Scouring that occurs in cross-section a river can be caused by morphological conditions of the river and the effect of bridge piers that obstruct the flow. Availability of piers and abutments can cause the stability of soil base granules to be disrupted. downflow. and horseshoe vortex that causes soil base granules around the bridge pier to be transported the flow that causes occurren... https://www.bekindtopets.com/