ABSTRACT
The landscape of the earth’s surface is largely the creation of two sets of natural forces which act constantly against one another. On the one hand, the apparently solid surface of the earth is little more than a thin crust overlying a molten interior. On the other hand, arrayed against these internal forces of rock and landform creation are the external forces of weather, water, ice and sea which modify and destroy those rocks and landforms. All denudational landscapes can be viewed as the result of the interaction between denudational processes and the underlying geological structure and the time during which that interaction has been taking place. The denudational processes within three basic climatic environments: humid landscapes—where running water is available at all times; arid and semiarid landscapes—where rainfall is very low and running water is available only intermittently; glacial and periglacial landscapes—where temperatures are sufficiently low to maintain water as ice for much of the time.
