Simply put, Geomorphology is the science of landforms. It is the science that provides with a closer look at the Earth's surface and the processes that have formed them. Although Geomorphology is concerned with landforms that currently exist, past landforms and events must be examined in order to fully understand how they came about.
Although the term Geomorphology is a relatively new term (1880's), the examination of the forces of nature that have impacted the Earth's surface extends back into the days of early Greek and Roman philosophers such as Aristotle and Seneca. Their writings included ideas on stream erosion, earthquakes and other deformations. Though these early philosophers speculated on the ideas of landscape evolution, these processes and thoughts were not fully examined until just before the 1800's.
In 1785, James Hutton began to develop on ideas on the formation of the surface. He argued that the surfaces were formed by slow, but continuous erosive processes instead of great catastrophic events as others have thought. From Hutton's work, came Charles Lyell's principles of Uniformitarianism. These 4 principles are:
Uniformity of Law- it is assumed that natural laws are a constant.
Uniformity of Process- this is essentially the rule of simplicity. If an event can be explained by past events, then no new "unknown causes" should be introduced.
Uniformity of Rate- refers to the idea that the processes the shape the surface are slow and steady.
Uniformity of State- the Earth has always reacted much the same as it does today.
In response to Lyell's principles of Uniformitarianism came catastrophism. Catastrophism was the ideas that the Earth's surface was not changed by slow, gradual events, but rather by rapidly occurring catastrophic events.
John Wesley Powell, a pioneer of geologic studies in North America, made several new contributions to the field. He studied the American West and developed classifications for mountains, valleys and drainage systems as well. Perhaps the most popular of his concepts is that of base level. Base level is the lowest extent to which a river can cut, essentially sea-level. A colleuge of Powell, Grove Karl Gilbert, made the next great contribution known as the laws of the landscape.
William Morris Davis developed new theories called the cycle of erosion. In these theories, Davis classified landforms into one of three categories. These are known as youth, maturity and old age. The category was determined by how long an erosional process has been in effect. It should be noted that his categorical descriptions are rather general. Also, many geomorphologists acknowledge a fourth category referred to as rejuvenated landscape.