Davis Cycle Diagram Interpretation

In graphical illustrations of William Morris Davis's geographical cycle model, diagrams often depict the evolution of a landscape over time. These diagrams typically include two curves:

• The upper curve generally represents the initial maximum elevation or height of the landmass.
• The lower curve typically represents the base level of erosion, which is the theoretical limit to which land can be lowered by erosion.

The vertical distance or gap between these two curves at any given stage illustrates the difference between the highest points of the landmass and the base level. This difference directly corresponds to the amount of vertical land dissection remaining above the base level, which is precisely the definition of relative relief. As the geographical cycle progresses, erosion reduces the land's height relative to the base level, thus decreasing this gap.