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Human life depends on a tiny fraction of the world’s water, which is constantly recycled between the oceans, land and atmosphere. Freshwater reserves are unevenly distributed, which creates water-rich and water-poor regions (in which shortages occur). Millions lack access to both safe drinking water and improved sanitation facilities and are affected by water-borne diseases as a result. Improving water quality and sanitation for the poorest requires sustainable development that uses appropriate technology and the expertise of local communities. Diseases contracted from contaminated water such as malaria and cholera are being effectively controlled in many areas. Water pollution such as marine oil slicks is a worldwide environmental issue and many countries have responded by introducing laws and agreeing to international conventions to prevent it.

CONTENTS a) Global water distribution

h) Managing pollution of fresh water

b) The water cycle

i) Managing water-related disease

c) Water supply

j) Case study: Environmental impacts of the Three Gorges Dam

d) Water usage e) Water quality and availability f) Multipurpose dam projects

k) Case study: Cleaning up the River Rhine

g) Causes and impacts of water pollution

LEARNING OBJECTIVES Describe the distribution of the Earth’s water. Describe and interpret the water cycle. Describe the sources of fresh water used by people. Describe the different ways fresh water can be used. Compare the availability of safe drinking water (potable water) in different parts of the world. Describe and evaluate multipurpose dam projects. Describe the sources of water pollution.

Describe and explain the impact of pollution of fresh water on people and on the environment. Describe and explain strategies for improving water quality. Describe the life cycle of the malaria parasite. Describe and evaluate strategies to control malaria. Describe strategies to control cholera. Describe the impact of a named multipurpose dam scheme. Describe the causes, impact and management of pollution in a named body of water.


4

Water and its management


GLOBAL WATER DISTRIBUTION The world’s total water supply amounts to approximately 1386 cubic metres. Figure 4.1 (first bar) shows that over 97 per cent of this water is saline and mostly located in the oceans. Only a tiny proportion of this total (2.5 per cent) is the fresh water that humans require to sustain life (middle bar). Of this fresh water, over two-thirds is locked up in glaciers and ice caps and almost all the rest is stored as groundwater (water in the soil or held in pores of rock). Surface fresh water (third bar), which is the source of the water people consume around the world, represents only slightly more than 1 per cent of the total fresh water available (0.0067 per cent of the Earth’s total water). Almost 90 per cent of the planet’s fresh water is stored in ice and lakes with the remaining 10 per cent being held in five other main stores. Considering that rivers are the main source of water for the world’s population, it is clear that human life depends on just 0.0002 per cent of the planet’s total water. Fresh water 2.5%

Other saline water 0.9%

Oceans 96.6%

Total global water

Surface/other fresh water 1.2%

Groundwater 30.1%

Glaciers and ice caps 68.7%

Ground ice and permafrost 69.0%

Fresh water

Surface water/other fresh water

Atmosphere 3.0% Living things 0.26% Rivers 0.44% Swamps, marshes 2.6% Soil moisture 3.8% Lakes 20.9%

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WATER AND ITS MANAGEMENT

∆ Fig. 4.1 The locations of water on Earth.

THE WATER CYCLE The volume of water on Earth has remained much the same for billions of years because it moves continuously and very efficiently around the world. The water cycle, driven by the sun’s energy, also known as the hydrological cycle, describes this movement of water between the oceans, the land and the atmosphere and is summarised in Figure 4.3. rThe sun heats the water held on the Earth’s surface in oceans, seas and lakes. Some of this water is turned into water vapour (water in the form of an invisible

∆ Fig. 4.2 Victoria reservoir, Sri Lanka – rivers are the world’s most important source of fresh water.


condensation

condensation vapour transport evaporation

precipitation

evaporation

transpiration by plants

evaporation precipitation

surface run-off percolation through rocks

river lake land ocean

groundwater flow

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gas) through the process of evaporation. Some water vapour is added by plants through the process of transpiration (the evaporation of water moving through the plant from its leaves). rThis warm moist water vapour rises because it is less dense than the surrounding atmosphere. As it rises the air cools and the water vapour condenses (turns back into water droplets) into clouds, which air currents transport around the globe. ∆ Fig. 4.4 Plants intercept some precipitation. rThese water droplets then fall as precipitation (rain, snow, fog, mist, dew) onto the land and oceans. Some will be intercepted to provide the water that plants and humans require for their survival, for example, taken up by plant roots or collected in reservoirs. Water will also be captured and stored in freshwater lakes or in ice caps or glaciers. rMost of the precipitation, however, will flow across or run off the surface of the land and into rivers or infiltrate the ground through percolation. Rivers return the water to the oceans. Some of ∆ Fig. 4.5 Ice caps such as the Greenland ice cap will the water that seeps underground through capture and store some precipitation. infiltration will be stored in aquifers (layers of permeable rock that absorb water) while the remainder will eventually seep back into the ocean as groundwater flow.

