What are the principal components of a landscape? A landscape is described in terms of topography, which includes elevation, the vertical distance above or below sea level, and relief, the difference between the highest and the lowest elevations in a region. A landscape comprises the varied landforms produced through erosion and sedimentation by streams, glaciers, mass wasting, and the wind. The most common landforms are mountains and hills, plateaus, and structurally controlled cliffs and ridges—all of which are produced by tectonic activity modified by erosion.
How do the climate and plate tectonic systems interact to control landscapes? Landscapes are shaped by plate tectonic processes, weathering, erosion, and resistance to erosion. Plate tectonic processes lift up mountains and expose rock. Erosion carves rock into valleys and slopes. Climate, in turn, affects rates of weathering and erosion. Variations in climate and bedrock type strongly modify landscape development, making desert and glacial landscapes very different.
How do landscapes develop? The development of landscapes depends strongly on competition between the forces of uplift and the forces of erosion. Landscapes begin their development with tectonic uplift, which in turn stimulates erosion. When tectonic uplift rates are high, erosion rates also tend to be high, and mountains are high and steep. As uplift rates decrease, erosion rates remain high; the land surface is lowered and slopes are rounded. When uplift ends, erosion becomes the dominant process and wears down the former mountains to gentle hills and broad plains.