ABSTRACT
One of the many definitions for scale in Webster’s dictionary is a system of grouping or classifying in a series of steps or degrees according to a standard of relative size, amount, importance, perfection, etc. The jargon used to describe scales in earth science includes, for example, continuum, correlation, integral, microscopic, macroscopic, local spatial average, REA (representative elementary area), and REV (representative elementary volume). The objective of this chapter is to introduce the subject of scale as it relates to hydrology, the entirety of which could easily fill several volumes.
