Data of paper “An Improved Physical Model for Open Channel Confluences： Bridging the Gap between Laboratory and Field Observations”

This study addresses the discrepancies between flow structures and bed features observed in natural river confluences and those reproduced in laboratory experiments. An improved, generalized physical model is proposed to better replicate typical characteristics of natural confluences—such as rounded downstream confluence corners, high width-to-depth ratios in the downstream channel, and downstream channel widening relative to the upstream. Using flow parameters commonly found in natural settings, a series of flume experiments were conducted to measure flow structures and bed morphology. The results revealed flow and bed characteristics more representative of natural conditions, including the absence of a separation zone and the formation of a scour hole originating at the upstream junction corner. Furthermore, the study establishes the relationship between bed evolution and flow structure, identifying the dominant driver of scour hole formation as the intense turbulent kinetic energy and high shear stress within the shear layer.