Year 11 Senior Science 8.2 Water for LivingFocus 1 & 2

Name: John Nkpolukwu Class: Science B for best

Teacher:

Miss Dionis

2

Water for Living Focus 1 & 2 Contents1. Syllabus 2. Glossary 3. Solutions 4. Experiment: Solubility of Materials 5. The Importance of Water as a Solvent 6. Known Water Content of Living Things 7. Experiment: Water Content of Living Things 8. Optimising Water Uptake in Plants 9. How Plants Reduce Water Loss 10. Experiment: Adaptations in Plants that Assist in Reducing Water Loss 11. How Animals Reduce Water Loss 12. The Water Cycle 13. Experiment: Representing the Earths Water 14. Types of Water 15. Mapping Water in the Local Area (Liverpool) 16. Problems with Groundwater 17. Catalyst Special: Groundwater 15/3/07 18. Salinity 19. Australias Ecosystems 20. Water Wise Rules

8.2

Water for Living

Contextual Outline The Earths water budget was essentially fixed as it cooled when gaseous water condensed and settled on the cooling planet. Free water exists in liquid form as surface and ground water and it is this water which is available for living things. It is also in the atmosphere as the main gas that absorbs back-radiation from the Earth to assist in stabilising the Earths surface temperatures and climatic conditions. The terrain and climate determine the amount of water available for an individual continent. Australia has an arid environment because its water budget is limited in most areas due to a combination of factors, such as the Great Dividing Range, which limits rain coming in from the east, the Papua-New Guinea Highlands, which limit rain entering inland from the north, and very cold atmospheric and ocean currents coming in from Antarctica, which limit rain entering Australia from the south. The NSW river systems have been disturbed by many factors, including run-off from pastoral systems and the damming and re-routing of others. There are now limits regulating the discharge permitted into the river systems and the health of these systems is continuing to improve. Large areas of land have been set aside as catchment regions for dams supplying urban environments and experience has shown that care of these catchments is essential for clean, pollution-free drinking water. This module increases students understanding of the nature and practice, the applications and uses of science and the implications of science for society and the environment. Assumed Knowledge Refer to the Science Years 710 Syllabus for the following: 4.7.5b) identify, using examples, the importance of water as a solvent 4.7.5c) describe aqueous mixtures in terms of solute, solvent and solution 4.8.1a) identify that living things are made of cells 4.9.5a) describe the water cycle in terms of the physical processes involved

Students learn to: 1. Water is essential for the health of humans and other living things identify the relative amount of water in a variety of living things describe the importance of water as a solvent in the bloodstream cells transpiration stream discuss ways in which plants optimise water uptake discuss ways, using examples, that plants reduce water loss such as: thick outer coating (cuticle) on leaves reduced leaves dropping leaves in times of drought discuss ways, using examples, that animals reduce water loss such as: excrete uric acid instead of urea nocturnal behaviour reduced activity lying in the shade burrowing underground Students learn to: 2. Water is an important factor in the maintenance of Australian environments outline types of surface and ground waters in the hydrological cycle such as: bore water artesian water the water table dams rivers lakes wetlands cave environments discuss the effects of water pollution and ground salinity on the continued supply of fresh water to living things and provide examples of these occurring in Australian environments identify possible solutions to environmental problems associated with the use of ground water outline one local, State or Federal Government policy on water-related issues in relation to increasing problems

Students: perform a first-hand investigation to demonstrate that substances dissolve in water and identify the solute and solvent in each case plan, choose equipment or resources for and perform a first-hand investigation to determine the amount of water present in a variety of fruits, vegetables and meat perform a first-hand investigation to identify adaptations of some plants that assist in reducing water loss gather, process and analyse information to identify the different ways in which a range of terrestrial animals reduce water loss

Students:

process information from secondary sources to map the location and type of surface and ground water in the local area analyse information from secondary sources to outline the relationships between rainfall and types of Australian ecosystems process, analyse and present information from secondary sources to assess human impact on one aquatic ecosystem or water source in Australia and identify some consequences of this impact and one possible rehabilitation technique

with water supplies across NSW

Students learn to: 3. A wide range of chemicals used in human activity may impact on water systems define the terms fertiliser, herbicide and pesticide and explain, using examples, why each is used in the Australian context identify the conditions under which fertiliser and pesticides may be carried into water systems assess the impact on water systems of the release of substances produced or used by households, such as: oils detergents bleaches and toilet cleaners insoluble materials sewage identify the use of and impact on water systems of substances such as: heavy metals (lead and mercury) phosphates nitrates identify the impact on aquatic ecosystems of factors such as accumulated sediment leaching from tips bioaccumulation 4. Strategies to reduce water pollution can be a result of personal initiative or government legislation describe some of the strategies that households can use to reduce water pollution identify conditions under which algal blooms may occur in the rivers of New South Wales describe impacts of algal blooms in rivers discuss alternative strategies to the use of chemicals in agriculture to reduce water pollution identify an example of technology being used and developed to reduce water pollution and discuss possible long-term effects of this strategy

