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UNIT D Grade 8 – Water Systems
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UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Dec 16, 2015

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Page 1: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

UNIT D

Grade 8 – Water Systems

Page 2: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Where does the water we drink come from?

Page 3: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Big Ideas of Water Systems

Water is crucial to life on EarthWater systems influence climate and weather

patternsWater is an important resource that needs to

be managed sustainable Chapter 10: Safe Drinking Water Chapter 11: Water Quality Chapter 12: Water, Weather, and Climate

Page 4: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Safe Drinking Water - Introduction

Why is it often unsafe to drink water directly from nature?

Why can’t fresh water just be pumped into our homes?

What do you think must happen in order for water to be safe for humans to consume?

Page 5: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

KEY QUESTION

Where does water come from?Suggestions?

Page 6: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Looking Ahead…

• We use water in many different ways ever day.• Water circulates around Earth in the water

cycle.• The skills of analysis can be used to determine

personal water use and ways to reduce water use.

• Water must be treated before it is safe to drink.• The skills of technological problem solving can

be used to design and build a sample water filtration device.

• The media report on water-related issues in different ways.

Page 7: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Vocabulary

• Water cycle• Melting• Sublimination• Evaporation• Condensation• Deposition• Freezing• Runoff• Groundwater

• Aquifer• Water table• Precipitation• Polar ice sheet• Icecap• Glacier• Water treatment• Floc• Sustainability

Page 8: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

10.2 What is Water?

OBJECTIVE: Demonstrate an understanding of the characteristics of the earth’s water systems and the influence of water systems on a specific region

Does water always look clean and pure?Clean vs. Dirty water sample

Page 9: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Why do we need water?

Helps the body transport substances to all the tissues and organs

Needed in order for chemical reactions to take place

Keeps the body coolEssential for our health

Page 10: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Describing Water

Most water in nature is not “pure” Some have a different colour or smell to them

They are usually a mixture of water and other substances

Some substances mixed with water are needed and some are dangerous

Page 11: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

The Water Particle

Made up of HYDROGEN and OXYGEN (H2O)These particles are joined together

Page 12: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

States of Water

• Solid (ice) – definite shape; water particles cannot move freely

• Liquid (water) – particles vibrate faster; free to move around

• Gas (water vapour) – particles are very far apart; have a lot of energy and move quickly in all directions

• They all behave differently

Page 13: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 269 - Homework

• Describe a particle of water. What other particles make up a particle of water?

• You are given a sample of tap water that is clear, yellowish, and odourless. Is this a sample of pure water? Explain.

• Choose one of the states of water– Draw a labeled diagram to show the arrangement of

water particles in this state.– Describe the arrangement of water particles in this

state

Page 14: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 15: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 269 - Homework

• Describe a particle of water. What other particles make up a particle of water?

• You are given a sample of tap water that is clear, yellowish, and odourless. Is this a sample of pure water? Explain.

• Choose one of the states of water– Draw a labeled diagram to show the arrangement of

water particles in this state.– Describe the arrangement of water particles in this

state

Page 16: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

10.3 The Water Cycle

Water vapour is an invisible gasSteam coming off of a boiling kettle is not

water vapour…it is condensed liquid waterWater vapour that escapes from a kettle is

invisible, but, outside the kettle, the water vapour quickly condenses when it meets the cooler air to form a mist that we call “steam”

Page 17: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Changes of State• Handout• Melting: change of state from a solid to a liquid;

solid gains more thermal energy• Sublimination: change of state from a solid to a

gas without first becoming a liquid; solid gains thermal energy

• Evaporation: change of state from a liquid to a gas; liquid gains thermal energy

• Condensation: change of state from a gas to a liquid; gas loses thermal energy

• Despoition: change of state from a gas to a solid; gas loses thermal energy

• Freezing: change of state from a liquid to a solid; liquid loses thermal energy

