In geomorphology, what does 'valley' refer to in terms of elevation?

In geomorphology, the term 'valley' is used to describe a low area of land that has been formed by various natural processes, primarily erosion caused by rivers or glaciers. Valleys are characterized by a downward slope, which directs water runoff and sediment flow toward lower elevation areas. This is critical in understanding how landscapes develop over time, as valleys often serve as drainage systems that guide water towards rivers, lakes, and oceans.

The concept of elevation is key here; valleys are defined by their lower elevation compared to the surrounding terrain. This configuration facilitates the natural gradient where gravitational forces help materials move from higher to lower elevation, reflecting the dynamic processes that shape the earth's surface. Hence, a valley represents a geological feature that points downhill toward lower elevation numbers, supporting the conclusion that valleys are essential in understanding geomorphological landscapes.