Students: plan, choose equipment and resources for, and perform a first-hand investigation to determine the effect of various concentrations of fertiliser on plant growth process information from secondary sources on methods of bioassay for water purity

gather information from secondary sources to identify causes and impacts of algal blooms in waterways in NSW perform a first-hand investigation to determine the amount of water used per household for one activity such as water used per toilet flush water used per shower water used per washing machine cycle and identify ways in which it can be reduced gather, process and present information from secondary sources on the latest technologies being used to purify and treat water

Students learn to: 5. Water pollution at the local level impacts on global water quality discuss types of indicator organisms that are found in safe water supplies and those found in polluted water define what is meant by a catchment area identify a local catchment area and the sources of water feeding into this catchment describe possible sources of contamination that may enter catchments describe the types of tests that are used to monitor and assess local water quality explain how water quality in one area can impact on the water quality in other areas

Students: plan, choose equipment or resources for, and perform a first-hand investigation to determine the indicator organisms present in a local catchment area and from these deduce the chemical purity of water gather information on the source of water feeding into the local catchment area using maps or field trips gather information from secondary sources concerning the use and treatment of local water gather, process and present information from secondary sources to identify some major disasters involving water pollution

Water for Living GlossaryWordAccumulated sediment Artesian water Aquifier Bioaccumulatio n Bioassay Bore water Catchment area Cyanobacteria Dam Eutrophication Fertiliser Ground salinity Ground water Herbicide Indicator organism Lake Leaching Pesticide pH

Definition

WordRiver Solute Solution Solvent Surface Water Transpiration stream Turbidity Water pollution Water table Wetland

Definition

SolutionsYou can taste the salt in sea water but you cannot see the salt. The salt is said to be dissolved in the water. In this example, we have a solid substance (salt) dissolved in a large amount of liquid (water), giving salt water. In this situation, special names are used. The solid salt is called the solute The salt is said to be soluble in water The liquid water is called the solvent The salt water is called a solution Water solutions are called aqueous solutions Solutions are the most common type of mixture. A solution is formed when one substance (called the solute) dissolves in another (called the solvent). For example, when sugar is mixed with water, the solute is the sugar and the solvent is the water. We say that a sugar solution has been formed. One characteristic of solutions is that they are transparent (though they may be coloured) - no particles of the solute can be seen as they are too small and are spread evenly throughout the solvent. When a solution is made, the solute does not disappear. All of the solute added is still in the solution even though you cant see it. The total mass of a solution is always equal to the mass of the solvent plus the mass of the solute. Water is sometimes called the universal solvent because so many substances dissolve in it to form aqueous solutions. Besides aqueous solutions, there are many other solutions. This is because there are many other solvents. Solvents other than water are referred to as non-aqueous solvents. One example of a non-aqueous solvent is ethanol (alcohol). Ethanol will dissolve some solutes that water does not dissolve. There are some generalizations that can be made about aqueous solutions Solutions are mixtures of solute and solvent Solutions are homogeneous (uniform throughout) The extent to which a substance dissolves in water is called its solubility Substances, like sand, that do not dissolve in water are said to be insoluble Mixtures like sand in water are known as suspensions (because the sand doesnt dissolve in water) Solutes are not necessarily solids, they can also be liquids or gases. Liquid inks can dissolve, some are soluble in water, others are soluble in ethanol. Some gases, such as oxygen, dissolve to a certain extent in water. It is the dissolved oxygen in the waters of

the Earth that fish can use. Indeed without this dissolved oxygen, and gills to obtain it from water, fish would drown in water.

1. Label the diagram below:

2. Use the information from the diagram to complete the statements below. (a) solvent (b) 3. a) b) c) d) e) f) g) h) i) j) + + sugar solute

sugar solution (syrup)

Answer true or false to the following statements. All solutions are mixtures Sand is soluble in water A suspension is another name for a solution The substance dissolved to form a solution is called the solvent Water is the only solvent Oxygen is insoluble in water Ethanol is a non-aqueous solvent Sugar is insoluble in water Solutions are homogeneous Solutes can be solids, liquids or gases

4. In aqueous salt solution, water is called the _____, and salt is called the _____ 5. The term aqueous refers to a solution with as the solvent 6. A substance that dissolves in water is said to be _____

