A river may no longer be able to carry a load across its course due to a decrease in water flow, often caused by drought, upstream water extraction, or changes in precipitation patterns. Additionally, sediment buildup can create shallower areas or bars that obstruct the flow, limiting the river's capacity to transport materials. Environmental changes, such as dam construction, can also disrupt the natural flow, reducing the river's ability to carry its load effectively.
The lower course i think...
They settle out as deposited sediments.
Rivers are not all the same. Some are longer than others. It really depends on the river for when it changes course.
The river that you have described is the river Thames. However, the river Severn is slightly longer.
A river usually flows quickly in the upper course, as it is at a higher elevation - mountains streams, waterfalls, etc. In the lower course, it will slow down as the lower elevation means the slope is more horizontal. It is here that the river may start to meander across the valley floor, forming bends, oxbow lakes, and a flood plain.
Seine RiverThe Seine river (777 km) is the second-longest river (entirely) in France. The Rhine, the Meuse and the Rhône are longer, but their course within the French territory is shorter.
The river valley becomes flat in its lower course due to the levels of erosion occurring in the river itself. In the upper course, the river's energy is used for vertical erosion(downward erosion) in order to get to sea level. That's why you see steep V-shaped valleys or Gorges being formed. However, in the lower course when the river is at sea level, a lot of this erosion becomes lateral(horizontal) which is why you see rivers becoming a lot wider in the lower course. Therefore, because the river is no longer eroding downwards there's no longer a difference in height between it and its valley, so the river valley becomes flat.
The activity involves getting your team across a "toxic river" and you only have one pair of boots or something to step on that will get you safely across. The key to this activity is that the team must have members carry people over the "toxic river."
Tradition states that the river was crossed in the course of a few hours at most.
It has the same purpose as any other bridge, to allow passage across a river or another natural obstacle such as a ravine. Bridges usually carry a road, a railway line, pedestrians or a combination of these across a river.
It's the new Marlborough Street bridge. It will carry the Luas and pedestrians across..
It meant that the confederacy could no longer use the river to carry its goods to sea