River and Coast Geo Facts

River and Coast Geo Facts — page 3
River Structure Rivers start out in high areas as narrow fast-flowing streams They become wider and slower as they move downhill toward the sea Source The source is the place where a river starts Rivers can begin as springs where water comes to the surface from deep underground Some emerge as tiny streams of water from melted glaciers or pools of rainwater which run downhill Finding a source It can be difficult to decide exactly where a river begins In some cases there are many small streams that all flow into the same large river Geographers usually consider the source to be the furthest point upstream on the longest tributary Tributaries are small streams or rivers that flow into larger rivers Some rivers begin in damp boggy marshlands In these cases the highest part of the marshland is considered the source of the river Upper course Near the source rivers do not contain much water They are narrow shallow channels that flow quickly downhill This stage is known as the upper course 6