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Quiz & test questions Grade 9 Science

Water Cycle and Watersheds: A Grade 9 Earth Systems Test

A 25-point grade 9 assessment on the water cycle and watersheds, mixing multiple-choice, short-answer, and one runoff computation item on Earth's connected systems.

Objectives

  1. Students will identify processes and storage reservoirs in the water cycle.
  2. Students will explain how land use in a watershed changes runoff and infiltration.
  3. Students will calculate roof runoff from area and rainfall.

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.
Watershed
A watershed is all the land where rain that falls will drain to the same stream, river, or lake. Everyone lives in a watershed, no matter how far from the water they live.
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.
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.

Also: runoff

Teacher overview

This 30-minute assessment is worth 25 points and checks how well students understand the water cycle and watersheds as connected Earth systems. It mixes four multiple-choice items, four short-answer items, and one runoff computation. The items move from recalling processes and storage in the water cycle to explaining how a change to the land feeds back on the movement of water.

Water Cycle and Watersheds: A Grade 9 Earth Systems Test — Grade 9 Science
Name: ____________________________ Date: ______________

Assessment

  1. (2 points) Which process moves water from the surface into the air as water vapor?
    • A) condensation
    • B) evaporation
    • C) infiltration
    • D) runoff
  2. (2 points) About what share of Earth's water is accessible fresh water?
    • A) about 97 percent
    • B) about 30 percent
    • C) about 10 percent
    • D) less than 1 percent
  3. (2 points) On average, water spends about 9 days in which part of the water cycle?
    • A) the ocean
    • B) deep groundwater
    • C) the atmosphere
    • D) glaciers
  4. (3 points) Define a watershed in your own words, and name one way that land use inside a watershed can affect the stream at its outlet.
  5. (4 points) A town clears a forested hillside and covers much of it with houses and pavement. Explain how removing the trees and adding pavement changes runoff and infiltration, and give one effect this could have downstream.
  6. (4 points) The fictional town of Millbrook wants to estimate roof runoff. A school roof is 5,000 square feet. In one storm it receives 1.5 inches of rain. Using 0.623 gallons of runoff per square foot per inch of rain, calculate how many gallons run off the roof. Show your work.
  7. (3 points) Explain why deep groundwater is considered long-term storage in the water cycle, compared with the water in a river.
  8. (3 points) Give one reason the availability of fresh water shaped where an early city was built, and explain the connection.
  9. (2 points) Increasing the amount of pavement in a watershed most directly causes which change?
    • A) more infiltration and less runoff
    • B) faster and greater runoff and less infiltration
    • C) no change to runoff
    • D) more groundwater recharge

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key
  1. Answer: B) evaporation.
    Evaporation moves liquid water from the surface into the air as vapor. Condensation is the reverse, and infiltration and runoff move water across or into the land, not into the air.
  2. Answer: D) less than 1 percent.
    Most of Earth's water is in the oceans (about 97 percent), and much of the fresh water is frozen, so less than 1 percent is accessible fresh water.
  3. Answer: C) the atmosphere.
    Water spends about 9 days on average in the atmosphere, a short residence time compared with groundwater or glaciers.
  4. Answer: A watershed is the land area that drains to a common stream or river; land use inside it affects the outlet.
    Accept any clear definition of a watershed as the area of land draining to one point, plus one land-use effect such as farming, pavement, or clearing adding runoff or pollutants to the stream.
  5. Answer: Less infiltration and more runoff, with a downstream effect such as flooding or erosion.
    Trees and soil normally let rain soak in (infiltration). Removing them and adding pavement blocks soaking, so more rain runs off quickly. Accept one downstream effect such as faster flooding, more erosion, or more sediment and pollutants reaching the stream.
  6. Answer: 4,672.5 gallons.
    Runoff = 5,000 square feet x 1.5 inches x 0.623 gallons per square foot per inch = 7,500 x 0.623 = 4,672.5 gallons.
  7. Answer: Water can remain in deep groundwater for centuries to millennia, far longer than in a river.
    River water moves through in weeks to months, while water in deep groundwater can stay for centuries to thousands of years, so groundwater acts as long-term storage in the water cycle.
  8. Answer: Early cities grew near reliable fresh water for drinking, farming, and transport.
    Accept any reasoned answer, such as a city built beside a river because the water supplied drinking water, irrigation for crops, and a route for boats, so the resource drew people to settle there.
  9. Answer: B) faster and greater runoff and less infiltration.
    Pavement is impervious, so rain cannot soak in. That sends more water running off faster and reduces how much soaks into the ground.

Differentiation

Support

Allow students to use a labeled water-cycle diagram during the multiple-choice items, and provide the runoff formula for item 6 already written with labeled blanks for area, rainfall, and the 0.623 factor.

Extension

Ask students to extend item 6 by finding how many gallons would run off the same roof in a 2.5-inch storm, then explain why runoff scales directly with rainfall depth.

ELL supports

Pre-teach "watershed," "infiltration," and "runoff" with paired images and short definitions. Provide sentence frames for items 4 and 5, such as "A watershed is ___," and "Adding pavement causes ___ because ___."