Page 18: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Changes of state …

Condensation

EvaporationMelting

Freezing

GASLIQUIDSOLID

SUBLIMINATION

DEPOSITION

Increasing thermal energy of particles

Decrease thermal energy of particles

Page 19: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Melting, Evaporation and Sublimination in Nature

• Runoff: Water from precipitation and melting snow

• Groundwater: water that comes through soil and cracks in rocks; underground springs and wells

• Aquifer: a geological formation of loose rock or soil that is saturated in groundwater

• Water table: loose rock and soil below the Earth’s surface are saturated with water

Page 20: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Condensation, Freezing, and Deposition in Nature

Precipitation: solid or liquid water that falls to Earth’s surface

Polar ice sheet: sheet of ice covering the North or South Poles

Icecap: a large block of ice that permanently covers land

Glacier: a river of ice formed from snow; moves slowly downhill

Page 21: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 273 - Homework

• Look at Figure 2. Where can you find each of the three states of water?

• Describe the water cycle. Draw your own labelled diagram.

• Briefly describe how solid and liquid water may be converted to water vapour.

• Describe how water vapour changes into solid and liquid water above Earth’s surface.

• Does all surface runoff move directly into rivers, lakes, and oceans? Explain.

Page 22: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 23: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 273 - Homework

• Look at Figure 2. Where can you find each of the three states of water?

• Describe the water cycle. Draw your own labelled diagram.

• Briefly describe how solid and liquid water may be converted to water vapour.

• Describe how water vapour changes into solid and liquid water above Earth’s surface.

• Does all surface runoff move directly into rivers, lakes, and oceans? Explain.

Page 24: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

10.5 Making Water Drinkable

What do you think is involved in the water treatment process?

What are some different methods to make our water drinkable?

In this section, we will be learning about the process for treating wastewater or sewage in a water treatment plant

Page 25: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

The Water Treatment Process• Remove large objects from the water; the

screen at the end of the tube blocks large objects from entering

• Water enters a large tank where a chemical is added (alum); alum make clumps in the water where most of the waste goes to (floc)

• Water and floc enter a settling tank; floc settles to the bottom

• Partially clean water moves through a sand and charcoal filter which removes remaining waste solids and small pieces; water is now clear, colourless and odorless

• Water still may contain some bacteria and so chlorine and ozone can be added to kill these organisms

• The water is ready to use

Page 26: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Other Treatment Options

Type of Treatment How it works When it is used

Reverse Osmosis

Ultraviolet (UV) Radiation

Water Softening

Boiling

Page 27: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 278 - Homework

• List and describe the six main steps that water goes through in the water treatment process.

• Is clear, colourless, and odourless drinking water always safe to drink? Explain.

• Describe how the membrane works in the reverse osmosis process. Use a labeled diagram in your description.

• Why is it important to ensure that treated water remains safe to drink when it is stored after treatment?

• Describe one way to make stored water safe.

Page 28: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 29: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 278 - Homework

• List and describe the six main steps that water goes through in the water treatment process.

• Is clear, colourless, and odourless drinking water always safe to drink? Explain.

• Describe how the membrane works in the reverse osmosis process. Use a labeled diagram in your description.

• Why is it important to ensure that treated water remains safe to drink when it is stored after treatment?

• Describe one way to make stored water safe.

Page 30: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Chapter 10 Review

Page 284 and 285Review questions: #1-12

Chapter 10 Quiz on _______________

Page 31: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 32: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Chapter 11 – Water Quality

What does polluted water look like?Does it always look dirty?

Some substances and micro-organisms that pollute our water are not always visible

It may look clean but there is sill a possibility that it can be dirty

Page 33: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Chapter 11 Intro Photo

What is shown in the picture?What pollutants can you see in the water?How might have these pollutants enter the

body of water?

Page 34: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

KEY QUESTION

What substances are in water, and where do they comes from?

Page 35: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Looking Ahead…

Only a tiny fraction of the water on Earth is fresh water available for out use.

