A course on the environment of the Earth’s surface would be seriously incomplete without a chapter on the Earth’s landscapes. An early chapter dealt with practical matters of describing the lay of the land by means of topographic maps. Now is the time to give attention to nature and origin of the Earth’s landforms and landscapes.
Everybody knows about landscapes. Dictionaries define a landscape as the aggregate of surface topographic features in some region as produced or modified by geologic processes, or as a region of the Earth’s surface that the eye can see in a single view. A land form is some topographic feature of the Earth’s surface that originated by natural processes. You can think of a landscape as consisting of a number of individual landforms, of various kinds, in some definite relationship one to another. Hills, mountains, and valleys—of which there are many kinds—are examples of landforms. You have already learned much about specific landforms, in the earlier chapters on rivers and glaciers. Now is the time to have a more systematic look at the Earth’s major landforms.
The study of landforms is a matter dealt with in the science of geomorphology (the study of the Earth’s landscapes and the processes that shape them), a branch of Earth science that has been around since early in the modern age of Earth science, in the nineteenth century. Geomorphologists view themselves in part as geologists and in part as geographers. In the US, geomorphologists have tended to be geologists, whereas in the British sphere they have tended to be geographers. (Turf distinctions, although to a large extent artificial, have always been with science, as is true of many other fields as well.)
There is a longstanding dichotomy in geomorphology between the study of the history of development of landscapes, on the one hand, and the study of natural processes that shape the Earth’s surface. The latter is usually referred to as “process geomorphology”, and has been alive and well in recent decades. We have done quite a lot of it in this course. The former, however, which was first systematically developed by the preeminent early geomorphologist William Morris Davis (1850–1934) has had a checkered history.
The plan of this chapter is first to deal with classical Davisian geomorphology, along with some alternatives, and then to look at some of the prominent landscape elements that develop in areas of the Earth’s surface—and they constitute much the greater part of the Earth’s surface—where fluvial processes dominate. First, however, the following section presents some initial material on mountains and valleys.