HUMAN INTERACTION WITH THE ENVIRONMENTMª EUGENIA ALBA TORREIRO

Biology and Geology 3º ESO A

WATER IS A FUNDAMENTAL RESOURCE

Use of water

Domestic and urban

Bathroom, preparation of food, watering the garden.

Washing, drinking, etc.

Comsumption

Farming Industry

Water for livestock, cleaning, irrigation, etc.

Refrigeration, cleaning of materials, etc

OTHER USES

Without comsumption

Obtaining energy

Means of transport

Recreation Landscapes resources

River transport, transporting crude oil, etc

Hydroelectrical-energy

Swimming, sailing, fishing, water sports, etc.

Rowing boat

Conservation of species and natural spaces, etc.

WATER MANAGEMENT Xestión da auga

Fresh water is essential for human survival.

Fresh water represents just 3% of all the water of the planet: it is an extremely scarce resource.

It is very important to manage its use carefully by means of:

Hydrological plants. These allow us to optimise water resources.

Dams for storing water.

Desalination plants for extracting salt

Plants for extracting groundwater.

However these plants can have a negative effect on the environment and lead to the risk of overexploitation.

WATER MANAGEMENT Saving water

Agriculture uses the most amount of water, so it is very important to improve irrigation.

It is also important to reduce consumption in the home.

Agriculture: water’s biggest consumer

WATER MANAGEMENT Sewage treatment plants

Sewage contains a great deal of polluting material. It is important to treat and clean it in water treatment plants, before returning it to the environment..

Fresh water

1. Physical treatment 2. Biological treatment

3. Chemical treatment

4. Sludge treatmentSludge is treated to obtain biogas or for agricultural use.

Sand, fats.

Salts and heavy metals are eliminatedMicrorganisms descompose organic

compounds.

WATER MANAGEMENT Making water potable

A number of purification treatments are needed to obtain drinking water or “potable water” which is water of sufficiently quality that it can be consumed safely.

GLOBAL ENVIRONMENT PROBLEMSThe overexploitation of resources

The overexploitation of resources produces:

The deforestation of large areas and the progressive loss of soil due to erosion.

The extinction of species (loss of biodiversity).

The exhaustion of geological resources and the contamination and destruction of landscapes as a result of the extraction of these resources.

Southern Mexico

Deforestation

The extinction of species

Exhaustion of oil

Oil well in the Gulf of Mexico

AIR POLLUTION Greenhouse effect

Natural greenhouse effect

The greenhouse effect is a natural phenomenon, thanks to which the Earth retains part of the solar radiation and reaches a temperature that makes life on the planet possible. Pollution, together with the progressive lost of forests, leads to greater retention of this radiation, leading to an increase in the temperature of the planet, in other words global warming.

1. Solar radiation hits the Earth’s surface.

2. The Earth reflects part of this solar radiation.

3. Part of the radiation reflected by the Earth is returned to space.

4. Another part of the radiation is absorbed or retained by the atmosphere due to the action of certain gases, such as CO2 and H2O vapour.

INCREASE IN NATURAL GREEHOUSE EFFECT

1. Solar radiation hits the Earth’s surface.

2. The Earth reflects part of this solar radiation.

3. Part of the radiation reflected by the Earth is returned to space.

4. Pollution, together with the progressive disappearance of forests, causes greater retention of the radiation, which leads to an increase in the temperature of the planet

How the increase in the greenhouse effect occurs:

CO2

CO2

Increase in natural greenhouse effect

THE HOLE IN THE OZONE LAYER

The ozone layer filters the ultraviolet rays of the solar radiation (which can cause skin cancers) and prevents the majority of them from reaching the Earth’s surface.

The CFCs used in aerosols and refrigeration systems destroy this layer, causing the so-called hole in the ozone layer.

ACID RAINAcid rain is rain or snow with higher acidity than normal.

Acid rain is generate in several phases:1) Industry, thermal power plants and

vehicles emit polluting gases into the atmosphere (nitrogen and sulphur oxides) generated by the combustion of fossil fuels.

2) These oxides react with water in the atmosphere and turn into nitric and sulphuric acid, which return to the Earth in the form of rain or snow with a high level of acidity.

3) The acid rain destroys the leaves of the trees an acidifies the soil, causing the death of forests and the destruction of lakes. In the cities, it contributes to stone sickness, which destroys limestone or marble monuments.

SOME EFFECTS CAUSED BY ACID RAIN

Stone sickness which destroys limestone and marble monuments

Death of forests and acidification of the soil.