Water can contain many ifferent contaminants.

The skills of scientific inquiry can be used to test water quality.

Water must be used sustainably.Wastewater must be treated before being

returmed to the environment.

Page 36: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Vocabulary

SalinityConcentrationDesalinationContaminantFertilizerHerbicidePesticideTurbid

Thermal pollutionWatershedBioremediationSewer systemBlackwaterGreywaterWastewaterStormwater runoff

Page 37: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

11.1 Fresh Water and Salt Water

Can we drink salt water? Large quantities can be deadly Kidneys don’t have the ability to process a high

concentration of salt

Page 38: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Salt WaterSalt Water Fresh WaterFresh Water

Contains a lot of saltSwimmers can easily

float in the waterHas a lot of salinity

(the amount of salt in the water)

Has a greater density

The salinity in fresh water is less than 1%

Salt Water vs Fresh Water

Page 39: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Try This Activity…

Materials: Small graduated cylinder 2 cups or small bowls Marker Teaspoon tap water 2 paper labels Salt

Page 40: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 291 - Homework

What percentage of water on Earth is fresh water?

Describe two special characteristics of salt water.

Why are engineers developing desalination technologies?

Briefly describe a desalination process.What can make desalination expensive?Name two renewable energy sources that

can be used in desalination.

Page 41: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 42: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 291 - Homework

What percentage of water on Earth is fresh water?

Describe two special characteristics of salt water.

Why are engineers developing desalination technologies?

Briefly describe a desalination process.What can make desalination expensive?Name two renewable energy sources that

can be used in desalination.

Page 43: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

11.2 Contaminants in Water

How does water become polluted?Where are some specific places where water

is contaminated?Contaminants: an unwanted substance in a

mixtureWhat human activities have an effect on

water sources? Farming, road salting, garbage dumping, burning

fossil fuels, etc.

Page 44: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Sources of Chemical Contaminants

SaltMineralsFertilizersHerbicides and PesticidesAcid RainOther Toxic Chemicals

Page 45: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Salt

Can come from road salt, gravel, and sand in the winter

When the snow melts, it carries the salt into nearby forests on washes into bodies of water

Page 46: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Minerals

Can come from rocks that dissolve into waterLimestone (example) is a soft rock that

dissolves in water which adds calcium carbonate to the water

Page 47: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Fertilizers

Fertilizer: a substance used to give nutrients to plants, usually to increase crop production

Fertilizers can be carried during rainfalls to streams and lades

Page 48: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Herbicides and Pesticides

Herbicides: a chemical substance used to kill or slow the growth of certain plants, often used to kill weeds that compete with crop plants

Pesticides: a chemical substance used to kill animal pests, often used to kill insects that damage crops Ex: DDT (kills flies, mosquitoes and potato beetles)

Page 49: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Acid Rain

Chemicals that are released into the air from burning of fossil fuels

These chemicals reach with water vapour to form acid rain

Page 50: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Other Toxic Chemicals

Transportation industryGarbage dump and sewageShip spills (oil spills)

Page 51: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Sources of Biological Contaminants

ManureE-coli (damages local water)Local water containing parasitesAnimal feces

Page 52: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 295 - Homework

Name two parts of the water cycle in which contaminants can be introduced.

What are the two main categories of contaminants in water? Why are they a problem?

Choose 2 chemical contaminants that could be found in a freshwater source. For each one, Identify a source of the contaminant Describe how the contaminant got into the water

Briefly describe how a biological contaminant was able to get into groundwater wells at Walkerton.

Page 53: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 54: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 295 - Homework

Name two parts of the water cycle in which contaminants can be introduced.

What are the two main categories of contaminants in water? Why are they a problem?

Choose 2 chemical contaminants that could be found in a freshwater source. For each one, Identify a source of the contaminant Describe how the contaminant got into the water

Briefly describe how a biological contaminant was able to get into groundwater wells at Walkerton.

