Unit 1 Dynamic Planet
Topic 4 Water World
Instructions
Complete this revision sheet using your exercise book and text book.
Store this revision sheet in your revision folder once it has been checked by your teacher.
Fill in the sheet in as much detail as possible to help you when you revise for your GCSE exams. If you would like
to achieve an A* this sheet needs to be completed to that level.
Write neatly so that is easy to read when you revise.
There is a completed copy of this sheet in the ilab if you would like to check your work. Ask at the counter for
the geography revision folder, it is only available for reference work in the library– not to take home.
2. Define the following words.
Evaporation = the changing of a liquid
into a vapour or gas.
Condensation= as water vapour cools it
turns back to a liquid
Precipitation= all the different forms of
water E.G rain, snow and sleet
Infiltration= when water is moving down
through soil
1.Put the following words into the correct column
below.
Evaporation Condensation Precipitation Runoff
Oceans Groundwater Lakes Rivers
Stores
Lakes
Groundwater
Oceans
Transfers
Rivers
Runoff
Processes
Evaporation
Condensation
Precipitation
Transpiration= evaporation from plants
Evapotranspiration = it is a combination of
evaporation and transpiration
Surface run-off= when the soil is full of
water and it cant take any more and the
rain runs over the surface
Percolation =_ it is when water goes
through rocks
3. Draw a diagram to show how the hydrological cycle links the biosphere, atmosphere and lithosphere
Atmosphere= .
Key
= Hyrdrosphere
= Atmosphere
= Biosphere
= lithosphere
The layerof gases above the
earths surface
Biosphere = the very
thin layer of living
things
Geosphere = the
rocks of the earths
crust and deeper in to
the earth towards the
core
6. River Rhine named example of the consequences of human activities on
Water supply
Source = Alps mountain range, Switzerland
Mouth = North sea at Rotterdam, Holland
Countries it flows through =France Germany Netherlands
Number of major cities on the Rhine =9
Length = 1320km long
7. List 7 uses of the River Rhine. The River Rhine is intensively used by people.
1.Provides water for 20 mill people = domestic use
2. Agricultural use = Provides water for irrigation of crops
3.Industrinl use = Water is sued for cooling in factories and to dispose of industrial waste
4.Hydroelectric power = To generate renewable electricity.
5. Waste disposal = Acts as a drain for sewage for a population of 55 million.
8. How is the River Rhine polluted and what are the consequences?
1.Agriculture= A major problem with the use of fertilisers occurs when they are
washed off the land by rainwater into rivers and lakes. The increase of nitrate or
phosphate in the water encourages the growth of algae. The algae form a
bloom over the water surface. This prevents sunlight reaching other water
plants, which then die. Bacteria break down the dead plants and as they respire these bacteria use up the oxygen in the water causing most other living
organisms to die.
2. Industrial = Industrial waste is in the river Rhine . When a fire in a chemical
factory was put out chemicals were washed into the river killing a ??? Stretch of
the river Rhine. Half a million fish were killed and some species became extinct.
There are 9 industrial cities on the banks of the Rhine. The risk of pollution is high.
Industry uses water for cooling and returns it to the river at a higher temperature. This is called thermal pollution.
3. Sewage Disposal= 55 million people live in the drainage basin of the Rhine.
Sewage is disposed of in the river. Bacteria consume the sewage. This uses up
oxygen reducing the amount of oxygen available for fish and other species.
4. The Effects of Climate Change on the Hydrological Cycle, people and ecosystems.
A. The impact on the Hydrological Cycle
1. The impacts on precipitation are difficult to predict (total amount and rainfall reliability)
- Warmer temperatures are likely to lead to more precipitation falling as rain instead of
snow
-There is more water vapour in the atmosphere then there should be an increase in precipitation
-Rainfall will be more intense—more rain will fall in a shorter period.
2. The impacts on evaporation
-As the atmosphere get warmer the evaporation rates increase
-Leading to more moisture in the air
- Warmer temperatures will increase evaporation from the soil making drought more
likely
3. The impacts on groundwater levels
-Increase of evaporation means less water stored in the soil and rock
5. The impact of insufficient and unreliable water supply on humans
Drought in the Sahel
A. Location = A narrow belt of land south of the equator ,Africa
B. Precipitation/ Rainfall
(i) When it falls = 1 a month
(ii) Total rainfall = 250—450mm a year
Describe what has happened since 1970= Lower rainfall. 25% below average in some
places. Rainfall is more intense (heavier)
Several long droughts.
Problems caused by torrential rain = Rainfall is so heavy it cannot infiltrate. Surface runoff is high. Flooding happens.
Problems caused by drought = Seasonal rivers and water holes dry up. The water table
drops making it harder to access ground water. Nomads cant feed animals because
vegetation cant grow. Subsistence farmers cant grow maize and millet. Grasses die,
and overgrazing by animals causes soil erosion and desertification. Food shortages and
famine occurs.
Many of the countries in the Sahel are developing countries such as Chad, Niger and
Sudan that have growing populations, drought puts pressure on food supplies. These
semi-arid lands are extremely fragile and water stress causes
regular famines and humanitarian crisis.
