Lab 1: Where's the Water?
The lab activity described here was created by Betsy Youngman of Phoenix Country Day School and LuAnn Dahlman of TERC for the EarthLabs project.
Summary and Learning Objectives
Using data on the world's water distribution, students calculate the percentage of water that is available to humans and examine graphics that illustrate the distribution. Students develop a sense of where the world's water is located and how it moves through the Earth system.After completing this investigation, students will be able to:
- Interpret graphics of world water consumption and distribution.
- Use data to calculate percentages of water distribution.
- Translate data into a hands-on demonstration (an optional task).
- Interpret maps, charts, and other info-graphics.
Context for Use
This is the introductory lab in a sequence of lessons on drought: it sets the tone of the topic's importance for subsequent lessons. The lesson has a section that requires calculation of percentages; these can be solved with a calculator or spreadsheet program. The activity can be completed individually, in small groups, or as a whole class. The entire lesson should take 1-2 class periods.
Estimated Time Required:
Part A: 30 minutes
Part B: 15 minutes
Part C: 30 minutes
Activity Overview and Teaching Materials
In Part A, Students begin their study of drought by reading a statement from the World Water Council about the importance of water to life. They also examine a unique cartogram that depicts water consumption around the world. Provided with a table of data on global water distribution, students use a spreadsheet program or a calculator to learn what a small portion of the world's water is readily available for human use. Part A also suggests an optional hands-on activity to kinesthetically reinforce the relative lack of freely available freshwater resources.
In Part B, students consider the quantity of water that moves through hydrologic cycle and approximate residence times that it spends in each step of the cycle.
In Part C, students explore the concept of freshwater and population distribution, raising the issue of water scarcity. The lab concludes with students exploring a report and Website published by the journal, Scientific American.
You may want to provide a hard copy of the activity sheet (Acrobat (PDF) 27kB Aug3 08) on which students can record their answers. A
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Teaching Notes and Tips
The importance of freshwater to survival, as well as its relative scarcity, are the most important points of this lab. You might heighten student interest in this topic by giving this description of a water distribution demonstration (Microsoft Word 94kB Aug3 08) to a pair or small group of your more animated students and assigning them to practice and present the demonstration as a 5-minute follow up to the lab.
The calculate section could be assigned for completion without a calculator as a way to encourage students to practice using their manual quantitative skills.
Graphics about the global availability of freshwater at Vital Water Graphics, United Nations Environment Programme may be useful for stimulating follow-up discussions or for assessing student understanding.
As an alternate assessment, students can make their own info-graphics to share with the class. Students can choose from amongst the issues raised in this lesson.
Challenging students to come up with a creative illustration for the optional hands-on demonstration would also make an excellent performance assessment. Here is one set of detailed instructions for this demonstration.
State and National Science Teaching Standards
Applicable California Science Teaching Standards
Earth Science - Biogeochemical Cycles
7c. Students know the movement of matter among reservoirs is driven by Earth's internal and external sources of energy.
g. Recognize the usefulness and limitations of models and theories as scientific representations of reality.
Applicable Massachusetts Science and Technology Standards (PDF - 1.3 Mb)
Earth and Space Science - Energy in the Earth System
- 3.5 The hydrologic cycle includes evaporation, condensation, precipitation, surface runoff and groundwater percolation, infiltration, and transpiration.
Applicable New York Core Curricula
Physical Setting/Earth Science (PDF - 135 Kb)
- STANDARD 4 – Students will understand and apply scientific concepts, principles, and theories pertaining to the physical setting and living environment and recognize the historical development of ideas in science.
- Key Idea 2: Many of the phenomena that we observe on Earth involve interactions among components of air, water, and land.
- STANDARD 6 — Interconnectedness: Common Themes. Students will understand the relationships and common themes that connect mathematics, science, and technology and apply the themes to these and other areas of learning.
- Key Idea 2. Models are simplified representations of objects, structures, or systems used in analysis, explanation, interpretation, or design.
Applicable North Carolina Earth and Space Science Standards4.04 Evaluate water resources: Environmental impacts of a growing human population.affects the amount and quality of
Applicable Texas Essential Knowledge and Skills (TEKS)None identified
Applicable National Science Education Standards (SRI)
Earth and Space Science (12DESS)
- Geochemical cycles 12DESS2.2 Movement of matter between reservoirs is driven by the earth's internal and external sources of energy. These movements are often accompanied by a change in the physical and chemical properties of the matter. Carbon, for example, occurs in carbonate rocks such as limestone, in the atmosphere as carbon dioxide gas, in water as dissolved carbon dioxide, and in all organisms as complex molecules that control the chemistry of life.
Science in Personal and Social Perspectives (12FSPSP)Natural Resources
- 12FSPSP3.1 Human populations use resources in the environment in order to maintain and improve their existence. Natural resources have been and will continue to be used to maintain human populations.
- 12FSPSP3.2 The earth does not have infinite resources; increasing human consumption places severe stress on the natural processes that renew some resources, and it depletes those resources that cannot be renewed.
- 12FSPSP3.3 Humans use many natural systems as resources. Natural systems have the capacity to reuse waste, but that capacity is limited. Natural systems can change to an extent that exceeds the limits of organisms to adapt naturally or humans to adapt technologically.
- 12FSPSP4.3 Many factors influence environmental quality. Factors that students might investigate include population growth, resource use, population distribution, overconsumption, the capacity of technology to solve problems, poverty, the role of economic, political, and religious views, and different ways human s view the earth.
- 12FSPSP5.4 Natural and human induced hazards present the need for humans to assess potential danger and risk. Many changes in the environment designed by humans bring benefits to society, as well as cause risks. Students should understand the costs and tradeoffs of various hazards — ranging from those with minor risk to a few people to major catastrophes with major risk to many people. The scale of events and the accuracy with which scientists and engineers can (and cannot) predict events are important considerations.
- USGS water science for schools
- EPA water
- Groundwater Foundation
- Vision Learning Hydrological cycle
- Circle of Blue
This lesson presents numerically intensive information in a range of ways that can resonate with different learning modalities. Using a variety of presentation styles can make the information more accessible to diverse learners.
Once students begin to see the collision of water resources availability and population distribution and growth, they may want to share news articles. Engaging students in discussions on current events related to drought would be a powerful addition to this lesson.