A comprehensive presentation of subchapter 3.4 The Human Impact, from the third chapter of Physical Geography, AS Cambridge, Rocks and Weathering.

1. ASGEOGRAPHYREVISION
ROCKSANDWEATHERING
3.4 THEHUMANIMPACT

2. KEYTERMSANDDEFINITIONS
Acid precipitation is any precipitation with a pH lower than 5.0.
Contaminants are materials that have harmful impacts and degrade
the environment.
Dry deposition refers to materials transported in suspension in the air
that settle on the ground as dry matter.
Hazardous wastes are wastes that pose a present or potential threat to
humans or wildlife.
Incineration is the burning of refuse, often in a specially designed
facility.
Opencast mining is a form of extensive excavation in which the
overlying material (overburden) is removed by machinery, revealing the
seams or deposits below. In the USA it is referred to as strip mining.

4. KEYTERMSANDDEFINITIONS
Pollutants are materials that have harmful impacts and degrade the
environment. Pollution refers to materials that have harmful impacts
on the natural environment, or the act of releasing such materials.
Recycling is the process of taking apart an old product and using the
material it contains to make a new product.
Spoil heaps are large unconsolidated mounds of waste materials
extracted in the process of obtaining an ore.
Subsidence is the collapse of the ground downwards. Tailings are the
impurities left behind after a mineral has been extracted from its ore.
Waste is the residual materials and by-products that are generated by
human use of the Earth’s resources and end up unwanted and unused.
Wet deposition refers to materials transported in suspension in the air
that eventually fall to the ground as precipitation.

5. TOPICSUMMARY
Landforms can be created by human activities (tipping, excavation and
hydrological interference and by farming).
Man-made changes in landforms can be deliberate or unintentional.
Man’s ability to affect the natural environment has increased as
technology has developed.
Weathering processes can be intensified by changes in local climate as
shown by increased chemical weathering in urban areas.
Human activity has many impacts on the nature and rate of limestone
denudation.
Rates of mass movements can be altered by building or excavation,
drainage or agriculture.

6. TOPICSUMMARY
Most of the changes to slopes caused by human activities have been
very minor in relation to the scale of the natural land surface. Slope
modification tends to increase as a construction moves on to steeper
slopes.
Excavation and dumping involve the mining of sediments, the tipping
of waste material and the subsidence they create.
The environmental destruction caused by strip mining, for example,
far exceeds any other direct form of impact that humans have on
landforms.
Pollution is defined as the contamination of the Earth / atmosphere
system to such an extent that normal environmental processes are
adversely affected. Pollution can be natural, such as from volcanic
eruptions, as well as human in origin.

8. TOPICSUMMARY
Derelict land is land that has been so damaged by industrial or other
development that it is incapable of beneficial use without treatment. The
most common toxic soil pollutants include metallic elements and
compounds, organic chemicals, oils and tars, pesticides, explosive and toxic
gases, radioactive materials and asbestos.
The environmental impacts of mining are diverse. Habitat destruction is
widespread, especially if opencast or strip mining is used.
The mining of coal has a number of environmental impacts.
Acidification is caused by the release of sulphur dioxide (SO2) and nitrogen
oxides (NOx) from industrial complexes, vehicles and urban areas.
Acidification affects water quality, growth of vegetation, weathering of
buildings and even human health.
Acid waters can be neutralised by adding lime. Coal with a low sulphur
content could also be used.

12. ADDITIONALWORK
1. With the use of examples, outline the ways in which human beings
can create new landforms.
2. Describe and explain the environmental impacts of mining.
3. Explain a the causes, b the consequences and c the potential
solutions to the problems of acid rain.
4. Examine ways in which human impact has accelerated natural
processes. Use examples to support your answer.

13. SUGGESTEDWEBSITES
www.defra.gov.uk/environment/quality/land/contaminated presents the
UK government’s DEFRA information on contaminated land.
www.sciencealert.com.au/opinions/20102605-21004.html provides
information on abandoned mine management in Australia.
http://cockpitcountry.blogspot.com/ gives views against bauxite mining in
Cockpit Country.
www.ohvec.org/galleries/mountaintop_removal/007/ shows some
stunning and depressing photos of mountaintop removal.
http://environment.nationalgeographic.com/globalwarming/acid-rain-
overview is National Geographic’s overview on acid rain.
www.epa.gov/acidrain/# is the USA’s Environmental Protection Agency’s
site on acid rain.