SECTION 2: LEARNERS GUIDE

Transcription

1 CAPACITY BUILDING TRAINING FOR CATCHMENT MENTORS (CHAMPIONS) INTRODUCTION TO THE WATER CYCLE MODULE 5 (B) SECTION 2: LEARNERS GUIDE Integrated Water Resources Management Strategies, Guidelines and Pilot Implementation in Three Water Management Areas, South Africa Department of Water Affairs and Forestry South Africa This report contains restricted information and is for official use only. Ref. J. No. 123/ Carl Bro a s FPCD Date: September 2003

2 HOW TO USE THIS MANUAL The content of this training material is in line SAQA guidelines THIS WORKBOOK BELONGS TO: HOW TO USE THIS MANUAL This manual provides an introduction to the Water Cycle. It provides the participants with the necessary information to enable them to understand the water cycle. They will also be able to identify the various forms of water and how these fit into the water cycle. It is expected of the participants to attend the training sessions and participate in all the exercises. It would be very useful to carefully study the whole manual. You are also welcome to make notes on this manual, as needed, in the wide right margin of each page. In addition, the results of the various exercises must be verified with the information in this manual. You must make sure that you understand the work presented in the notes and never hesitate to ask questions. We hope you will enjoy this course and gain much from it. SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE i

3 TABLE OF CONTENTS TABLE OF CONTENTS 1.1: WATER KNOWLEDGE 1 1.2: DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE Background The Water Cycle The Influence of the sea on Climate and Temperature The Elements of the Water Cycle: The Relation of the Elements to One Another 9 SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE ii

4 WATER KNOWLEDGE INTRODUCTION TO THE WATER CYCLE MODULE 5 (B) 1.1 WATER KNOWLEDGE Respect Do not waste water Do not pollute Pay for water Protect environment Individual Instruction ACTIVITY 1 Study the above-mentioned Water Knowledge Hand and rearrange the letters inside the brackets, in order to arrive at the correct answer. Without water everything will (dei). As water is life, we must (erpscet) water and use it wisely. That is the first step to Water Knowledge. If you (esu) too much water and don t conserve it, you are wasting a valuable natural resource. We must learn not to waste water, but rather to use it (snesbily). This is the second step to Water Knowledge. When you pollute a water source, you make it unhygienic and even dangerous for humans, animals and even aquatic fauna. Think of ways people pollute the water, and try to find a (nltoisou) to the problem. This is the third step to Water Knowledge. Why must we pay for water, if it falls as rain? In reality we pay for the infrastructure in order to be able to use the water. We pay people who look after rivers and (msad), for water purification works, where water is (dfriepui), and for infrastructure, which transport water to reservoirs, and our (seshou). This is the fourth step to Water Knowledge. Action means doing. If you see an environmental problem, you must do something about (ti). Many people know the answer. We must all conserve our water (scrusoe). If we care about water, we must (versenoc) and (tectrop) the environment. This is the fifth step to Water Knowledge. SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 1

5 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE 1.2 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE The purpose of this unit is to create awareness of the natural water cycle and identify all the elements of the water cycle. It will assist the participant in drawing conclusions from it and understanding the relationship between the various elements BACKGROUND Matter and energy The earth is made up of two main Components namely: MATTER ENERGY All matter on earth is made up of: for example: The most important source of energy is the sun. It provides: The air that we breath Photosynthesis in plants. Other gasses. Heating for our houses. The water that we drink. Wind strengths. Minerals such as gold, iron ore, copper Formation of fossil fuels such as coal and oil. Elements such calcium, etc. Soil, sand, stones, etc. as phosphates, To conserve matter and energy, materials must be reused or recycled The various forms of water Water can be found in a variety of forms: 1. Water as a liquid 2. Water as a solid SECTION 2: LEARNERS GUIDE: 3. Water as gas or vapour SEPT 2003 PAGE 2

6 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE When we transmit heat energy, ice melts into water and if there is enough heat, the liquid changes into gas/vapour. When heat is removed from water vapour the vapour will condensate into a liquid. If the cooling continues to below freezing, the liquid will turn into ice. ACTIVITY 2 Group work Come together in small groups of approximately five: Discuss the following questions and complete the table according to your answer. Examples of water in nature that appears in the following conditions: WATER IN NATURE CONDITION EXAMPLES 1. Solids 2. Liquid 3. Gas/vapour Natural Water Sources The earth s water comes in three zones: Atmosphere (in the air) Surface (on the ground) Underground About two thirds (71 %) of the earth surface comprises of water. The following natural water sources appear on earth: 1. Ocean s and Sea s 2. Rivers, lakes or wetlands SECTION 2: LEARNERS GUIDE: SEPT Underground Water PAGE 3

7 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE The form of water (i.e. fluid, solid or gas) is mostly determined by temperature. Although water is constantly changing form sold, to fluid to gas and vice versa, the total volume on earth stays constant. Individual Instruction: ACTIVITY 3 Carefully read the following advertisement. Answer the following questions in your workbook: The earth contains salt water found in and. Fresh water amounts to and is stored in,,, and. Give four reasons why you need water. Since when did we have access to water? SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 4