7. Sand in water is an example of a _____

8. Read the passage below and insert the correct word from the following list. Some words may be used more than once. dissolve(2) dissolved(3) evenly solvent(2) solution(4) mixes dissolves solute(2) liquid solutes

soluble

A __________________ is a special kind of mixture. A solution is formed when one chemical dissolves, or __________________ evenly into another. The most common type of solution is formed when a solid, such as copper sulfate __________________ in a __________________ such as water. A __________________ of copper sulfate is formed. In a __________________ no solid particles are visible. They have all mixed __________________ into the liquid. However, we can usually tell that the solid has __________________. A copper sulfate solution, for example, is blue. The blue colour due to the dissolved copper sulfate crystals is obvious. A sodium chloride __________________ looks just like water. However, if we taste it we know that salt has been __________________ in it because of the salty flavour. We call a liquid (like water) which will __________________ another chemical (like salt) a__________________ for that chemical. The salt, or any other solid which will dissolve in a

solvent is called a __________________. Water is a solvent for salt. It is also a solvent for copper sulfate. Both chemicals are__________________ by the water. Water is not a __________________ for sand because sand

will not dissolve in water. Copper sulfate and salt are both __________________ in water. That is, they both dissolve in water. However, neither of them is a __________________ for a liquid like methylated spirits because they do not __________________ in it. We say that copper sulfate and salt are __________________ in water, but insoluble in methylated spirits.

Syllabus dot point: perform a first-hand investigation to demonstrate that substances dissolve in water and identify the solute and solvent in each case

Experiment: Solubility of MaterialsAim: To determine which kitchen substances are soluble in water Materials: Measuring cylinder (50 mL) Salt Bicarbonate of soda Test tube rack 6 Test tubes Sugar Cocoa/Milo Tap water Spatula Flour Coffee Stirring rod

Method: 1. Place 40 mL of water into each test tube 2. Place a spatula full of each substance into different test tubes 3. Stir each test tube evenly for the same amount of time 4. Observe whether the substance being tested dissolves or not. Estimate how much of the teaspoon is dissolved. To do this, compare how much solid settles or floats. The more soluble the substance is, the less will settle or float. Record your results Results: Use the words solute and soluble to complete the headings of the table. What is the solvent in each test? Sol Salt Sugar Flour Bicarbonate of soda Cocoa/Milo Coffee Is it sol in water (yes/no/partially)

Discussion: 1. What was the independent variable? (the factor you changed on purpose each time)

2. What was the dependent variable? (the factor you measured as your results) 3. What variables were controlled? (the factors that were kept the same to make the experiment a fair test)

4. What factors or conditions may influence the solubility of a substance?

Conclusion: State which substances dissolved in water, which did not and which partially dissolved

Syllabus dot point: describe the importance of water as a solvent in the bloodstream cells transpiration stream

The Importance of Water as a Solvent Bloodstreamwater has a very important role in the human body because it helps to transport substances around the body in the blood. Substances transported include digested food, oxygen hormones and waste products. In the bloodstream, water is a solvent and many substances being moved y the blood are carried in solution

CellsIn cells water acts as a solvent for oxygen and many nutrients to organs. Wtaer acts as urea and carbon dioxide. It also facilities the transfer of gasses into cells.

Transpiration Stream

The movement of water throught the plant from root to leaf is referred to as the transpiration stream. Water acts as a solvent for mineral nutrients as the plant relies on water to carry nutirents up from the soil so that it can grow and develope.

Syllabus dot point: identify the relative amount of water in a variety of living things

Known Water Content of Living Things1. Use the information below to graph the percentages of water in different organisms. The information should be presented as a column graph. Organism Jellyfish Chicken Tomato Cabbage Apple Water Content (%) 98 66 92 91 84 Organism Potato Lettuce Human Banana Orange Water Content (%) 78 95 66 73 87

2. Fresh samples of a number of plant products were tested for moisture content. The results obtained are below. Complete the table by converting the water content of each plant tested to a percentage.

Type of Plant Peas Tomatoes Potatoes Apples

Moisture Content 35 g water in 50 g peas 9.5 g water in 10 g tomatoes 77 g water in 100g potatoes 63 g water in 75 g apples

Percentage Moisture Content (%)

3. Which of the following contains the most water? a 120 g tomato (92 % water) a 140 g banana (73 % water) a 135 g orange (86 % water) 4. Sophies mass is 60 kg. How much water does her body contain? (Assume 1 litre of water has a mass of 1 kg)

plan, choose equipment or resources for and perform a first-hand investigation to determine the amount of water present in a variety of fruits, vegetables and meat

Experiment: Water Content of Living ThingsIntroduction: You probably already know that organisms (living things) are made up of cells and that plant and animal cells are slightly different. One property that plant and animal cells share is that both kinds of cell are mainly composed of water. Aim: To determine the percentage, by weight, of water in various fruits, vegetables and meats Materials: Electronic Balance Incubator/oven 5 Crucibles 1 Evaporating dish Knife Chopping Board Lettuce Steak Potato Tomato Apple Orange

Method: 1. Place a crucible on the electronic balance and record the weight in the results table below. 2. Fill the crucible with small pieces of apple. Record the undried weight in the results table below. 3. Repeat steps 1-2 for the other food samples (Use an evaporating dish instead of a crucible for lettuce) 4. Place the samples in an incubator/oven at 40OC 5. Weigh each sample every day. To be sure that all the water has been lost from the cells you should continue warming and weighing until you obtain identical consecutive readings. This is known as obtaining a constant weight. Record the dried weight in the results table below. 6. Calculate the percentage of water present in each sample using the following formula Percentage weight of water = weight of undried food weight of dried food 100 weight of undried food x

