Table 1 Constructed response questions.

Sources of FEW & Connections: Reservoir

(a) A reservoir like the one pictured above is an artificial lake that stores water. What types of energy does the water in this reservoir possess?

(b) Explain how the kinds of energy listed in your previous response could be used for food production by nearby farmers.

These responses tell us:

(1) What students understand

about how water can create energy

(2) The linkages students explain between water, energy, and food resources

Trade-offs of FEW systems: biomass energy production

Biomass energy production involves growing certain crops and converting them to energy. Corn, in the form of ethanol, is a common source of biomass energy. To increase its energy independence from natural gas, your community decides to convert half of their existing agricultural bean fields to corn biomass crops that will eventually provide energy to the surrounding area. You have taken an environmental course and know that burning natural gas has a greater energy return than burning biomass (e.g., one unit of natural gas requires less energy to produce than one unit of ethanol biomass).

(a) You realize that corn requires more water to produce than beans; much of your irrigation water comes from a nearby river and limited rainfall. How would you expect the area’s water use to change as a result of this shift from agriculture to biomass production?

(b) Trade-offs describe the compromise between positive and negative outcomes of a decision. A trade-off results in something decreasing in return for gains in something else. Describe the trade-offs to food, energy, and water systems in switching from bean farming to biomass (corn) farming

These responses tell us:

(1) Student capacity to evaluate predictions based on their analysis of cause and effect relationships

(2) Student capacity to understand trade-offs in connection to their analysis and evaluation of cause and effect relationships