3.1 What do we use water for?

Information for Planning & Teaching

Background Knowledge

Water use distribution can vary significantly between developed and developing countries due to factors such as infrastructure, access to resources, economic development, and population dynamics. Water use in developed countries is distributed differently than in countries that are still developing. This is most obviously seen through the high use of water for agriculture in developing countries and the higher use of water for industry in developed countries.

Developed Countries:

1. Infrastructure and Access: Developed countries generally have well-established water supply and sanitation infrastructure, ensuring reliable access to clean water for most households. They typically have extensive networks of water treatment plants, reservoirs, and distribution systems that deliver water to homes, schools, industries, and other institutions.

2. High Per Capita Water Use: Developed countries tend to have higher per capita water consumption due to factors like larger household sizes, increased water usage in industries, higher standards of living, and access to modern amenities. This can include water-intensive practices like landscaping, swimming pools, and industrial processes.

3. Efficient Water Management: Developed countries often invest in water management practices, technologies, and policies to improve water efficiency and reduce wastage. These can include water metering, pricing mechanisms, public awareness campaigns, and the use of water-saving appliances and fixtures.

4. Advanced Wastewater Treatment: Developed countries typically have advanced wastewater treatment systems to ensure proper sanitation and minimize environmental impacts. These systems remove contaminants from wastewater before it is discharged back into the environment, protecting water bodies and public health.

Developing Countries:

1. Limited Access: Developing countries may face challenges in providing universal access to clean water and sanitation services. Many rural areas and marginalized communities may lack access to safe drinking water, relying on distant water sources or contaminated water supplies.

2. Low Per Capita Water Use: Due to limited access and scarcity, per capita water use in developing countries is generally lower than in developed countries. People often practice water conservation out of necessity, using water sparingly for essential needs such as drinking, cooking, and basic hygiene.

3. Water Source Diversity: In developing countries, water sources can vary greatly, including surface water (rivers, lakes), groundwater, rainwater harvesting, and communal wells. Communities may rely on multiple sources depending on availability, accessibility, and reliability.

4. Challenges in Water Management: Developing countries often face challenges in water management, including inadequate infrastructure, limited financial resources, and institutional capacity constraints. They may struggle to balance competing demands for water, address water scarcity issues, and implement effective governance and regulatory frameworks.

5. Sanitation and Wastewater Treatment: Developing countries may face challenges in wastewater treatment and sanitation infrastructure. Proper sanitation practices and wastewater treatment systems may be lacking in many areas, leading to pollution of water sources and increased health risks.

It is important to note that these descriptions are generalizations, and water use distribution can vary widely within both developed and developing countries. Socioeconomic factors, regional differences, and specific water management practices can significantly influence water use patterns. Understanding these differences helps inform discussions about water scarcity, sustainability, and the need for equitable access to clean water and sanitation services worldwide.

Water sources & Access affected by population increase:

An increase in population can have several effects on water sources and access.

1. Increased Water Demand: As the population grows, the demand for water increases. More people will require water for drinking, sanitation, agriculture, industry, and other daily needs. This increased demand puts pressure on existing water sources, potentially leading to water scarcity and competition for limited water resources.

2. Depletion of Water Sources: Higher population densities can lead to the over-exploitation and depletion of water sources such as rivers, lakes, and aquifers. Increased extraction for agriculture, industrial activities, and domestic use can lower groundwater levels or reduce flow in rivers and streams, negatively affecting water availability.

3. Strain on Infrastructure: A larger population requires adequate water infrastructure to provide clean water and sanitation services. Building and maintaining infrastructure such as water treatment plants, distribution networks, and wastewater treatment facilities can become more challenging and costly with a growing population.

4. Water Pollution and Quality Issues: Population growth can contribute to increased pollution and degradation of water sources. Discharge of untreated wastewater, industrial pollutants, and agricultural runoff can contaminate water bodies, making them unfit for human consumption and ecosystem health. Ensuring access to safe and clean water becomes more complex as the population increases.

5. Disparities in Water Access: Population growth can exacerbate existing disparities in water access. Marginalized communities, informal settlements, or areas with limited infrastructure may struggle to meet the water needs of their growing population. This can lead to unequal access to clean water and sanitation services, further exacerbating social and economic inequalities.

6. Impacts on Ecosystems: Increasing population and associated water demands can have adverse effects on natural ecosystems. Water diversion for agriculture or urban development, habitat destruction, and alteration of water flows can disrupt ecosystems and affect biodiversity, potentially leading to long-term environmental consequences.

Addressing the challenges related to water sources and access in the face of population growth requires comprehensive planning, sustainable water management practices, and investment in infrastructure and technologies. Strategies such as water conservation, efficient agricultural practices, watershed management, water reuse and recycling, and improved governance and policies can help ensure sustainable water resources for present and future populations.

Lesson Timing

This lesson can be implemented flexibly in several different ways. The point of this lesson is for students to gain experience looking at data, drawing a conclusion, and using the data to support their conclusion. Additionally, the data provides more context to learners about water usage across the world. To save time, this lesson can be cut down to a class discussion about water uses and teaching the CER framework without asking students to complete 3.1 Per Capita vs. Total Withdrawal worksheet. Or, if there is a type of argumentation method or approach that is common in your school, it can replace CER.

Student Ideas & Experiences

Science Practices

Argumentation is considered a science practice in the Next Generation Science Standards (NGSS) because it plays a critical role in scientific inquiry and the development of scientific understanding.

1. Constructing Scientific Explanations: Argumentation allows students to construct scientific explanations for phenomena or observations they encounter. By engaging in argumentation, students develop and refine their scientific reasoning and communication skills, supporting claims with evidence and logical reasoning.

2. Evaluating and Communicating Evidence: Through argumentation, students learn to evaluate the quality and relevance of evidence and effectively communicate their ideas to others. They learn to critically analyze data, identify patterns, draw conclusions, and justify their claims based on evidence.

3. Encouraging Critical Thinking: Argumentation promotes critical thinking skills as students consider multiple perspectives, evaluate conflicting evidence or claims, and engage in logical reasoning. It encourages students to question assumptions, challenge existing knowledge, and seek a deeper understanding of scientific concepts.

By including argumentation as a science practice, the NGSS aims to develop students' scientific reasoning, critical thinking, and communication skills. It encourages students to engage in evidence-based discussions, evaluate scientific claims, and actively participate in scientific inquiry, fostering a deeper understanding of scientific concepts and the nature of science.

The CER method is a framework commonly used to teach argumentation in science education. CER stands for Claim, Evidence, and Reasoning. It provides a structured approach for students to construct scientific arguments and communicate their understanding. Here's an overview of each component of the CER method:

1. Claim: A claim is a statement that answers a scientific question or addresses a problem. It is the central idea or conclusion that students are trying to support or refute through their argument. The claim should be clear, specific, and based on evidence.

2. Evidence: Evidence consists of the data, observations, and scientific information that support the claim. It serves as the foundation for the argument and should be relevant, accurate, and credible. Students should select and present evidence that is directly related to the claim and supports their reasoning.

3. Reasoning: Reasoning is the logical explanation or justification for how the evidence supports the claim. It involves making connections, explaining cause and effect relationships, applying scientific principles, and providing a logical sequence of thought. Reasoning helps students explain why the evidence is relevant and how it supports their claim.

For more information, see this article: https://www.modelteaching.com/education-articles/writing-instruction/claim-evidence-reasoning-cer

Teaching Cases