

Figure 6. Diagram showing the main components of the hydrologic cycle, including evaporation, transpiration, precipitation, runoff, infiltration, and groundwater runout.
Source: Michael Arthur and Demian Saffer
Instructions
Answer each question in 2-3 complete sentences. Consider each question carefully and be sure to provide a complete answer.
Questions
- What are the outputs and inputs of water from the oceans, as shown in the figure above? Do the same for the continents.
- Do the fluxes to and from the oceans balance? What about the continents?
- Take the total precipitation that falls on the continents from the numbers in the figure above. Calculate the annual average precipitation you would expect, in meters per year, if the precipitation fell evenly over the continents, assuming a total land area of 148 million km2 for the Earth. (Note: be careful with your units here! The values in the figure are reported in 103 km3.)
- How does your precipitation value compare to the mean annual precipitation in Sacramento, CA. How about to State College, PA?
- Do you think the average annual precipitation you calculated above would be enough to allow dry land farming (i.e. without irrigation) or to support major population centers? Explain your reasoning.
Worksheet
Download the worksheet to use when submitting your assessment.
Submitting your Answers
Bring your written answers to class. If they are hand-written, be sure your writing is legible. If your handwriting is not clear, please type and print your answers.
Scoring and Rubric
Each answer will earn a maximum of 5 points for a total of 25 points, as described in the rubric below.
Work Shown | Points Possible |
---|---|
Answer reflects careful consideration of the question | 2 |
Answer is appropriate in length | 1 |
Answer is legible | 1 |
Answer given in complete sentences, correct spelling and grammar | 1 |