ISLET IN A RIVER: TRANSPORTATION PHENOMENON OF SANDS IN WATER

By introducing the ancient Chinese poem "a boat is moved to moor at a misty sandbar", we discuss the amazing transportation phenomenon of sands in water in the frames of poetry and mechanics. We reveal the key role of water in shaping the landform, mainly includes the erosion, transportation and sedimentation processes. All of them have considerable effects on the formation of landforms. By analyzing the Stokes number, we discuss the motions of suspended sand particles in the moving fluid, which result in either the transportation or the deposition modes of sands in the river. Furthermore, we take typical islets as examples to reveal the amazing mechanism of hydraulic effects and resulting landform evolution.