Results:Food Weight of empty crucible/evaporating dish (g) 1.0 1.0 1.0 1.0 1.0 1.0 Weight of undried food (g) (mass of crucible with food mass of empty crucible) 70.10 15.3 15.34 14.08 15.33 15.45 Weight of dried food (g) (mass of crucible with food - mass of empty crucible) 44.46 5.74 4.84 3.15 9.62 8.44 Calculations (See step 6 in method) 25.64 9.6 10.5 10.93 5.71 7.01 % weight of water 36.3% 62.5% 68.4% 77.6% 37.3% 45.4%

Lettuce Steak Potato Tomato Apple Orange

Discussion: 1. What is the name of process by which the water is lost?The process is evaporation

2. Why do we use the procedure of heating to a constant weight?We should keep wieghting constantly till we constantly get the same wiegh

3. Compare your results with that of published data. (a) Are your results accurate?yes it is very accurate as we repeated it

(b)Explain any difference between your results and that of the published dataMy results may differ from the resukts of a published data because as they may have done it a different way

Conclusion: Place the fruits, vegetables and meat in order from highest water content to lowest water contentthe fruits vegetbles and meat from highest water content to lowest were tomato, potato, steak, orange, apple& lettuce

Syllabus dot point: discuss ways in which plants optimise water uptake

Optimising Water Uptake in Plants- Plants have thousands of root hairs that increase the srface area for water aborption. Root hairsensure close contact with soil to increase the rate of water uptake. They have large deep penetrating root systems. - Plants grow sparsly to reduce competition for water areas where water is scarce. - Leaves slope steeply upward to catch rain and direct the rain to dense shallow

Syllabus dot point: discuss ways, using examples, that plants reduce water loss such as: thick outer coating (cuticle) on leaves reduced leaves dropping leaves in times of drought

How Plants Reduce Water Loss A waxy cuticle (a cuticle is the outside coating) This surface reflects light from the sun. This reduces heat on the leaves which prevents water from evaporating from the leaves Reduced leaves and dropping leaves in times of drought Fewer leaves means less transpiration (movement of water from the root to the leaf) so water is conserved Thin and needle like leaves This conserves moisture by reducing water loss by transpiration Leaf curling The leaf curls so that the stomata are enclosed in a tight area. (Stomata are tiny pores found on the leaves of plants. Water can move out of the plant through these pores). This reduces the ability of water vapour to leave the area and thus reduces water loss. Sunken stomates The stomata are located in sunken grooves which results in humid air being concentrated above the stomate, which reduces water loss Water storage Water is stored in trunk, leaves or roots Hanging leaves Leaf hangs down rather than being held horizontal to the ground, which reduces exposure to sun Hairy leaves Hairy surfaces on under surface reduce air movement and increase humidity over stomates, reducing water loss

Question Match the numbers in the left hand column of the table with the letters in the right hand column. Use your results to decode the mystery word below, which is a term used to describe plants that are adapted to areas where water is in short supply. 1x 2E 3R Adaptation 1. Shiny or hairy leaves 2. Waxy cuticle on leaves such as eucalypts 3. Extensive root system 4. Leaves reduced to small spines or scales, sometimes with the stem taking over the role of photosynthesis, leaves hanging vertically 5. Sunken stomates, stomates reduced in number or stomates on undersurface of leaf only 6. Closure of stomates during the hottest part of the day 7. Leaves rolling, curling up or falling during dry conditions 8. Rapid life cycle 4o 5p 6H 7Y 8T 9S

How does this adaptation allow the plant to conserve water? E. Provides a waterproof coating to reduce water loss from the leaf by evaporation S. Allows the plant to store large quantities of water P. Reduces evaporation of water from stomates because they are reduced in number or partly enclosed by the leaf H. Prevents water being lost by evaporation during the warmer hours of the day Y. Behavioural adaptations that reduce the surface area of leaves exposed to drying conditions X. Reflect heat from the plant, so reducing water loss by evaporation R. Increases the plants ability to draw water from the soil O. Reduces the surface area of the leaf and

9. Swollen stems

reduces water lost through stomates during photosynthesis T. Allows the plant to flower and produce seeds when water is available to it

Syllabus dot point: perform a first-hand investigation to identify adaptations of some plants that assist in reducing water loss

Experiment: Adaptations in Plants That Assist in Reducing Water LossBackground information: Adaptations in the roots, stems, leaves and flowers of native Australian plants help them to conserve water. In this investigation, a variety of Australian plants are available for examination so that first hand information may be gathered about them. Aim:

Materials: A number of plants that have adaptations to minimise water loss, for example casuarina, acacia/wattle, cacti (reduced leaf surface), eucalyptus species and hakea, grevillia and banksia species, spinifex grass (hairs rolled inwards) Hand lenses Plant slides Microscope