Page 55: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

11.3 Testing Water Quality

Water quality is an indicator of how good or bad the water in a certain system is

What would you classify as “good” water?What would you classify as “bad” water?

Page 56: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

When Testing Water…

Look at the turbidityTest the temperatureFind out the acidity of the water (pH)Test the salt content (salinity)Look for other dissolved substances in the

water

Page 57: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Turbidity

Turbid: not clear; containing tiny specks of sediment or other solid matter Makes the water cloudy

Clear water is better than turbid water

Page 58: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Temperature

Warm water contains less dissolved oxygen than cold water

Thermal pollution: increasing the temperature of the water (kills the bacteria)

Page 59: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Acidity

Water is acidic if it contains chemicals such as sulfuric acid or nitric acid

We can measure the acidity with an indicator that has a different colour for every pH level

Water is acidic if it’s pH is below 7; basic if it is above 7

Page 60: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Salinity

You need a conductive apparatusElectricity is used

Page 61: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Other Dissolved Substances

ChlorineNitratesIron and copperCalcium and magnesium

Page 62: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 297 - Homework

List at least three factors mentioned in this section that decrease water quality.

How can you test a water source to see whether it is acidic or not?

What is thermal pollution? How do nuclear power plants contribute to thermal pollution?

How could each of the following substances enter a freshwater source? Chlorine - calcium Nitrates - acid

Page 63: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 64: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 297 - Homework

List at least three factors mentioned in this section that decrease water quality.

How can you test a water source to see whether it is acidic or not?

What is thermal pollution? How do nuclear power plants contribute to thermal pollution?

How could each of the following substances enter a freshwater source? Chlorine - calcium Nitrates - acid

Page 65: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

11.4 Watersheds

The highest parts of North America are called the continental divides The divide the waters on each side, which helps the

water flow downwards

80% of Canada’s surface water goes towards the Arctic Ocean

Figure 1

Page 66: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Watershed

Watershed: an area surrounded by high land and drained by a river and its area; all the runoff in the watershed leaves the watershed at the same exit

Read page 299 and 300

Page 67: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 300 - Homework

Describe how a continental divide affects the direction of water flow over land.

Name a continental divide, and describe where it is.

Explain the meaning of the term “watershed”.

Briefly describe the role of a Conservation Authority.

What is the process called in which organisms are used to remove contaminants from the environment?

Page 68: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 69: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 300 - Homework

Describe how a continental divide affects the direction of water flow over land.

Name a continental divide, and describe where it is.

Explain the meaning of the term “watershed”.

Briefly describe the role of a Conservation Authority.

What is the process called in which organisms are used to remove contaminants from the environment?

Page 70: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

11.7 Wastewater Treatment

Water goes through 5 stages of treatment Preliminary Treatment Primary Treatment Secondary Treatment Final Treatment Solids Processing

Page 71: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Preliminary Treatment

Wastewater passes through a bar screen which removes larger objects

The wastewater is slowed down and put into a tank where it settles

The sand, gravel and other heavy objects sink Water goes onto the next stage

Page 72: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Primary Treatment

The wastewater goes into a large settling tank

Sits for several hoursSolid particles settle at the bottom of the

tank

Page 73: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Secondary Treatment

A process that removes organic matter from wastewater

Oxygen is added which helps micro-organisms to grow which will eat the bacteria in the water

Any remaining solids continue to settle on the bottom

Page 74: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Final Treatment

Wastewater is disinfected to kill harmful organisms

Clean water is released into the lake

Page 75: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Solids Processing

The solids that were removed from the water in the primary and secondary treatment stages is sent to the digester

After 15 days, bio-solids (wet, soil-like material) are sent to the landfill or are incinerated

Page 76: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Types of Water

Blackwater: water that contains feces and urine; also called “sweage”

Greywater: water that has been used for cooking, laundry, bathing, or similar tasks

Wastewater: water that has been used or contaminated by human activity; blackwater and greywater

Stormwater runoff: water, usually from precipitation, that runs off roods, lawns and paved areas

Page 77: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 307 - Homework

Explain in your own words how greywater is different from blackwater.