THE WATER CYCLE

∆ Fig. 4.3 A summary of the water cycle.


many also have multiple showers, baths and toilets in additional bathrooms. Millions of litres of water are also used each year to water gardens and fill ponds. Outside of the home, many leisure and convenience activities such as swimming pools or car washes also consume large quantities of water.

∆ Fig. 4.16 A petrochemical manufacturing plant at Antwerp, Belgium.

∆ Fig. 4.17 Cooling towers of a nuclear power station at Doel, Belgium.

WATER QUALITY AND AVAILABILITY There are 42 800 billion cubic metres of freshwater reserves available on Earth, which amounts to an average allocation of 5925 cubic metres per person a year. However, this figure assumes an even distribution of freshwater reserves across all of the regions and countries of the world, which is far from the case, as seen in Table 4.3. Region

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WATER AND ITS MANAGEMENT

Latin America and Caribbean East Asia and Oceania Europe and Central Asia North America Sub-Saharan Africa South Asia Middle East and North Africa

Water reserves Available water reserves per (billions cubic metres) person per year (cubic metres) 13 867 22 162 10 096 4525 7071 7866 5668 15 993 3883 3987 1982 1152 231 554

∆ Table 4.3 Distribution of global water reserves by region.

Because of this uneven distribution, the world has water-rich and water-poor regions. South America and the Caribbean, with 500 million inhabitants or 8 per cent of the world’s population, has 31 per cent of the world’s freshwater reserves. North America is another water-rich region, with 13 per cent of the freshwater reserves but only 7 per cent of the planet’s residents. In fact just two countries – Brazil and the United States – possess 25 per cent of the world’s water reserves. Compare this with Asia where over 4 billion people live (60 per cent of the world’s population) but only have access to 28 per cent of the world’s freshwater


resources. The most water-poor regions of the Middle East and North Africa contain only 0.5 per cent of freshwater reserves and as home to 5 per cent of the globe’s population, have the lowest available water reserves per person in the world. Such an uneven distribution of water resources means that inevitably some countries experience either physical or economic water shortages, while in others there is no scarcity at all, as Figure 4.18 shows.

Water scarcity extreme physical water shortage physical or approaching physical water shortage economic water shortage little or no water scarcity no data

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A physical water shortage occurs in a country when all available reserves have been exploited and demand continues to rise. An economic water shortage means that people have insufficient water even though there are adequate water reserves available. This is often the case in the world’s lowest income countries, which commonly do not possess the capital or technology to invest in fully exploiting their water reserves. This is true in many Sub-Saharan countries of Africa. Angola is ranked by the World Bank as 116th in terms of wealth out of 183 countries and Angolans have an average life expectancy of just 50 years. Despite having potential water reserves of over 6000 cubic metres per person, less than 10 per cent has so far been exploited. Because water is the world’s most valuable natural resource, serious disagreements and even conflicts can occur between countries when its ownership and use is disputed. When in 2013 Ethiopia began construction of the Renaissance Dam project on the Blue Nile, ∆ Fig. 4.19 Cachoeiras waterfall, Angola. one of the major tributaries of the River Nile, the government of Egypt threatened to declare war. The River Nile (Figure 4.20) is fed by waters from 11 countries, and 40 million

WATER QUALITY AND AVAILABILITY

∆ Fig. 4.18 Water scarcity by country.