-

Method: 1. Collect a variety of leaf samples from Australian native plants from around the school 2. Carefully observe each of the plant structures that minimise water loss using a hand lens eg waxy cuticle, sunken stomata, reduced numbers of stomata, reduce leaf surface, hairs on the leaf surface 3. Make a labelled diagram of each leaf highlighting the appropriate structures and state how each structure helps to minimise water loss 4. Examine the plant slides under the microscope to observe sunken stomates 5. Compare and discuss results with other students in the classroom Discussion 1. Prepare a table to summarise the adaptations you have observed

2. Identify two safe work practices needed during this investigation

Experiment: Adaptations in Plants That Assist in Reducing Water Loss

How adaptation minimises water loss

Adaptation:

Diagram:

Plant:

How adaptation minimises water loss

Adaptation:

Diagram:

Plant:

How adaptation minimises water loss

Adaptation:

Diagram:

Plant:

Experiment: Adaptations in Plants That Assist in Reducing Water Loss

How adaptation minimises water loss

Adaptation:

Diagram:

Plant:

How adaptation minimises water loss

Adaptation:

Diagram:

Plant:

How adaptation minimises water loss

Adaptation:

Diagram:

Plant:

Syllabus dot point: discuss ways, using examples, that animals reduce water loss such as: excrete uric acid instead of urea nocturnal behaviour reduced activity lying in the shade burrowing underground

How Animals Reduce Water Loss

Syllabus dot point: gather, process and analyse information to identify the different ways in which a range of terrestrial animals reduce water loss

How Animals Reduce Water LossComplete the following table by giving an example of an adaptation to conserve water for each animal. Include an explanation of why each adaptation is effective in reducing water loss. Animal Adaptation How water is conserved

Hopping mouse

Wombat

Possum

Kangaroo

Lizard

The Water CycleYou have no doubt read or learnt about the water cycle previously. The diagram below shows a simple form of the water cycle. The many forms of water and the processes that link them are shown. Some books or reference sources will refer to this as the hydrological cycle. This is just another name for water cycle. The term 'water' comes from the Greek word hydra so anything relating to water can have hydra or hydro in the term. Two examples of this is hydro-electricity, as electricity is generated by water and hydration is the process of adding water to a substance. You will now use coloured pencils to colour in sections of the water cycle above. This will help to better understand the processes involved. a) clouds, snow and glacier yellow b) sun orange c) trees green d) transpiration and evaporation light blue e) precipitation (rain) purple f) percolation, ground water, ocean and lakes dark blue g) run off and rivers red. Draw a flow chart including the following terms in the order they appear in the water cycle: ground water; evaporation; percolation; precipitation.

Experiment: Representing the Earths WaterAim: To represent and compare the types and respective quantities of the Earths total water supply. Materials: 1 L graduated beaker (with 1 L of water) 10 and 50 mL graduated cylinders 100 mL beakers (3) wax paper (one piece 5 cm square) 20 g NaCl stirring rod dropper texta

Method: 1 Label the beakers: the 1 L beaker A and the three 100 mL beakers B, C and D. 2 Fill beaker A with 1000 mL of water. 3 Pour 28 mL of water from beaker A into a 100 mL beaker labelled B. 4 Add 20 g of NaCl to beaker A. (This now represents the salt water in the Earths oceans unfit for drinking.) 5 The water in beaker B represents all the Earths fresh water. Pour 6.5 mL from beaker B into beaker C. The water in beaker B now represents inaccessible freshwater tied up in glacier and polar icecaps. (This could be put in the freezer.) 6 Pour 3.4 mL from beaker C into beaker D. The water in beaker C now represents inaccessible ground water. 7 The water in beaker D now represents the entire supply of fresh water on the Earth, but much of this water is polluted or otherwise unavailable for human use. Use the dropper to remove 5 drops of water from beaker D and place these on the wax paper. This water represents the water available for drinking (1 mL = 20 drops). Questions: 1 Draw diagrams to show the beakers (and wax paper) and their contents. Label each with the type of water represented.

Draw a column graph to represent these figures.

3 Comment on the varying amounts and types of water.

4 What are the implications or significance of these quantities for: a national government leaders?

b farmers? c local government councils? d individuals?

Syllabus dot point: outline types of surface and ground waters in the hydrological cycle such as: bore water artesian water the water table dams rivers lakes wetlands cave environments

Types of Water1.Surface Water This water occurs on the surface of the Earth and is easy for people to access. It includes both fresh and salt water (a) Rivers: A moving body of fresh water (b) Dams: An artificial (man made) body of surface water (c) Lakes: A naturally occurring body of surface water (d) Wetlands: A continually waterlogged area such as billabongs, swamps, salt marches, mudflats and mangroves

2.

