Topic: Water resources and their protection

Target group

8th‑grade students of elementary school

Core curriculum

General requirements

IV. Reasoning and applying the acquired knowledge to solving biological problems. Student:

1. interprets information and explains causal relationships between phenomena, formulates conclusions.

Specific requirements

VII. Ecology and environmental protection. Student:

9. presents renewable and non‑renewable natural resources and proposals for rational management of these resources in accordance with the principle of sustainable development.

General aim of education

You will learn what kind of water resources humanity has and how it should be protected

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to explain where drinking water comes from in nature;

• to explain why so much water on Earth is not safe to drink;

• to indicate sources of water contamination;

• to list ways to save water.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• exposing

  • exposition.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Before classes

• Students get acquainted with the content of the abstract. They prepare to work on the lesson in such a way to be able to summarize the material read in their own words and solve the tasks themselves.

Introduction

• The teacher explains the aim of the lesson and together with students determines the success criteria to be achieved.

• Students interpret the cover illustration, indicating its relationship with the subject and goals of the lesson.

Realization

• The teacher asks students to read the abstract themselves, paying particular attention to the illustrations.

• The lecturer discusses the structure of water resources in the world and addresses the issue of drinking water shortages on the Earth. Then he asks the students whether they know why drinking sea water is harmful to the body. To help students find the right answer, the teacher demonstrates before the class slices of freshly cut vegetables containing a lot of water (tomato, cucumber, etc.) before and after sprinkling them with salt. Students state that sprinkling chopped vegetables with salt causes the juice to be separated.

• The teacher divides the class into groups. Each group assigns one of the following topics to the study based on resources from the lessons: water quality in the main rivers of Poland; causes of water contamination; saving water in the household; saving water in gardening; use of rainwater; the size of the water footprint in various countries around the world. Students can use the Internet and other available sources while working.

• The representative of each group refers to the assigned topic. Students from other groups ask for additional explanations, ask questions and discuss with the referring group. If necessary, the teacher complements students' statements.

• Students carry out the interactive exercises checking the level of knowledge learned during the lesson. The teacher initiates a discussion during which the correct solutions for all the exercises performed by the students are discussed.

Summary

• The teacher asks a willing student to summarize the lesson from his point of view. He asks other students if they would like to add anything to their colleague's statements.

Homework

• Imagine that you have the opportunity to interview an academic - a specialist in the field of today's lesson. What questions would you like to ask him? Write them down.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Water resources and their protection

Earth observed from space is blue, because 71% of its surface is covered by water reflecting the blue part of the spectrum of sunlight. A huge amount of water on Earth is salty and therefore undrinkable. Freshwater resources on Earth are relatively small – they constitute only 3% of water resources in total.

Poland is one of European countries with the smallest drinking water resources per capita. Only Malta and Belgium have smaller water resources per capita. In Poland, one person can use about 1580 mIndeks górny 3³ of water annually.

Water in nature constantly circulates between water reservoirs, the atmosphere and land surfaces. Oceans are key here. Their surface evaporates constantly and floating water vapor is carried by wind. When the air cools down, the water vapor condenses and forms clouds. When small droplets of water contained in the clouds coalesce into larger drops, they fall down as atmospheric precipitation on, among others, lands. Some part of rainwater infiltrates into the soil and the other part flows into streams and rivers. The rivers carry it to seas and oceans where it evaporates again.

Water evaporates also on land. Some part of the rainwater accumulates in freshwater reservoirs, the other part moistens the soil and is taken up by plants. They also lose water in the transpiration process, increasing air humidity. Some part of the rainwater infiltrates into the ground and accumulates in underground watercourses several to several dozen meters below the surface. The water penetrates rock layers and cleans itself from biological contaminants self‑cleaning, i.e. it does not contain, for example, any bacteria. Such water is located at least 3‑4 m below the surface and supplies, for example, drinking water intakes.

The availability of water is affected not only by its consumption in households and production plants. Rainfall in Poland would be sufficient for our needs if it wasn't for environmental pollution affecting directly and indirectly water quality.

Saving water involves, among others, preventing its unnecessary outflow from a water system, rational use and limiting the use of artificial fertilisers, plant protection products and detergents.

Rainwater is an unused source of water. It can be used, for example, for watering the grass or flushing toilets. This solution is used, among others, at the Municipal Stadium in Wrocław.

It takes much water to produce food and other goods, so you waste water when you buy them unnecessarily.

To estimate the use of water, including not only water needed for drinking, washing and laundering, but also for the production of food, objects and devices, the concept of water footprint was introduced. It is a measure of water needed for the production of a particular good. For example, it was found that the production of 1 kg of chocolate takes over 17 thousand liters of water.

States, which are large food importers, use water resources of people inhabitating regions of its origin.

• Only 3% of water on Earth is fresh water and that is why its resources should be protected.