A Look at Kings Creek Geomorphology

To understand a creek, we must know something about its geomorphology.  The length, shape and depth are not the only defining characteristics.  How the creek changes over time is an important part of its character.  There are short-term changes, which can be measured by water depth and water’s edge.  These changes are important in an intermittent stream like Kings Creek.  Because the stream is basically spring-fed, and the springs do not always flow at the same rate or maybe do not flow at all, the creek can be low or even dry in periods of drought.  During periods of heavy rainfall or when the soil is already saturated, overland flow can cause flash flooding or high-water events.  These events can change the morphology of the creek in a matter of minutes by scouring the stream bed, moving gravel bars, uprooting trees, and carrying logs and other debris up over banks.  The stream channel can change drastically during high flow events causing the meander or winding course of the stream to look very different.

There are also long-term changes, which can be measured by setting up permanent points or markers from which measurements are taken to show changes in the banks or width of the channel and the depth of gravel bars.  All of these measurements must be taken in a consistent way with a defined method so that data from each year (or other time interval) can be compared to data from other years (or time intervals). 

A stream is also made up of the soil and rocks or gravel carried in its flow, the plants and animals that live in and around it and the organic matter and nutrients dissolved in the water.  In order to understand these living and non-living components, we might also need information on weather conditions and the land use patterns surrounding the stream.    

A stream flows downhill due to gravity and is picking up pieces of its surroundings (erosion), carrying them downstream (transport) and when it slows down, particles drop out of the water to the streambed (deposition).  These geological processes and the living inhabitants are influenced by the speed of the moving water or its current or velocity.

While the stream itself may be considered an ecosystem, the riffles and pools are specific habitats.  A riffle is a more shallow part of the stream where water bubbles or flows over rocks or gravel and picks up oxygen from the air.  A pool is deeper water with a smooth surface and slower current.  Riffles and pools may alternate down the course of the stream.  The deepest part of the stream through any riffle or pool is called the thaweg.  It is not necessarily the center of the stream.

Below is an example of a bird’s-eye view of how a part of Kings Creek meanders or changes over time.  Between August 6, 2004 and September 9, 2004, there was a high-water event that changed the stream in a measurable way.

To enter data from your class visit, click on the icon at the bottom of this page called

"Student Data Input." Your teacher will have the password.

Click on "Kings Creek Data" icon at the bottom of this page for more details about this stream.