How Do Rivers Make Their Beds?
What happens to all of the stuff that rivers carry? And where does it come from in the first place? In order to answer these questions, we need to talk about erosion and deposition. The term erosion comes from the Latin erosus, meaning eaten away. Erosion in nature is simply the process whereby material is weathered, dissolved, or otherwise worn away from the earths surface. Although wind, glaciers, and waves breaking against the coast may be important in certain places, running water erosion is the most significant globally. This is how a lot of the materials carried by rivers get there in the first place. The factors that determine how much is eroded are climate, vegetation, lithology (what kinds of rocks), and relief (how hilly it is). The 5-10% of earth’s surface that is mountainous yields 80% of the sediment! The opposite process is deposition. The term deposition is from the Latin depositio, meaning lay down. When water slows down, it can no longer carry as much stuff, and partic
