A stream is simply a body of flowing water.
It is smaller than a river.
All streams start at some high point. The high point can be a mountain, hill, or other elevated area. Water from some source like a spring, snow melt, or a lake starts at this high point and begins to flow down to lower points.
Streams can take on different shapes, depending on the landscape through which they flow.
They are important as conduits in the water cycle, instruments in groundwater recharge, and corridors for fish and wildlife migration.
Streams have a major role in geology. They sculpt and shape the earth’s surface by eroding, transporting, and depositing sediment. By eroding sediment from uplifted areas and creating landforms made of deposited sediment in lower areas, streams shape the earth’s surface more than glaciers do, more than waves on a beach do, and far more than wind does.
There are about 8 different stream types:
• Alluvial Fans
• Braided Streams
• Ephemeral Streams
• Intermittent Streams
• Perennial Streams
• Straight Channel Streams
• Meandering Streams
Alluvial Fans form when water flows through mountains, hills, or canyons. As the water moves downhill, it collects sand, silt, and other paritcles-alluvium.
Braided Streams are found close to very high mountains. They have multiple channels that continuously branch and join along the entire length of the stream, which in turn creates numerous longitudinal bars between the channels.
Deltas result when streams enter a standing body of water, usually an ocean.
Ephemeral Streams are temporary types of streams that only occur after snow has melted or after heavy rainfall.
Intermittent Streams are those streams that usually flow during the wet season – usually winter through spring – but which are typically dry during the hot summer months.
Perennial Streams have water flowing through them all year long, and the source of the water can be either surface water, groundwater, or both. This doesn’t mean that there is water in every inch of its bed, but at least part of the stream will have some water in it.
Straight Channel Streams are not perfectly straight, but have no major twists and turn about them, and these are called straight channel streams.
Meandering Streams consists of large loops that flow across a wide flat floodplain and are surrounded by valley walls.
Streams flow downhill due to the force of gravity. The higher the hill, the more gravitational energy there is to drive the stream. Where the slopes are steepest and the hills the highest, the streams will be the most energetic and the rate of erosion will be fastest.
Some streams flow underground through unconsolidated sediments or through caves. Especially with caves, a stream may flow aboveground for part of its course, and underground for part of its course.
When a stream flows over an especially resistant stratum and forms a waterfall or cascade, or the same results because for some reason the base level of erosion suddenly drops, perhaps as a result of a fault, the resulting sudden change in stream elevation is called a nickpoint. The stream, of course, expends kinetic energy in “trying” to eliminate the nickpoint.
There are a number of regional names for a stream:
In North America: Branch, Creek, Falls, Kill, Run and Brook
In the United Kingdom: Allt, Beck, Bourne, Brook, Burn, Gill, Nant, Rivulet and Syke
The study of streams and waterways in general is known as surface hydrology and is important in environmental geography or environmental geology.
~ In the confrontation between the stream and the rock, the stream always wins, not through strength but by perseverance. ~ H. Jackson Brown, Jr.