IGCSE Environmental Management Chapter 3 Hydrosphere Notes

(1)

Chapter 3: Hydrosphere

Ighelp.blogspot.com BlackandWhiteandWise.blogspot.com

Environmental Management

By Niharika Shinde

(2)

Composition of the Air

Gas

Percentage

Composition (%)

Nitrogen

78 Oxygen

21 Carbon Dioxide

0.04 Argon

0.96

(3)

Energy Source

• _{Sunlight is a shortwave radiation}

(4)

Insolation

• Insolation is the amount of solar radiation reaching a given area. • Insolation rate is the highest at the equator and is lowest at the

(5)

Atmospheric Pollution – Causes

• Fossil fuels in power stations

• Waste from industries

• Bare soil: is carried by wind resulting in soil erosion

• _{CFCs and Halons}

• _{Deforestation}

(6)

Atmospheric Pollution – Effects

• _{Poor air quality, can affect lungs:}

• _Asthama

• _{Reduced visibility}

• Acid rain

–

Due to sulfur dioxide and oxides of nitrogen

–

Source: Vehicles, power stations, industries

–

Effects: Crop destruction, forest destruction, soil

erosions, trees become less resistant to droughts,

leaves fall early, acidity in lake causes death of marine

animals

(7)

Atmospheric Pollution – Effects

• _{Ozone layer Depletion}

–

Cause: CFCs

–

Source of CFCs: Hair sprays, refrigerants, air conditioning

–

Increased UV radiation

–

Increased UV radiation

» Skin cancer

» Effects humans and animals

–

Less transpiration

» Less precipitation due to less cloud formation

» Droughts, decrease in crop yields and food supply

(8)

Green house gases:

Carbon dioxide – Source: burning fossil fuels and wood & deforestation Methane – Source: Deforestation and decomposition of waste

(9)

Increased Greenhouse effect

• _{Effect of this increased process:}

–

Increase in global temperature

–

Ice sheets melting

–

Rise in sea levels

–

Rise in sea levels

–

Flooding in low-lying coastal areas

–

Defenses breached

(10)

Atmospheric Pollution – Solution

• _{Catalytic convertors installed in vehicle}

exhausts

• Using gas instead of petrol and diesel

• Adding powdered limestone in lakes

• _{Limestone treatment in chimneys of power}

stations to convert Sulfur Dioxide into Calcium

Sulfate before it leaves the chimney the oxides

of nitrogen are reduced by using ammonia

(11)

Atmospheric Pollution – Solution

• _{Natural gas power stations instead of coal}

power stations

• Alternative energy sources like Hydro-electric

power stations

• _{Reduction in use of CFCs}

• _{Increased plantation}

(12)

Measuring the weather

• _{Air pressure:}

–

Barometer (either mercury or aneroid)

• _{Mercury barometer: mercury level increases and falls}

with increase and decrease in air pressure

• _{Aneroid: upper surface is sensitive to changes in}

pressure

(13)

Measuring the weather

• _Temperature:

–

Thermometer

(either minimum or maximum)

• Maximum thermometer consists of mercury and a

metal index. The mercury rises and falls with changes in

temperature, pushing and leaving behind the metal

index in the process.

• Minimum thermometer consists of alcohol and metal

index. Alcohol expands and contracts with changes in

temperature, moving the metal index up and down

(14)

Measuring the weather

• _{Precipitation:}

–

Rain gauge

• Rain enters the funnel and the measuring cylinder is used to take readings.

• Wind:

–

Weathervane

–

Anemometer

• 3 or 4 cups that rotate and there is a counter.

• _Sunshine:

–

_{Sunshine Recorder}

• Glass sphere and recording paper with divisions for the time of day

(15)

Farming systems

• Arable

– Only crops are grown

• Pastoral

– Rear animals either for animal by-products or for meat

• Commercial

– Crops and animals are produced to sell – Crops and animals are produced to sell

• _Subsistence

– Crops and animals are produced to feed the farmers’ own family

• Extensive

– Small yield, large farmland area

• Instensive

(16)

Farming

• _{Normal cultivation (rainforest)}

1. Small plot is cleared by slash and burn method

2. Crops planted

3. No nutrient added to soil

4. Soil loses fertility over the years

5. Plot is abandoned and another plot is cleared

and used

(17)

Farming

• _{Wet rice cultivation (Asia)}

–

Monsoon brings heavy rains

–

Flat flood plains and delta

–

Silt soils – fertile, deep, easy to work with

–

Silt soils – fertile, deep, easy to work with

Techniques to Increase Yield - Farming

• Irrigation from rivers and lakes through canals • Inorganic Fertilizers and Pesticides

• Tractors

(18)

Adverse effects of modern practices

• _{Overuse of fertilizers & pesticides leads to}

eutrophication and nitrates accumulate in

drinking water

• Eutrophication: excessive richness of nutrients in a lake or other body of water, frequently due to run-off from the land, other body of water, frequently due to run-off from the land, which causes a dense growth of plant life.

• _{Irrigation causes salinization}

• Salinization: the process of increasing the salt content in the soil is known as salinization

• _{Overcultivation and overgrazing results in soil}

erosion and desertification

(19)

Solutions

• _{Instead of irrigation surface channels, use}

sprinklers and trickle drip

• Use organic fertilizers

• Mixing crops

(20)

Climatic Hazards

• Tropical cyclones :

– storms formed when sea water is at its hottest, air above sea surface heats up and warm moist air starts to rise (show diagram), low

pressure develops deeply in the centre and sucks up more air from the surface, huge circular swirl of cloud forms, around which wind speed increases, rainfall from clouds.

• Impact: • Impact:

– Immediate loss of life – Destroy buildings

– Flooding due to rains – Economic losses

– Infrastructure damaged

– Disruption of water supplied – diseases – Farming economy ruined