Impact of Gravel Mining on River System Stability

Data from the Lower Mississippi River are presented and analyzed relative to trends which may be attributed, in part, to the removal of the gravel armor from the bed of the river by gravel mining. A significant change with time of both the size and gradation of the bed material of the Lower Mississippi River is documented. The data presented indicate a possible relationship between gravel mining and the development of divided flow reaches. While the available data are not sufficient to establish a direct cause-and-effect relationship between gravel mining and river system instability, the correlation is sufficient to serve as a warning of a potentially serious problem. The indiscriminate removal of gravel from river beds may be activating far-reaching changes in system morphology.