Rivers shape landscapes over time through erosion, transportation, and deposition. As rivers flow, they erode the surrounding land by carrying away sediment and rocks. This erosion creates valleys, canyons, and other landforms. The sediment that is transported by the river can be deposited downstream, forming floodplains, deltas, and alluvial fans. This continuous process of erosion, transportation, and deposition by rivers gradually changes the landscape over time.