7. Disruption of water supply. Below are 3 examples of how people disrupt water supply.
A. Disrupting the water supply by deforestation.
Example = Amazon Tropical Rain Forest Brazil, South America.
(i) Impact on evapotranspiration = Removing trees reduces evapotranspiration, so less water
is recycled. This can lead to a reduction in rainfall and the possibility of desertification.
(ii) impact on the soil =
A. The soil is exposed to intense heat, which hardens the ground– making it impermeable
and increasing runoff.
B. It leads to loss of soil nutrients (because of a loss of biomass) Nutrients are quickly flushed
out of the system.
C. Raindrop splash washes out finer particles of soil, leaving behind coarser, heavier sand
surface.
(iii) Impact on Rivers=
It cuts out the process of interception. If trees are removed from watershed areas, this can
increase siltation of rivers and lead to increased flood risk.
B. Impact of overabstraction on water supply
Example = Thames Valley, Southern England, Europe
Reasons for overabstraction
Increasing demand for housing/growing population. Groundwater supplies have increasingly been used. The water table has dropped causing river levels to drop.
Impact of overabstraction on:(i) Rivers River levels have dropped effecting aquatic ecosystems– home to many plants
and animals. Some rivers have dried up completely.
(ii) Ecosystems River levels have dropped/dried up effecting habitats for plants and animals.
(iii) The water table/Aquifers The water table has dropped. The amount of water naturally
stored in aquifers has reduced.
C. Impact of dam and reservoir construction
Example = Katse Dam Lesotho, Southern Africa
Impact on:(i) River Levels downstream of the dam = Have dropped effecting ecosystems and water
availability for people.
(ii) Ecosystems/Species = Some species were endangered/made extinct by changing river
levels. e.g. A species of minnow.
(iii) Evaporation = From the reservoir increased.
(iv) Water supply downstream of Dams = Decreased as water was stored upstream in the
reservoir. This effected farmland and domestic water supply downstream.
.
8. Large scale water management schemes.
A. LEDC
Name of Dam = Katse
Developing country
Lesotho
Aims :
1. To provide water to sell to South Africa to
increase economic development.
2. To generate hydro electric power.
Costs :A. People living close to the dam
Land has been flooded when the reservoir was created. Local people have
lost their gardens/farm Land. They are no longer self sufficient in food and need
to be given food parcels (compensation) by the government.
The reservoir has also flooded roads effecting transport. School children now
have to walk significantly further to school.
Some people were made homeless.
2000 people were effected in total.
River ecosystems have been effected downstream as water levels are lower.
Benefits :
A. The population of Lesotho
Selling water to South Africa provides 75% of Lesotho's income.
This can be invested in the countries economic development e.g.. Schooling,
better health car and infrastructure (e.g. roads)
B. People living close to the dam
A wide range of jobs has been create from construction work to engineering.
C. South Africa
Township residents now have clean water supply to there homes. This helps improve hygiene and sanitation. It is safer and less time consuming than collecting water from shared stand pipes.
B. MEDC
Name of Dam: Colorado River, Hoover Dam , Reservoir = Lake Mead
Developed country
USA
Aims: 1. Water supply for 8 Million people living in Nevada, California and Arizona (including Las Vegas). This is an arid area that depends on water for farming, homes and recreation.
Costs :
1. Nearly all of the Colorados water is now used. Virtually none of it
reaches the sea.
2. The estuary (near the mouth) of the river is dead and because seasonal flooding no longer occurs bird and fish species numbers have declined.
3. Lake mead is running out of water, a demand increases, but
drought reduces inputs. In 2010, lake Mead was only 40% full and it could fall
below useable levels as early as 2020.
Benefits: 1. Water is supplied to 3 states/8 million people.
2. Lake Mead is used for recreation and leisure.
9. A small–scale intermediate technology ( sustainable) solution . Sand Dams
Name of NGO
Excellent development
Country Kenya
How sand dams work:
A Sand Dam is a steel reinforced concrete (or technically speaking, rubble stone
masonry) wall built across a seasonal sandy riverbed. During the rainy season, a
seasonal river forms and carries soil (made up of sand and silt) downstream. The
heavy sand accumulates behind the dam, whilst the lighter silt washes downstream over the dam wall. Within one to four rainy seasons the dam completely fills
with sand. However, up to 40% of the volume held behind the dam is actually water stored between the sand particles. The water can be abstracted from the sand
dam in three main ways: Traditional scoop holes; an infiltration gallery either leading a tank behind the dam and/or piped through the dam leading to a tap; an infiltration gallery leading to a sealed shallow well in the valley side – topped with a
hand pump.
How they are sustainable. Socially =
Each dam can store up to 120 litres of water. Water us stored under ground so it is protected from pollution. Clean water
helps improve sanitation, prevent disease. Decrease infant mortality. Improve
quality of life. Girls are no longer required to spend up to 8 hours a day collecting
water. They are bottom led community development schemes.
Environmentally= It helps provide a reliable water supply throughout the year in
Arid environments. Unlike big dams the impacts are only local. There are no negative environmental impacts.
Economically=
The cost of sand dams are vey low. Local materials are used to
build dams. Labour is provided free by the local community. No fuel is required.
There are no maintenance costs. Excellent development provide volunteers free to
train the community.