8 1.2.2 THE WATER CYCLE DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE Different ecosystems can be found on earth and each ecosystem has its own climate. Water from the oceans or seas is not suitable for human consumption because of the salt content. The sun is an enormous power plant and a third of the energy is absorbed in the evaporation of seawater. The water vapour is distributed over the earth s surface by wind and when sufficiently cooled through the rising of air, precipitation in the form of rain, snow or hail. This process is known as the Hydrological cycle. We will learn more about it later. Ecosystem is a community of plants and animals living together. Hydrology Science that looks on water being a liquid from above and under the surface of the earth. Evaporation Water changes into a gas (usually through the heat of the sun). The sun is a strong source of energy. About a third of the energy delivered by the sun, is absorbed in the form of evaporating seawater. The evaporation forms clouds. The wind distributes the clouds over the earth. When the clouds cool down sufficiently, condensation starts, and it falls to the earth in the form of rain, snow or hail. This process is known as the water cycle. The following illustration indicates this cycle: Water vapour condenses and form clouds. When clouds cool down, the vapour condensates and forms water. The sun heats the water in the oceans, and dams. The water turns into water vapour. The water, snow or hail falls on the earth. This eventually flows into rivers that flow into the ocean. SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 5

9 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE ACTIVITY 4 Group work: Study the following statement as a group: We know we cannot drink seawater because it is salty. Find solutions in your group to the following questions: Can you think of at least three reasons why the sea is an important storage facility? Think of ways to desalinate seawater THE INFLUENCE OF THE SEA ON CLIMATE AND TEMPERATURE The greatest storage area is the oceans and seas. You have already been informed of how much of the earth s areas are covered with water. In the following diagram we can see the influence the oceans have on climate. ACTIVITY 5 Work together in pairs Use a map of South Africa and determine the following: Try to find out where your city or town lies in relation to where the ocean and sea is. How will sea levels and the distance from the sea influence your weather? Which weather changes will you experience at the height above sea level and the distance from the sea? SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 6

10 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE ACTIVITY 6 Individual assignment Answer the following questions in your handbook: Where do you get your water? Name the different ways in which people in South Africa get water. Use the pictures below to assist you. How does water get into rivers and taps? You re nearest river or dam forms part of which catchment area? THE ELEMENTS OF THE WATER CYCLE SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 7

11 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE When we think about the water cycle, we look at the oceans, lakes, rivers, streams and wetlands on the earth s surface. Water from the surface moves in the water cycle through a process of evaporation. Evaporation occurs when energy/heat from the sun change water into vapour. Water vapour can also occur through transpiration. Transpiration is the process where plants get rid of water through small ducts on the bottom of their leaves. This process allows water to evaporate into the atmosphere. Only water evaporation leaves insoluble such as salts behind. Evaporation results in condensation. Water vapour rises and is cooled by air in the atmosphere. Water vapour condenses and it forms small water droplets. Millions of water droplets are condensed and form clouds or mist. Water condenses only in the presence of small particles of dust around which the droplet can be formed. Condensed water vapour can occur as rain, dew, hail or snow. Only the rain, snow and hail that falls to earth is of importance to humans. When the atmospheric pressure is right, the droplets in the clouds will grow and form bigger drops and rain will occur. When water vapour changes into liquid or solid particles, water or ice particles are formed in the clouds, resulting in rain, mist, dew, snow or hail. The process of evaporation, condensation and precipitation shows that water moves from the earth s surface into the atmosphere and back to the earth. This process is known as precipitation. Ground runoff refers to the amount of water that comes back to earth through rain and movement over the land surface. Water flows to the lowest point in streams and rivers. Small streams flow into bigger streams then into rivers and finally into the ocean. Runoff forms an important part of the water cycle because through this process the water moves back into the oceans where evaporation again takes place. Infiltration is an important part of the process where rainwater filters into the ground and is stored in underlying rock formations. Some of the water resurfaces as a fountain. Some of the water remains underground and is known as ground water. When water oozes through the rock formations it is filtered of impurities. This filtering process helps clean the water. Ground water Water that is under the ground (earth). Infiltration Gradual inflow of material, called a process or action. Precipitation Rain, hail or snow or any other form of water that falls on earth. SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 8

12 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE ACTIVITY 7 Individual assignment Study the following water cycle from the sea to homes: Answer the following questions in your handbook: Explain the process where water comes from the sea to form clouds and rain. What happens to rain when it falls to the earth? Why should people store water in dams? Describe what happens at water purification plants. Do you think that people in urban areas have more clean water than people in rural areas? THE RELATION OF THE ELEMENTS TO ONE ANOTHER Water constantly circulates between the atmosphere, ocean and land. This cycle in an important process that helps to sustain life on Earth. The same amounts of water that evaporate come back as rain. Unfortunately rain does not fall equally on earth, as there are deserts, droughts, floods and marshes. When and where the rain falls is dependant on many different conditions (changing circumstances) such as: Changes in temperature Atmospheric pressure Wind direction SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 9

13 DEMONSTRATE KNOWLEDGE OF THE WATER CYCLE Let us study the following example: Sea Land During the day the wind blows from a cool sea or ocean and carries vapour across the land. The warmth of the earth s surface warms the air. The air becomes lighter, causing it to rise (this causes changes in atmospheric pressure). When moving air blows against a mountain range the air will be forced to rise resulting in cooling. Water vapour will condensate and may result in rain on the oceans side of the mountain. The wind, devoid of water vapour blows across the mountain, resulting in a drier climate on the other side. For this and various other reasons, the amount of rain is highly variable across the country. To summarise, we can deduct the following: When water evaporates condensation takes place and forms clouds. The clouds move across the land and results in rain, snow or hail. The water fills the streams and rivers and finally flows back into the oceans where the evaporation process is renewed. Individual assignment Activity 8 Explain the following: Show with the aid of a sketch and necessary captions, how you will present the water cycle. Write the process that will occur to supplement water points in your environment. SECTION 2: LEARNERS GUIDE: SEPT 2003 PAGE 10