End of topic checklist Key terms accessibility, acid rain, agriculture, aquifer, artesian, bioaccumulation, catchment, climate change, commercial, condensation, culture, desalination, desert, disease, distribution, domestic, drought, ecology, economic development, economic recession, ecosystem, environment, erosion, eutrophication, fresh water, genetic engineering, greenhouse gas, groundwater, habitat, hazard, history, improved sanitation, improved water source, indigenous, industrialised, industry, infrastructure, location, manufacturing, migration, multipurpose dam, natural resources, nongovernment organisation, photosynthesis, pollution, potable water, precipitation, primary consumer, raw material, recycling, religion, renewable energy, run-off, rural, secondary consumer, sedimentation, services, subtropical, surface water, sustainability, tertiary consumer, trade, transport, trophic level, tropical, urban, water cycle, water-poor, water-rich, water table

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WATER AND ITS MANAGEMENT

Important vocabulary aid, algae, antibiotic, aquatic, arable, archaeological, atmosphere, bacteria, basin, brackish, canyon, capital, charity, commodity, compensation, compost, consumer, contamination, convention, coral, dam, dehydration, deoxygenation, depletion, detergent, diagnosis, directive, disinfected, dispersant, earthquake, economic, electricity, elimination, endangered, energy, eradication, estuary, evaporation, export, extraction, faecal, fault, fertiliser, flood, glacier, hormone, hydraulic, hydroelectric, hydrologist, ice cap, impact, impermeable, infection, infiltration, insecticide, intensive, irrigation, joint, lake, landscape, latrine, law, leaching, lock, malaria, migration, mining, mobility, mosquito, mutation, navigation, nuclear, nutrient, ocean, organic, parasite, pathogen, percolation, permafrost, permeable, permit, pesticide, physical, phytoplankton, porous, productivity, prophylaxis, rapids, regulation, rehydration, remote, replenish, reserve, reservoir, resettlement, resistance, resistant, river, saline, saturated, season, seasonal, sedimentary, sewage, silage, silt, sludge, slurry, soil, spawn, spring, subsistence, tax, technology, toxins, transmission, tributary, turbine, vaccine, valley, waste, weir, wetland

During your study of this topic you should have learned:

â?? All human life depends on a tiny fraction of the world’s total water. â?? The water cycle describes the constant movement of water between the oceans, land and atmosphere.


End of topic checklist continued ❍ Groundwater and surface water are the two main sources of water for human use. ❍ Desalination involves removing dissolved salt from sea and brackish water to make it fit for human consumption.

❍ Water consumption varies hugely between different regions of the world. ❍ The level of economic development in a country is the main factor affecting water consumption.

❍ Freshwater reserves are not distributed evenly across the world, which means that some regions can be defined as water-rich and others as water-poor.

❍ Water shortage can be the result of physical or economic factors. ❍ One in ten people do not have access to potable or improved drinking water and this can be the cause of serious water-borne diseases.

❍ Countries with poor access to potable water also often have poor sanitation, which increases the risk of disease.

❍ Multipurpose dams such as the Three Gorges Dam in China are constructed for a range of reasons, including providing energy, irrigation and drinking water and improving river navigation.

❍ Multipurpose dams can have positive and negative economic, social and environmental impacts.

❍ Domestic waste and industrial and agricultural practices are the main sources of water pollution.

❍ Supporting appropriate and sustainable developments in the poorest countries

of the world is the most effective way of improving sanitation and water supply.

❍ Oil spills such as the Deepwater Horizon blowout can have catastrophic ecological and economic consequences, and disaster planning and management is required to minimise these effects.

The questions for Section 4 start on page 247.

119

but a range of measures have now been introduced to combat their transmission and achieve eradication in the future.

WATER AND ITS MANAGEMENT

❍ Many countries now have strict controls and laws to prevent water pollution. ❍ Water-related diseases such as malaria and cholera kill millions of people a year


Despite these threats the number of wild mountain gorillas has increased over the past 20 years and now stands at 880 individuals. This is the result of the success of the International Gorilla Conservation Programme (IGCP), which has been working since 1991 to ensure its long-term survival. Particularly effective conservation measures include:

t Providing funding to increase both the

number and improve the equipment of anti-poaching patrols in protected forest areas. This has increased the coverage and duration of patrols and reduced significantly the number of animals being poached.

∆ Fig. 9.40 Rangers at Volcanoes National Park, Rwanda, which has the largest population of wild mountain gorillas in the world.

t Organising and funding teams to collect

hunting snares and bush meat traps from the forest.

t Setting up rehabilitation centres where

orphaned or rescued young gorillas can be prepared for a return to the wild.

t Increasing the area of national parks to

protect more forest and undertaking afforestation work in cleared areas to allow lost habitat to regenerate.

∆ Fig. 9.41 Cleared forest now used as farmland adjacent to Volcanoes National Park, Rwanda.

t Better management of visitors and tourists to

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NATURAL ECOSYSTEMS AND HUMAN ACTIVITIES

minimise the likelihood of disease transmission by ensuring that they are always more than seven metres from gorillas.

t Working with local communities to increase

understanding of gorillas and support for their protection and conservation. Teachers and pupils have been given information books about gorillas, and rangers run awareness and conservation programmes in local schools.

