1.1 Extreme hydrometerological and geohphysical events which impact
adversely on people, the economy and society. They invariably result in
death or injury, destruction of property and infrastructure and significant
economic and social disruption
1.2 Hydro-meteorological hazards include
Cyclones, Droughts and Floods
220.127.116.11 Any area of low atmospheric pressure that is created when air rises from the surface of the earth
18.104.22.168 Causes - As the air rises into the atmosphere, it is cooled and condensation occurs. This may
result in the formation of clouds and eventually precipitation, both of which re characteristics of
low pressure systems. Cyclones can also bring about windy conditions and are associated with
22.214.171.124 Effects - Destruction of Habitats
Destruction of crops/property
126.96.36.199 An extended period of lower than average
precipitation which causes water shortages.
188.8.131.52 Droughts can be localised - occurring in relatively small regions or can be much
larger - affecting entire continents
184.108.40.206 Causes - When surface water shortages are not recharged or replenished for a
number of consecutive seasons.
220.127.116.11 Effects - Restriction of non-essential water
Severe erosion results in desertification of an area, Dehydration, Disease, Death
18.104.22.168 An overflow of water that submerges on land which is very dry
22.214.171.124 Floods occur when areas of land that are usually dry become inundated. In most cases, floods occur
after a long period of prolonged rainfall. They can also occur in regions that have not experienced
rainfall, they may flood because of rainfall running downstream or meltwater, e.g. Bangladesh
126.96.36.199 Causes - Floods occur because the systems that are designed to cope with average levels of rainfall,
such as stormwater drains and levee banks, simply fain to work properly because of a blockage or
188.8.131.52 Effects - Loss of life, Damage to bridges, buildings, roads, homes
Can also result in loss of power, contamination of water
1.2.4 Hydro-meteorological hazards are natural
hazards caused by water, the weather, or a
combination of both
1.3 Geophyical hazards include
Earthquakes, Volcanoes, Landslides and
184.108.40.206 A series of vibrations on the surface of the Earth.
220.127.116.11 Earthquakes occur at plate boundaries
18.104.22.168 Causes - Earthquakes are caused by movements of rock within the Earth's
22.214.171.124 Tectonic plates float on the layer of semi-molten rock (mantle) that lies underneath them. Heat
generated by the Earth's core causes movements within the mantle, known as convection
currents. These currents make the tectonic plates move, collide, drift apart or slide past each
other which causes vibrations detected as earthquakes.
126.96.36.199 Effects - Falling rppfs, people being trapped in collapsed buildings, loss of
infrastructure and after shocks.
188.8.131.52 An opening within the Earth's crust, from which material (magma, volcanic gases, ash and dust)
from below the earth's surface is, of has been enjected
184.108.40.206 Volcanoes occur at plate boundaries, around the pacific ocean (rim
220.127.116.11 Causes - Heat from the earth's core heats up the surface of the volcano. The volcano
forms by material being forced upwards by the movement of tectonic plates
18.104.22.168 Effects - loss of crops, death, loss of houses, infertile land, volcanic ash
1.3.3 Landslides and Avalanches
22.214.171.124 The sliding of a large amount of rock or soil down a slope, under the force of gravity. An
'avalanche' usually refers to a sudden downward movement of snow or ice in a
126.96.36.199 Landslides can occur almost anywhere, they are also
188.8.131.52 Causes - possible triggers include heavy rainfall or earthquakes, Change to a slope that
causes an increase in its steepness (such as road cutting) and clearing of vegetation could
also trigger a landslide.
184.108.40.206 Effects - loss of land structure, destruction of houses, death.
1.3.4 Geophysical hazards are natural hazards
caused by the physical processes that
act upon, above or within the earth.