Ground Water This includes any water that is beneath the Earths surface Water can be stored under the ground in rocks. Rocks that can store water are called porous rocks. Other rocks do not store water but water can pass through them. These are called permeable rocks. Rocks that are both porous and permeable are called aquifiers. When ground water that is flowing through aquifiers becomes trapped and is confined under pressure between layers of rock and is unable to move it is called artesian water. It naturally rises to the surface under its own pressure. Bore water is underground water that must be pumped to the surface if it is to be used. Water from wells is called bore water. The upper surface of ground water is called the water table Water can also be found in underground rivers and pools in cave environments Questions 1. Identify the different types of water and the water table labelled a-e

(a) (b) (c) (d)

(e)

(e)

2. Look at the diagram below. In this diagram use an arrow to show where would you find: (a) Artesian water (b) Bore water

3. Use the information in the text you have just read to match the following water terms with the appropriate explanations. artesian water river water table dam underground lake bore water lake wetland a moving body of surface water a continually water logged area where the water table meets the surface underground water that must be pumped to the surface if it is to be used a naturally occurring body of surface water, formed where the water table meets the surface porous or permeable underground rock that can hold water the upper surface of ground water an artificial body of surface water a body of underground water, usually within a cave

aquifer

underground water that naturally flows to the surface

4. The following diagram provides a model to show the distribution of the worlds water. Examine this model and use the information it contains to answer the questions below. Distribution of the Worlds WaterFresh water 3 %

All water

Oceans 97 %

Fresh water

Easily accessible surface fresh water 1 % Ground water 20 % Icecaps and glaciers 79 %

Easily accessible surface fresh waterAtmospheric vapour 8 % Water within living organisms 1 %

Rivers 1 %

Soil moisture 38 %

Lakes 52 %

(a)

Identify the following percentages:

(i)

percentage of the worlds water that is fresh

(ii) percentage of easily accessible surface fresh water that is not from rivers or lakes (iii) percentage of the worlds water that is in ground water (b) State whether each of the following statements is true or false:

(i)

Most of the worlds water occurs in the oceans

(ii) Most of the worlds fresh water occurs in lakes (iii) Eight per cent of the worlds water occurs as vapour in the atmosphere (iv) There is more water underground than in all the rivers and lakes of the world combined

Syllabus dot point: process information from secondary sources to map the location and type of surface and ground water in the local area

Mapping Water in the Local Area (Liverpool)

Use a street directory to map the location of the creeks, lakes, river and bay below. Make sure you complete the key. KeyCabramatta Creek Prospect Creek Lake Gulawarna Dhurawal Bay Floyd Bay Lake Moore Chipping Norton Lake Georges River

Syllabus dot point: discuss the effects of water pollution and ground salinity on the continued supply of fresh water to living things and provide examples of these occurring in Australian environments Syllabus dot point: identify possible solutions to environmental problems associated with the use of ground water

Problems With Ground WaterGround water represents a significant component of the total global freshwater reserve. It is by far the largest reservoir for drinking water and a as such signifies an important natural resource that needs to be carefully managed to ensure sustainability. Ground water comes from rainwater soaking its way through the soil into the underlying rocks, where it slowly makes it way downhill under the pull of gravity around 10 metres per year on average. The movement of ground water is also strongly influenced by the types of rocks it encounters: porous rocks, such as sandstone, act as a reservoir for groundwater, where as non-porous rocks, such as shales, act as a barrier to it. The quality of groundwater can be naturally highly variable. Some aquifers geological formations that store groundwater release water that is very clear and low in dissolved minerals, such as salt. Others have very murky or highly saline water, making it unsuitable without secondary treatment. Water quality can even be variable within the one aquifer, with central areas being replenished more rapidly than the more stagnant margins. Saltwater Intrusion Saltwater intrusion occurs when the human removal of ground water causes salt water to move into parts of an aquifer that previously held fresh water. This typically occurs in aquifers adjacent to the sea that are not sealed by an overlying layer of clay. Normally, fresh groundwater seeps its way downhill through the aquifer until it discharges into the sea water. However if too much of this fresh groundwater is removed for human uses, such as for drinking, irrigation and industry, the drop in water pressure acts like a straw to draw salt water into the aquifer. The water being withdrawn from the aquifer becomes increasingly saline and unsuitable for most uses. This form of saltwater intrusion is believed to have occurred in the groundwater around Botany Bay, with the unregulated removal of groundwater by various industries in decades past.

(a) Water usage balances rainwater added to aquifer (b) If too much water is withdrawn from the aquifer, the water becomes increasingly saline and unsuitable for most uses. An example of the sustainable use of groundwater can be seen around Stockton Beach, north of Newcastle. Fresh groundwater is removed from this unsealed aquifer to form part of the water supply for Newcastle and the surrounding areas. By carefully studying the aquifer and its rates and patterns of flow, water authorities know how much water they can safely remove without risking intrusion by sea water.

