Examining the complexity of discharge-suspended sediment behaviour of a tropical monsoon-dominated river, India

Multiple gauging stations of the Brahmani River Basin, India. This study provides an understanding of sediment transport complexities in monsoon-type rivers and supports informed decision-making for effective river management and environmental conservation. It also underscores the impact of surface landscape, the management of reservoirs and the role of anthropogenic impacts on sediment transport dynamics. River discharge and sediment concentration are measured at four gauging stations of Brahmani River: Tilga, Panposh, Gomlai, and Jenapur. The first three are located in the upper reaches above the Rengali Dam, while Jenapur is in the plain area below the dam. The analysis reveals diverse correlations for fine sediment (<0.075 mm), ranging from linear at Tilga to logarithmic at Panposh and power-law at Gomlai. Medium sediment (0.075–0.2 mm) exhibits linear and logarithmic correlations at Tilga and Panposh while coarse sediment (>0.2 mm) displays logarithmic correlations at Panposh and Gomlai. Total sediment concentrations showcase both linear and logarithmic relationships at Tilga and Panposh, indicating the complexity of sediment-transport dynamics. The study unveils compelling relationships between river discharge and total sediment load (MT/day), with notable power-lla correlations at Gomlai, emphasising the influence of river discharge variations on sediment transport quantity. It underscores the impact of surface geology, the location of reservoirs and the role of anthropogenic interventions on sediment dynamics. • Robust data-based derived discharge-sediment behaviour is examined. • Complex discharge-sediment behaviour (linear, log and power regression) is observed. • Medium and total sediment concentrations exhibit mainly linear correlations. • Coarse sediment displays mainly logarithmic correlations with discharge. • Surface geology, reservoirs location and anthropogenic interventions control sediment dynamics.