As described in class and text (pp. 237-240 and 247-256), the hydrologic cycle or "water budget" is conceptually pretty simple: evaporation (E) from oceans and other surface water puts water vapor in the air, it gets moved by atmospheric circulation and condenses and falls as precipitation (P) that can either runoff (R), get intercepted and stored (on vegetation, in lakes, etc.), perhaps re-evaporated to the atmosphere from the ground and transpired from vegetation (ET), or infiltrates (I) or soaking into the soil to become groundwater.

The basic water budget of a place is something like this: P = R + I + ET

Or you can think of it as R = P - (I+ET)

OK, but humans intervene in this cycle in dozens of ways at various points, affecting the amounts and the quality of flows and stages in the cycle. This diagram from the Colorado Division of Water Resources illustrates some of those ways.

From: Colorado Department of Water Resources.

Student name:___________________________

ss#:___________________________

TA name:___________________________

Your exercise is to develop a list of purposeful and inadvertent human transformations of the water cycle, identifying for each: (a) the human intervention and (b) how it tends to affect the relevant component of the water cycle (P, ET, I, R).

Purposeful

Inadvertent

Purposeful

Inadvertent

Purposeful

Inadvertent

Purposeful

Inadvertent