Quiz & test questions Grade 11 Science
Kellsworth Basin Water Cycle: A Watershed Budget Unit Test
A grade 11 unit test on the water cycle and a fictional watershed's budget, mixing multiple-choice, short-answer, and computation items on flows, storage, and recharge.
Objectives
- Students will describe the processes and reservoirs of the water cycle, including residence times.
- Students will solve a watershed water budget for the change in storage and interpret it.
Vocabulary
- Water cycle
- The water cycle is the continuous movement of water between the oceans, the air, and the land. The same water evaporates, forms clouds, falls as rain or snow, and flows back to the ocean before the process repeats.
- Evapotranspiration
- Evapotranspiration is the total amount of water that leaves the land and goes into the air, both from wet surfaces and from plants. Scientists combine evaporation and transpiration into one word.
- Infiltration
- Infiltration is when rain or melted snow soaks down into the soil instead of flowing away across the top of it. Water that infiltrates can feed plant roots or keep sinking to become groundwater.
- Water budget
- A water budget is a way of tracking all the water coming into an area, like rain and snowmelt, against all the water leaving it, like evaporation and streamflow. Scientists use water budgets to see whether a watershed or aquifer is gaining or losing water over time.
- Residence time
- Residence time is how long a drop of water typically stays in one part of the water cycle before moving on. Water passes through the air quickly but can stay underground for a very long time.
- Recharge
- Recharge is water soaking down through the ground to refill an aquifer, the way rain refills an underground sponge. Aquifers stay healthy only if recharge keeps up with pumping.
Also: runoff
Teacher overview
This 40-minute unit test (30 points total) checks whether students can describe the water cycle and its reservoirs and can balance a watershed water budget. It mixes three multiple-choice items, five short-answer items, and two computation items built around a fictional basin. The computation items need no outside data; a student needs only the numbers stated in the test.
Assessment
(2 points) About what percent of Earth's water is held in the oceans?
- A) 50 percent
- B) 71 percent
- C) 97 percent
- D) 2 percent
(2 points) On average, water spends about 9 days in the atmosphere but centuries to millennia in deep groundwater. Which choice lists these two reservoirs in order from the shortest average residence time to the longest?
- A) deep groundwater, then the atmosphere
- B) the atmosphere, then deep groundwater
- C) they are about equal
- D) it cannot be determined
(3 points) Name the single term for water moving from soil and plants into the atmosphere, and describe one condition that increases it.
(3 points) Explain the difference between infiltration and runoff, and name one land-use change that shifts rainfall from infiltration toward runoff.
(4 points) In the fictional Kellsworth Basin, one year brings 40 inches of precipitation. Of that, 26 inches leave as evapotranspiration and 10 inches leave as runoff. Using the water budget precipitation = evapotranspiration + runoff + change in storage, find the change in storage, in inches.
(3 points) Using the Kellsworth numbers from item 5, what percent of the precipitation leaves the basin as runoff?
(3 points) The change in storage from item 5 recharges the basin's aquifer. Explain why a multiyear drought, with lower precipitation, can shrink that recharge even if evapotranspiration stays about the same.
(3 points) Which statement best uses the idea of residence time?
- A) A contaminant reaching deep groundwater may persist for centuries because water moves through it very slowly.
- B) Groundwater refreshes within days, so contamination clears quickly.
- C) Residence time describes how salty the ocean is.
- D) Residence time only applies to the atmosphere.
(4 points) A warming atmosphere changes the water cycle. Using what published climate models show, describe two ways a warmer atmosphere can change precipitation or storage in a basin.
(3 points) Explain why less than 1 percent of Earth's water is readily available as fresh water, referring to where most of the planet's water is held.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
Answer: C) 97 percent. About 97 percent of Earth's water is in the oceans, which is why it is salty and not directly drinkable.
Answer: B) the atmosphere, then deep groundwater. Water spends about 9 days in the atmosphere on average but centuries to millennia in deep groundwater, so the atmosphere has the shorter residence time.
Answer: Evapotranspiration. Accept any one increasing condition, such as higher temperature, more sunlight, lower humidity, or more wind, each of which speeds evaporation and transpiration.
Answer: Infiltration is water soaking down into the soil, while runoff is water flowing across the surface into streams. Accept any land-use change that seals the surface, such as paving, building, or compacting soil, which shifts rain from infiltration toward runoff.
Answer: 4 inches. Rearranging the budget, change in storage = precipitation - evapotranspiration - runoff = 40 - 26 - 10 = 4 inches of storage gained, which recharges the aquifer.
Answer: 25 percent. Runoff is 10 inches out of 40 inches of precipitation: 10 / 40 = 0.25, or 25 percent.
Answer: In a drought, less precipitation comes in, but evapotranspiration and runoff still claim their share of what does fall. With those outflows nearly unchanged, less water is left over for storage, so the recharge (change in storage) shrinks or can even go negative.
Answer: A) A contaminant reaching deep groundwater may persist for centuries because water moves through it very slowly. Long residence time means slow flushing, so pollution underground can last for generations.
Answer: Accept any two supported by climate-model results, such as heavier, more intense storms that produce more runoff and less infiltration; higher evaporation that dries soils and lowers storage; or less snowpack and earlier melt that shifts the timing of streamflow.
Answer: Almost all of Earth's water is either salty or frozen. About 97 percent is salty ocean water, and roughly 2 percent is frozen in ice caps and glaciers, leaving less than 1 percent as accessible liquid fresh water in lakes, rivers, and reachable groundwater.
Differentiation
Support
Provide a labeled water-cycle diagram and the water-budget equation with each term named, and give item 5 with the equation already arranged to solve for the change in storage. Allow a calculator on items 5 and 6.
Extension
Have students extend item 5 by converting the 4 inches of recharge over a stated basin area into a volume in acre-feet, and explain why planners prefer a volume over a depth when comparing basins of different sizes.
ELL supports
Provide a word bank (evapotranspiration, infiltration, runoff, recharge, residence time) with a small icon for each, and allow short-answer items 3, 4, 7, and 10 to be answered with a labeled diagram plus a short sentence from a provided frame.