Unit 4 — Water on Earth
Description
Students investigate the distribution of water on Earth by researching where freshwater and saltwater are found in oceans, rivers, lakes, glaciers, groundwater, and polar ice caps. They organize their findings into graphs and charts showing the amounts and percentages of water in various reservoirs. Through this analysis, students discover that nearly all of Earth's available water is in the ocean and that most freshwater is frozen in glaciers or stored underground, with only a tiny fraction in streams, lakes, wetlands, and the atmosphere. In the second part of the unit, students research how human activities affect water resources and gather information about ways individual communities use science ideas to protect Earth's freshwater and marine environments. They prepare presentations explaining one community strategy for minimizing the effects of human activities on water resources.
Essential Questions
- Where is water found on Earth and how much is freshwater?
- How do individual communities use science ideas to protect Earth's water resources and environment?
Learning Objectives
- Describe physical quantities such as weight and volume using standard units
- Describe and graph the amounts and percentages of water and freshwater in various reservoirs
- Provide evidence about the distribution of water on Earth based on graphed data
- Describe a system in terms of its components and their interactions
- Obtain and combine information from books and reliable media about how communities protect Earth's resources
- Understand that science findings are limited to questions that can be answered with empirical evidence
Supplemental Resources
- Markers for creating labeled graphs and charts of water distribution for data visualization
- Chart paper for displaying water distribution percentages and amounts for presentations
- Highlighters for marking key information in research materials for note-taking
- Index cards for organizing information about community water protection strategies for research organization
- Colored pencils for creating detailed maps showing water reservoirs for geographic representation
Crosscutting Concepts
Disciplinary Core Ideas
Science and Engineering Practices
Students use informational texts and digital sources to conduct research, gather evidence, and build knowledge across all science units. They quote accurately from texts, draw inferences, summarize and paraphrase information in science notebooks, write opinion pieces supporting claims with evidence, and incorporate multimedia components into presentations. Reading informational texts and writing research-based explanations are explicitly aligned to science performance expectations throughout all six units.
Students apply mathematical reasoning and computational thinking across all units. They measure and graph physical quantities such as weight, volume, and temperature; use coordinate plane graphing to represent scientific data; convert measurement units within standard systems; and reason abstractly and quantitatively when analyzing data as evidence for scientific explanations. Mathematical practices including modeling with mathematics and using appropriate tools strategically are integrated throughout investigation and data analysis activities.
Formative Assessments
- Students use informational texts and online resources to gather data about water distribution on Earth
- Students create graphs and charts showing freshwater and saltwater distribution across reservoirs
- Students analyze and compare data to identify patterns in water distribution
- Students gather information from multiple sources about human impacts on water and community protection strategies
Summative Assessment
Students create a special TV news report that addresses the importance of freshwater on Earth and strategies for protection.
Benchmark Assessment
— not configured —
Alternative Assessment
Students may demonstrate understanding through a teacher-led data interpretation discussion using pre-made graphs and charts, or by sorting picture cards and labels representing different water reservoirs instead of creating original graphs. Visual supports such as labeled diagrams of water distribution and word banks may be provided to support responses about freshwater locations and human protection strategies.
IEP (Individualized Education Program)
Students benefit from scaffolded data collection tools, such as partially completed graphic organizers or charts with labeled headings, to help them organize information about water distribution across Earth's reservoirs. Teachers should provide access to audio or read-aloud versions of informational texts and allow students to demonstrate understanding through oral explanations or dictated responses rather than written summaries alone. Visual supports such as labeled diagrams, color-coded charts, and annotated maps of water reservoirs can reduce processing demands while keeping students engaged with grade-level science content. For the summative presentation, consider allowing students to contribute through a recorded segment, illustrated poster, or verbally narrated slide rather than a fully written script.
Section 504
Students should be given extended time when gathering and analyzing data from multiple sources about water distribution and human impacts on water resources. Preferential seating near instructional displays and access to a distraction-reduced environment during research and graphing tasks will support sustained focus. Printed copies of any data sets, charts, or source materials displayed digitally should be made available so students can reference and annotate at their own pace.
ELL / MLL
Teachers should provide visual supports such as labeled maps, diagrams of Earth's water reservoirs, and picture-supported vocabulary cards for key science terms including reservoir, glacier, groundwater, freshwater, and saltwater. Directions for research and graphing tasks should be given in short, clear steps and checked for understanding before students begin working independently. When possible, allow students to preview content in their home language and encourage them to use bilingual resources or translation tools to build background knowledge before engaging with English-language source materials.
At Risk (RTI)
Students who need additional support should begin with simplified data sets that highlight the most essential comparisons, such as the difference between total ocean water and available freshwater, before working with more complex multi-reservoir breakdowns. Connecting the content to familiar local water sources or community water use helps build meaningful entry points into the broader concepts of water distribution and conservation. Breaking the research and graphing process into structured, sequential steps with frequent check-ins allows students to build confidence and maintain progress toward the summative presentation.
Gifted & Talented
Students ready for greater depth should explore the quantitative relationships between water reservoirs more rigorously, such as by calculating percentage changes over time using real hydrological data sets or examining how climate variability affects the distribution of freshwater across regions. Extending into the human impact portion of the unit, these students can investigate the policy, economic, and equity dimensions of water resource management across different communities or countries, drawing on sources beyond the classroom. Their summative presentation might take on the form of a data-driven investigative report that proposes and defends an original community strategy using evidence from multiple scientific and civic sources.