Saltwater intrusion can also occur without the involvement of sea water. If too much water is removed from the central part of an aquifer, the more stagnant and saline water of the outer margins can be drawn into the centre. Ground water used for cotton irrigation around the Mooki and Namoi rivers of Northern New South Wales is becoming increasingly saline in this way. This impacts on soil fertility and crop yields. Pollution The pollution of groundwater is a serious problem. Most pollutants from human activities move through aquifers at even slower rates than water, meaning any contamination will not just quickly flush away. Industries are now regulated to try and prevent the pollution of groundwater. Unfortunately, unregulated activities in the past are the source of much of the contaminants now detected in groundwater around the country. If safe practices are not in place, groundwater can be polluted by a variety of activities.

Industry Waste disposal: Water and sewage Garbage in landfill Hazardous wastes

Potential Pollutants Disease-causing viruses and bacteria, such as faecal coliforms and enterococci; nutrients; heavy metals; ammonia, chlorides and sulfates; organic compounds, such as dioxins and PCBs Nitrogen, phosphate and potassium from fertilizers; pesticides; herbicides; heavy metals; and bacteria Petroleum hydrocarbons, benzene and ethyl benzene Acidic water; iron; sulfates; organic materials; heavy metals; and hazardous substances, such as cyanide (used in concentrating gold from crushed rock)

Agriculture Chemical, petroleum and transport

Mining

The treatment of polluted groundwater is very expensive and time consuming. One method that has been attempted is to pump polluted water to the surface where it can be treated to remove the contaminants. This cleaned water is then pumped back into the aquifer. An alternative method involves the use of microbes to break down pollutants into less harmful forms. This can be done within the aquifer itself by

either introducing microbes or encouraging the growth of microbes already present by adding nutrients and/or oxygen to the aquifer. This method can be used to treat contamination by hydrocarbons, such as petroleum products.

Use of Ground WaterDescription (cause) Environmental Problem Saltwater Intrusion

Impact (effect)

Solution

Pollution

Catalyst Special: Groundwater 15/3/071. Approximately what percentage of the worlds drinking water is groundwater.

2. Describe the current sources of drinking water in Western Australia.

3. Describe the problems facing the supply of water in Western Australia.

4. Outline some of the problems for ecosystems when groundwater is overused.

5. Discuss one of the solutions proposed to recharge aquifers in Western Australia.

6. Discuss how the Botany Sands aquifer can be used to support Sydneys water supply.

Syllabus dot point: process, analyse and present information from secondary sources to assess human impact on one aquatic ecosystem or water source in Australia and identify some consequences of this impact and one possible rehabilitation technique

SalinityMuch of Australias wealth comes from agriculture. The success of our agricultural industries depends very much on the quality of the land used for crop and livestock production. In countries throughout Africa much of the land used for agriculture has been overused to a point where output from the soil is extremely low the land has become degraded. Land degradation can be caused in many ways. It can occur naturally but, more commonly, it results from misuse of the land by humans. One common form of land degradation is salinity, which is an increase in the level of salt in the soil. In many farming areas of Australia the quality of the land being used for agriculture is affected by salinity. It is estimated that salinity reduces the value of production of Australian agriculture by $100 million each year. Fortunately, farmers in Australia have available to them the technology and finance to find ways of overcoming the salinity problem. Salt can be found naturally in nearly all things in nature rocks, soil and water. Salinity becomes a problem when the level of salt increases above what would normally be expected in an area. The level of salinity in an area influences the types of crops or pastures grown on farms.

How did Salinity Become a Problem? At certain depths below the ground level, soil is fully saturated (or soaked) with moisture. This zone or area of saturated soil is called the ground water. The upper limit of ground water is known as the water table. If the ground water has a high level of salinity and the water table rises and comes into contact with the roots of plants, their growth can be affected and some plants may die.

There are two main forms of salinity: 1. Salinity caused by over irrigation of farmlands. Too much water on crops or pastures causes the soil moisture to increase, which may cause the water table to rise and come into contact with plant roots. 2. Dryland salinity. This is usually the result of clearing trees and shrubs or overgrazing. With fewer plants, less moisture is released back into the atmosphere (the process of transpiration) and so more moisture soaks into the soil. As the ground water flows to low points or depressions in the land, a build-up of salt occurs at these depressions. The built-up salt may come up to the surface as patches of very salty soil. Dryland salinity is a problem in the wheat and sheep producing lands of south-west Western Australia and parts of North Africa, where much of the natural vegetation of this area has been cleared.