∆ Fig. 9.42 Male ‘silverback’ mountain gorilla in the forest of the Virunga mountains.

t Encouraging ecotourism and investing profits from visitors viewing gorillas back into the local community, for example, building new schools and clinics. As a result, people have come to see the monetary value of conserving the forest habitat and actively protecting gorillas.

∆ Fig. 9.43 Developing ecotourism is an important aspect of mountain gorilla conservation programmes.


CASE STUDY

UNESCO BIOSPHERE RESERVE, NORTH DEVON, UK

North Devon’s biosphere reserve covers much of the ecosystem created by the catchment areas of the Rivers Taw and Torridge and the offshore marine areas stretching out to Lundy Island in the Bristol Channel. Located in the county of Devon in the UK, it is home to about 150 000 people and includes protected landscapes of great ecological and landscape value. However, the majority of the area is ∆ Fig. 9.44 North Devon Biosphere logo. where people live and work. Lowland farmland is the most important land use.

Br istol

Channel

Biosphere Region Zones

■ Buffer ■ Core ■ Transition

Ilfracombe Lundy Island

Minehead

North Devon Biosphere Buffer Zone

Braunton Burrows

Barnstaple Bay

SOMERSET Exmoor National Par k

Barnstaple

(Bideford Bay)

w Ta

Northam Bideford

ge rid Tor

D E V O N Tiverton

Nature Improvement Area Holsworthy

0

∆ Fig. 9.45a The UNESCO Biosphere Reserves of the United Kingdom.

1 km

Exeter

C O R N WA L L

Dar tmoor National Pa r k

∆ Fig. 9.45b North Devon biosphere reserve.

233

The core area consists of Braunton Burrows, which is a unique sand dune system habitat of hundreds of flowering plants designated as both a Special Area of Conservation and a Site of Special Scientific Interest. Management of this area focuses on ensuring the protection and enhancement of the sand dunes and its adjacent coastal habitat, which includes a coral reef with a diversity of coral and marine life seen nowhere else in the UK and the Taw and Torridge estuary, which is an important feeding ground for long distance migratory birds.

CASE STUDY

The North Devon Biosphere Partnership is the body responsible for coordinating the management of the reserve in line with the vision and objectives of an agreed strategy for the years 2014–2024. The partnership works closely with willing local communities to manage the environment sustainably in ways that will conserve unique habitats, generate income, reduce poverty and improve the health and wellbeing of people.


19. Draw a labelled diagram to show three different ways in which soil erosion can be controlled and reduced by farmers. 20. Define what is meant by sustainable agriculture. 21. What does the biocontrol of pests and diseases mean? Describe an example of one kind of biocontrol used on sustainable farms. 22. In 2012, three researchers (Gaybullaev B, Chen and Gaybullaev D) published their results of fifty years of hydrological measurements of the volume of water in the Aral Sea. Date 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Water volume in cubic kilometres 1093 1007 925 786 664 502 327 239 149 112 98

Citation: Gaybullaev, B., Chen, S. & Gaybullaev, D. Appl Water Sci (2012) 2: 285. doi:10.1007/s13201-012-0048-z a) Draw a simple line graph, bar graph or histogram to show the changes which occurred between 1960 and 2010. b) By what proportion did the volume of water shrink in the Aral Sea between 1960 and 2010? c) Which five year period saw the greatest absolute decrease in the volume of water? d) Which five year period saw the single greatest proportionate loss of water?

246

END OF TOPIC QUESTIONS

e) Explain the main causes of the depletion of water in the Aral Sea over this time period.

Answers to these questions can be found at the back of the Teacher Guide.


4. Water and its management questions 1. Name four stores of surface water on Earth. 2. What important natural process does the water cycle describe? 3. On a copy of the summary diagram of the water cycle below, write in the following missing labels in their correct position: precipitation (used twice), vapour transport, transpiration by plants, percolation through rocks and groundwater flow condensation condensation .....................................

evaporation

.....................................

evaporation

.............................................

evaporation .....................................

surface run-off river ................................... ...................................

lake land

ocean

...................................................

4. In your own words, and using a diagram to help, explain how water is extracted from underground aquifers. 5. Explain why groundwater reserves in some part of the world are being depleted. Describe with an example some of the effects of groundwater depletion.

