<p>This study investigates the evolution of downsized barchan dunes in a water tunnel experiment, emphasizing the influence of inflow velocity on their crescent-shaped attractor. Based on image processing methods, the kinematic and morphological features of barchan dune evolution are determined. The results reveal that the varying inflow velocity will affect the crescent-shaped attractor. Furthermore, a cubic relationship is established between flow velocity and the aspect ratio of barchan dunes. Additionally, there is a morphological threshold in the evolution of the crescent-shaped attractor to evaluate its stability. This study highlights the sensitivity of the crescent-shaped attractor to inflow velocity and confirms its steady evolutionary pattern, and it provides a new perspective on the formation of the barchan dune swarms in the field of wind-blown sand dynamics.</p> Graphical Abstract <p></p>