a group of rivers that eventually join together as one

She starts out where the stream valley is low and wide and the gradient is gentle so the hiking is easy. Imagine a hiker following a stream up to its beginning and tracking her progress on a topographic map. A dendritic drainage pattern is the most common type.Ī graded profile starts with a steep slope at the beginning of the stream and tapers to a gentle slope at the base level of the stream. If the geology underlying a stream system is fairly uniform-rocks equally resistant to erosion in all directions-a dendritic drainage pattern will develop, as shown in figure 1. Some types of rock are harder and more resistant to erosion than others. The drainage pattern depends on the rock types and geologic structures underlying the stream system. Drainage PatternsĪ stream system that includes multiple tributaries exhibits a distinct drainage pattern as seen on a map. When flooding occurs, higher order streams take longer to build up to flood stage than lower order streams and longer for the flood to subside. As more and more tributaries join together a larger stream network is formed and the master stream, the highest order stream in the system has a discharge that is the sum of all the tributary discharges. The Mississippi River is a tenth order stream, one of the highest order streams on earth. A stream that has any second-order tributaries and none higher is a third-order stream, and so on. A stream with only first-order tributaries is a second order stream. A stream with no tributaries is a first order stream. The smaller of the two streams is a tributary of the larger stream. It is common for one stream to flow into another. What stream drainage do you live in? Stream Order Boundaries between stream drainage areas are called drainage divides. A stream drainage area is also called a watershed.

The drainage area of a stream encompasses all the land from which surface runoff flows into that 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. The higher the hill, the more gravitational energy there is to drive the stream. Streams flow downhill due to the force of gravity. Streams erode dirt and rocks, transport the sediment, and redeposit it in new locations, shaping the earth’s surface into a system of stream valleys. Most valleys on earth are the product of streams. Over longer intervals of time the same processes we’ve imagined on the construction site have built systems of streams and stream valleys on the surface of the earth. If not prevented, the channels may continue to deepen and erode soil from the construction site.

A network of streams, including tributaries, has formed. Soon, the water excavates small channels, known as rills, in the dirt. At first the water saturates the ground and begins to flow downhill across the surface of the slope in a thin sheet. It is interesting to watch water on a recently bulldozed construction site with a slope. A small brook in a meadow and the Amazon River are both streams. What Are Streams?Ī stream is flow of water, driven by gravity, in a natural channel, on land. 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. Streams sculpt and shape the earth’s surface by eroding, transporting, and depositing sediment.

A group of rivers that eventually join together as one