List two sources of wastewater.What is the purpose of the primary stage of

sewage treatment?Explain the difference between a septic

system and a sewage system.Explain the difference between a septic

system and a sewage system.

Page 78: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Chapter 11 Review

Page 310 and 311Questions: #1-10, and 13

Quiz on ______________

Page 79: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 80: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Ch 12 – Water, Weather, and Climate

What do you think of when you hear the word water?

What do you think of when you hear the word weather and climate?

Do changes in climate effect the changes in weather? Changes in climate do not necessarily cause

immediate or predictable changes in weather (in the spring, the climate in Ontario is getting warmer, however, that does not mean that every spring day is warmer than the previous day)

Page 81: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Chapter 12 Introduction

What is in the picture on page 314?What is happening?Why do you think this is happening?

Flooding has happened from the river which causes erosion which collapses the road

What does this scene have to do with weather? More water than usual because of unexpected

weather changes which causes the river to overflow and the road to break apart

Page 82: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Looking Ahead

The climate of a region and the weather on any particular day, are affected by large bodies of surface water

Climate affects water’s temperature and changes of state on Earth

Research skills can be used to assess issues related to local and global water supply

Global warming is affecting water systems around the world

The long-term sustainability of water systems depends on how well we manage and care for water

Page 83: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

KEY QUESTION

How do water systems, weather, and climate affect

each other?

Page 84: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Vocabulary

WeatherClimateHeat capacityHeat sink

ConvectionGlobal warmingFlood plain

Page 85: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

12.1 Surface Water and Climate

OVERALL EXPECTATION: Demonstrate an understanding of the characteristics of Earth’s water systems and the influence of water systems on a specific region

What are factors that affect our climate? Distance from the equator How close we are to bodies of water Altitude (height above sea level)

Page 86: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Facts

What is the climate in areas that are higher above sea level? Coller climates Top of mountains are usually cooler

What is the climate in areas that are close to bodies of water? Winds and ocean currents effect climate

What is the climate like in areas close to the equator? Hotter climate

Page 87: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

What is the climate like where we live?

Page 88: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

What is the difference between weather and climate?

CLIMATE is what we expect (seasonal)WEATHER is what we get (day to day)

Temperatures in Air and on Land Activity?

Page 89: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Weather and Climate

Weather: day-to-day environmental conditions in a given place at a given time; includes temperature, cloud cover, wind speed, and precipitation

Climate: an average of weather conditions in an area over 30 years

Page 90: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Causes of Temperature Differences

How much energy is coming from the sunDifferent seasons

Page 91: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Heat Capacity

The Earth supports life because of its heat capacity

Heat capacity: a measure of the amount of thermal energy needed to increase temperature; how much thermal energy an object can hold the higher the heat capacity of a substance, the more

thermal energy it can store Soil and rock can not store as much heat as water; they

need less thermal energy to heat up Gravel or rocks release thermal energy faster than

water

Page 92: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Heat Sinks and Climate

Heat sink: matter that absorbs thermal energy but does not change state or significantly increase in temperature Water (energy is always moving around and energy

goes through the entire body) Ocean water never really heats up (it does get warm)

Convection: circulating currents heat up the gas or liquid from fast or slow moving particles Water circulates Air circulates

Page 93: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 319 – Homework

What is the difference between weather and climate?

Explain in your own words how the heat capacity of water makes any body of water a good heat sink.

Describe how warm water at the surface of a lake or ocean mixes with deeper, cooler water.

Why do areas close to large bodies of water have milder climate than inland?

Page 94: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

t

Page 95: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 319 – Homework

What is the difference between weather and climate?

Explain in your own words how the heat capacity of water makes any body of water a good heat sink.