247

7. What does desalination involve? Why is desalination not more widely used around the world at present?

END OF TOPIC QUESTIONS

6. Las Vegas in Nevada in the United States is facing a water crisis. What has caused this crisis and what is the city trying to do to solve it?


4 Water and its management

4 Water and its management Introduction This section reinforces and extends student learning by: • •

Consolidating and developing the factual material in the Student Book that students will be required to recall and explain (AO1) Advancing student thinking through providing more challenging content and activities than those in the Student Book, which extend some areas of the specification and require the synthesis of information and the application of knowledge and understanding to unfamiliar contexts (AO2) Enabling students to grasp that the effective management of environmental issues requires a coherent and holistic approach to problem solving through the principles of sustainable development (AO3)

This is achieved through the provision of: •

• •

Extension content and related activities that secure and progress student knowledge and understanding through tasks that require handling information from a variety of sources to reach conclusions and make judgements Supplementary case studies that reinforce and advance key principles and concepts and support evaluative thinking A decision making or problem solving exercise that encourages students to appreciate the complexities of environmental management and the pivotal role of the principles of sustainable development in achieving successful outcomes

Links to other chapters Water is the world’s most important natural resource and the fundamental component of both biotic and abiotic elements of ecosystems upon which all life on Earth relies. Agriculture, for example, would not be possible without it. The constant movement of water through the closed system of the hydrological cycle has been a major determinant of atmospheric conditions and weather patterns anywhere in the world for billions of years. Pollution of this atmospheric water through human economic activities poses serious environmental management challenges, such as acid rain, in many regions of the world today. Ocean and other saline water accounts for almost all the water found on Earth. Maintaining the integrity of ocean ecosystems as a sustainable source of resources like fisheries and energy supplies, to meet the demands of a rapidly growing global population, presents another critical and immediate environmental issue. Pollution of oceans, particularly as a result of pumping or transporting oil, is an everpresent threat to fragile marine habitats and the biodiversity that lives within them. Human life depends on a tiny fraction of the world’s water that is held in freshwater reserves. These freshwater reserves are unevenly distributed, which creates water-rich and water-poor regions in which shortages occur. Millions of people lack access to both safe drinking water and improved sanitation facilities and are affected by water-borne diseases as a result.

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4 Water and its management

Water and its management topic

Links to other subject content

Section

Global distribution of water

Oceans as a resource

5

The water cycle

Increasing agricultural yields Flooding

3 6

Water supply

Increasing agricultural yields Soils for plant growth Drought

3 3 6

Water usage

Agricultural types

3

Water quality and availability

Human population distribution and density

8

Multipurpose dam projects

Energy resources and the generation of electricity

2

Water pollution and its sources

Earthquakes and volcanoes Atmospheric pollution – causes and impacts

6 7

Impact of water pollution

Impact of oil pollution

2

Managing pollution of fresh water

Management of oil pollution Tropical cyclones Managing atmospheric pollution

2 6 7

Managing water-related disease

Changes in population size

8



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4 Water and its management

Extension content and related activities Water quality and availability Latin America and the Caribbean, with water reserves of 13 867 billion cubic metres and available water reserves per person of 22 162 cubic metres, is the most water-rich region in the world. However, the one country that is the exception to this rule is Peru. All of Peru suffers from either physical or economic water shortage. The situation is worse along the narrow strip of land between the Andes Mountains and the Pacific Ocean. Here is where the Atacama Desert is found (the driest hot desert in the world), with an annual average rainfall of only 6 mm a year and home to 70 per cent of the country’s population (21 million). Eight million people live in the city of Lima alone, and this number increases by 100 000 a year. It is the second driest capital city in the world after Cairo in Egypt. Over one million residents in Lima do not have access to improved water supplies or sanitation facilities.                 Fig. 4.1 Peru.

Fig. 4.2 Districts of Peru.

Fig. 4.3 Annual precipitation in Peru.

 Fig. 4.4 In the Bellavista neighbourhood in Peru, water is often contaminated and unsafe for drinking.

 Fig. 4.5 Panoramic view of Lima.

