River basin. The Mahanadi River basin has been subjected to alteration in flow and sediment regime due to construction of small to large dams, weirs and barrages. Long term hydrological data (1980-2010) consisting of flow, sediment and channel cross-section (at-a-station hydraulic geometry) have been utilized to understand river recovery potential and geomorphic assemblage characteristics in pre-disturbance and post-disturbance periods. Pettitt’s test of change point analysis reveals, alteration of sediment regime in between 1990-2000 for main stream of Mahanadi river (Tikarapara) and tributaries (Hasdeo and Mand). This shows, decrease of sediment load in recent decades due to growing human impacts. The geomorphic analysis also suggests, degradation is prominent (0.5–2.0 m) in low-flow channels during post-disturbance period. Finally, the overall river recovery assessment of sub-basins and mainstream may confirm to “transfer” river style in the relaxation time period.