Case study: Salinity in Australias Murray Valley

silt) carried by the Murray River and other streams. The ground water under the Murray Valley has a high level of salinity due to this salt-rich layer below the surface. When large areas of the valley were irrigated, increased water soaking into the soil caused the water table to rise. This brought the salty ground water into contact with the roots of trees and plants, and in some cases right to the surface. The salty ground water not only damages and in some cases kills plants, but it also flows towards the lowest point. The lowest point may be a creek or river, which eventually finds its way into the Murray River. This creates a further problem because Adelaide obtains most of its water from the Murray. Water for household use in Adelaide has four times more salt in it than Sydneys water supply. Dealing with the salinity problem In 1989 the Commonwealth and state governments agreed to a management plan for the Murray Valley known as the Salinity and Drainage Strategy. Under this plan the Murray Darling Basin Commission has set up a number of projects aimed at reducing the causes and effects of salinity. It was necessary to come up with a number of different types of projects, because the causes and effects of salinity differ across the Murray Valley. Some of the different methods being used to reduce salinity are as follows: In grazing areas in the west of the Murray Valley farmers are being encouraged to replant natural vegetation in areas affected by dryland salinity and to increase plant growth by reducing the sizes of herds. In irrigation areas, ground water is being pumped out and stored in basins. This lowers the water table. The stored water is allowed to evaporate and the salt that is left is harvested for use in industry. Irrigation framers are being encouraged to use water more wisely by paying a higher price for their water. In the past, farmers received water at a price that was much lower than the cost to the government of providing it. Local communities are being educated about sustainable agriculture techniques. Membership of local Landcare groups is encouraged

The Murray Valley is one of Australias most important agricultural areas. It produces fresh and dried fruits, rice, wine, vegetables, beef and dairy products. Irrigation has played an important role in the development of agriculture in the Murray Valley. Towns such as Shepparton and Mildura in Victoria, Deniliquin and Wentworth in New South Wales and Berri and Renmark in South Australia grew mainly because of irrigation agriculture. When irrigation was introduced to the Murray Valley, however, few people realised that salinity would be a problem. What was also unknown in the early days was that the Murray Valley was once covered by sea water. Millions of years ago, the sea extended from the area that is now the mouth of the Murray, near Adelaide, inland into New South Wales and Victoria. When the sea level fell and the inland sea was gone, a thick bed of salty se sand was left in its place. In addition, winds blowing from the Great Australian Bight carried large amounts of salt inland and deposited them. Over the years the salt was covered by sediment (sand and

Salinity1. What is salinity?

2. Salinity can be classified into different types Describe: (a) Dry salinity

(b)Irrigation salinity

3. Identify an Australian aquatic ecosystem affected by salinity. Describe the area and what it is used for

4. Describe the human activities (both past and present) that have caused salinity in the area

5. Outline the impact of this human activity. Describe why salinity is a problem for: (a) farmers

(b) people in Adelaide

(c) the Australian economy

6. Outline TWO measures taken to manage or rehabilitate the area

Syllabus dot point: analyse information from secondary sources to outline the relationships between rainfall and types of Australian ecosystems

Australias EcosystemsHave you been to the Australian outback? If so, you would have noticed a large difference between the plants in the outback compared to those on the coast. What do you think causes these ecosystems to be so different? If you answer was the amount of rain they receive, you were correct, however this is only one factor affecting ecosystems. Others are soil, aspect, topography, sunlight, cloud cover, temperature, animals and many more. In this section, you will learn about the different ecosystems of Australia and their various water requirements.

1. Use the diagrams of Australias ecosystems and Australias annual rainfall to determine what rainfall is mostly associated with each ecosystem (low, medium and high). Desert Grassland Shrubland

Woodland Forest 2. The table below outlines the characteristics for each type of ecosystem shown in the diagram. Fill in the missing information in the annual rainfall column for each ecosystem. Ecosystem desert grassland shrubland woodland forest (rainforest and sclerophyll forest) Vegetation saltbush grasses bluebush spinafex grasses herbs mallee mulga brigalow box trees colabah shrubs jarra bluegum stringy bark karri Annual rainfall Temperature high temperate or tropical high temperate or tropical warm temperate

3. Fill in the final word(s) for each sentence. a) A typical forest plant is b) Woodlands temperature is c) Spinafex, herbs and grasses all belong to a d) Desert ecosystems mainly exist in the middle of e) A forests annual rainfall is d) Two vegetation types of deserts are e) Coolabahs and box trees belong to f) Rainfall in woodland is g) An ecosystem that requires low rainfall with a temperate or tropical climate is h) Jarra and stringy bark require rainfalls that are 4. Use the information above on Australias ecosystems to complete the following exercise. a) Colour in or shade the areas of Australia below that match each of the ecosystem types. b) List the common plant species found in each ecosystem in the boxes provided. c) Record the rainfall for each box. d) Record the temperature for each box. The desert ecosystem has been done for you as a guide.

Syllabus dot point: outline one local, State or Federal Government policy on water-related issues in relation to increasing problems with water supplies across NSW

www.sydneywater.com.au

Water Wise Rules1. (a) When were level 1 water restrictions introduced and why?

(b) When were level 2 water restrictions introduced and why?

(c) When were level 3 water restrictions introduced and why?

2. We no longer have water restrictions but water wise rules. Outline these rules and the reason for their introduction.

3. Which level of government (Local, State or Federal) has imposed the restrictions? 4. To which areas do the restrictions apply?

5. What are the consequences for NOT following the restrictions?