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4 Water and its management

With only two per cent of Peru’s available water reserves, but eight out of ten of the country’s people, the city of Lima is facing major water supply problems. At the same time that the population of the city is growing rapidly, its main source of water is drying up. Currently the city gets most of its water from the Rio Rimac and two other rivers that flow out of glaciers high in the Andes Mountains. However these glaciers are melting rapidly. Estimates indicate that glaciers in the Peruvian Andes have lost a third of their surface area since 1970 as a result of global warming. Ironically, water supply will actually increase slightly in the next few years as more of the glaciers melt, but a massive decline is predicted after 2030.       



 Fig. 4.6 Average glacier thickness change.



Fig. 4.7 Global land-ocean temperature index. The grey line represents the annual mean, and the black line represents the 5 year mean.



Describe what has happened to the glacier whose data is shown in Figure 4.6 since the 1960s and suggest why it has happened using the information in Figure 4.7. Water shortages affect those in Lima without running water the most as they have to rely on expensive water deliveries by truck. One third of the city’s population live in shanty dwellings known as barriadas. People living in barriadas have to pay much more for water than anyone else in the city despite being the poorest residents.

 Fig. 4.8 A typical barricada in Lima, Peru.

 Fig. 4.9 A fog catcher in South America.

 Collins Cambridge IGCSE® Environmental Management Teacher Guide 

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4 Water and its management

Many of the inhabitants of the barriadas in Lima have become ‘fog catchers’ as they look to source drinking and irrigation water from water droplets in the atmosphere. Giant nets are used to create artificial condensation surfaces. The water droplets condense on the nets and then fall to the bottom to be collected for drinking or to be channelled away to crops. Now read the newspaper article at: http://www.theguardian.com/glo bal-development/2012/sep/ 19/peru-fog-catchers-watersupplies  Fig. 4.10 The diagram above shows how giant nets (known as ‘fog catchers’ or ‘fog collectors’) can be used to create artificial condensation surfaces. 

• • •

Make a list of all the ways the poorest communities of Lima benefit from collecting water by ‘fog catching’. What is the cost of a ‘fog catcher’ and where has the money required come from? In what ways do you think ‘fog catching’ could be a good example of sustainable development for the poorest people in Lima?

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4 Water and its management

Decision making exercises and reflection 1. Diarrhoea is the second leading killer of babies and young children in the world. The United Nations Children’s Emergency Fund (UNICEF) estimates that this water-borne disease accounted for 9 per cent of all deaths among children under the age of five worldwide in 2015. This equates to over 1400 young children dying each day or about 530 000 children in a year. Most deaths from diarrhoea occur among children less than two years old.





Fig. 4.26 Percentage of deaths among children under 5 years of age, attributable to diarrhoea, by country.

a) Describe the general distribution of countries in the world where diarrhoea accounts for 10 per cent or more of childhood deaths. ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... b) The most severe threat to life posed by diarrhoea is dehydration. Explain what dehydration is and why you think it presents such a threat to babies and young children. ...................................................................................................................................................... ...................................................................................................................................................... ..................................................................................................................................................... ...................................................................................................................................................... ......................................................................................................................................................

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4 Water and its management





Fig. 4.27 Percentage of population with improved sanitation by country.

c) The map in Figure 4.27 shows the proportion of the population using improved sanitation facilities. Explain what you understand by the term ‘improved sanitation’. ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... d) How does the information in Figure 4.27 help to explain the distribution of deaths as a result of diarrhoea in Figure 4.26 that you described earlier? ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... 2. The country of Cambodia in Southeast Asia has one of the highest incidences of diarrhoea amongst children of any country in the world. Diarrhoea accounts for 20 per cent of all deaths of children aged under five, which translates to 10 000 overall deaths each year.



 Fig. 4.28 Location of Cambodia.

Fig. 4.29 Cambodia.

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4 Water and its management

a) UNICEF is working with the government of Cambodia and other partners in the country to reduce childhood deaths caused by diarrohea. One important part of its work is educating children about the importance of handwashing using soap. Suggest why this simple and inexpensive change could reduce childhood deaths from diarrhoea in Cambodia by up to 40 per cent. ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... Another focus of UNICEF’s work in Cambodia is to provide every home with a toilet. The cost of doing this is a challenge in Cambodia, which is one of the poorest countries in Asia. Over two million people survive here on less than US$1.20 a day. 



Fig. 4.30 Pumping raw sewage out of a gutter on a city street in Phnom Penh, Cambodia.

b) Using examples of improved sanitation that you have studied in other countries of the world, describe what UNICEF could do in Cambodia that would be cheap and effective. ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ...................................................................................................................................................... ......................................................................................................................................................

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