Describe how warm water at the surface of a lake or ocean mixes with deeper, cooler water.

Why do areas close to large bodies of water have milder climate than inland?

Page 96: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

12.2 Glaciers, Polar Ice and Global Warming

Are greenhouse gases and global warming the same thing? No…the greenhouse effect has an effect on global

warming but they are not the same thing

What is the greenhouse effect? Carbon dioxide and methane are some examples of

greenhouse gases More thermal energy gets trapped in the atmosphere

Page 97: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

What do you already know about global warming?

Page 98: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

The Effects of Climate Change

When climate is cold, there is an ice build up on glaciers; more ice covers the land

If there is more precipitation or if more ice melts, then the ice coverings start to melt

Global Warming: an increase in the Earth’s average atmospheric temperature

Page 99: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

What happens in Canada?

Global warming is lowering the water levels in Lake Ontario

Water is evaporating quickly

Page 100: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

El Nino

A large current of warm water that forms in the Pacific Ocean

Warm water current moves north which warms the air above

Warm air moves inland which can increase the temperatures in winter

Less snow and precipitation

Page 101: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Storms and Hurricanes

Warm air currents that develop into hurricanes

Hurricane winds push ocean water around to create storms

Page 102: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 322 - Homework

The Athabasca Glacier in Western Canada continues to shrink every year. What does this suggest about the climate in that region? Explain your answer.

In your own words, explain how rising sea levels are an indication of global warming.

Explain what is happening to water levels in the Great Lakes.

What is El Nino? Describe the effects of El Nino on Canadian weather.

Explain how hurricanes form.

Page 103: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?
Page 104: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 322 - Homework

The Athabasca Glacier in Western Canada continues to shrink every year. What does this suggest about the climate in that region? Explain your answer.

In your own words, explain how rising sea levels are an indication of global warming.

Explain what is happening to water levels in the Great Lakes.

What is El Nino? Describe the effects of El Nino on Canadian weather.

Explain how hurricanes form.

Page 105: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

FloodsFloods DroughtsDroughts

Caused by heavy rainfall or rapid snow melt

Add moisture to dry land, provide nutrients, etc.

Caused by dry weather conditions where water evaporates faster than it is replaced

Can cause forest fires

12.4 Floods and Droughts

Page 106: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

FloodsType 1: Rapid snowmelt or heavy rainType 2: Flash floods are the most deadly and

damaging Produced by a sudden storm

Type 3: Storm surges are floods that occur along coastlines when hurricanes come ashore Very dangerous One came after Hurricane Katrina which killed and

destroyed many

Type 4: Ice jam floods usually happen in the spring and is from river ice breaking up and being jammed into narrow parts of the river

Page 107: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Preventing Floods

New homes should not be built on flood plains (low area of land alongside a river)

Using dams to control water

Page 108: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Droughts

Less than 2.5 cm of precipitation annually = desert

6 months or more with no rain or snow = season drought

Humans use it to drink and bottle water to sell and therefore we lose even more water

Page 109: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 327 - Homework

How are floods and droughts sometimes good for the natural environment?

Briefly describe two strategies that would reduce the chances of homes being damaged by floods.

Does damming a river make the water source more sustainable? Explain your answer.

What human activities worsen the effects of drought?

How does soil compaction affect the water system?

Page 110: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

12.6 Water is Life

A lot of people do not have access to water while others over use it

World’s first “Water Day” – March 22, 2005

Page 111: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Page 330 - Homework

Describe, in your own words, the United Nations Millennium Declaration on water rights.

Explain how buying and selling water conflicts with the idea that access to clean water is a basic human right.

Page 112: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Chapter 12 Summary

Page 334 and 335Questions on page 336 and 337, #1-10

Page 113: UNIT D Grade 8 – Water Systems. Where does the water we drink come from?

Unit D Summary

Questions on page 340 and 341#1-8, 10 and 13

Unit D test on _____________