By the time the river ends in a standing body of water, for example when it enters a lake, all of this kinetic energy has been converted into thermal energy , or heat energy. This heat energy, uniformly spread through the environment, is the most degraded form of energy and cannot accomplish anything. As this kinetic energy of the moving water is transformed into heat energy it performs work, i.e. the application of force over distance . It is this physical work that moves the water and forms the river into what we see. We will look at this idea more closely.
River morphology is a complex subject.
We subdivided it into the areas below, but you should remember that these are often related to each other. You can visit the pages in the sequence below to get a fairly logical development of the topic, or you can start with whatever area interests you and link into other areas to get any background information you need.