Multiple channels exist at this point on the fan, but the one in the center is dominant. Note also the meander bend migration evident, although entrenchment is not as evident. This oblique view upstream is after a days worth of flow and the fan now spans the width of the table. Note that the left side is the active side. This shows a close-up of the front where individual lobes of sediment are evident.
Much longer lobes are evident at deltas of rivers such as the Mississippi.
With time the above water portion of the lobes of the Mississippi delta disappear due to subsidence from compaction of underlying sediments and from wave action and erosion due to Gulf storms. Those interested in reading more about river channel switching and lobe abandonment may want to read Controls on Nature by John McPhee . One more interesting feature that can be modeled is the patterns of sedimentation caused by a sea or lake level increase or decrease. In this photo you can see two lobate depositional fronts. The higher one was formed when the water level was higher, and can now be considered a paleo-shoreline.