The Impact Of Hurricanes On The Physical and Human Environment
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A tropical cyclone is a low-pressure system that forms in the tropics.
Hurricane is the name given to fully developed tropical cyclones that
are found in the Atlantic Ocean, Caribbean Sea, Gulf of Mexico and the
North Pacific Ocean east of the International Date Line.
When local residents of an area refer to a hurricane, they are
speaking of the violent, stormy weather system that brings torrential
rains and destructive, high velocity winds of over 74 miles per hour.
Hurricanes are also characterised by a heavy cloud cover, which
reduces sunshine and makes visibility and temperatures very low. In
other parts of the world, tropical cyclones are given other names. For
example, in Australia they are known as Willy Willies, in India there
are known as Tropical Cyclones and in the Pacific they are known as
Hurricanes can only form in tropical regions due to their need for
certain atmospheric and weather conditions only found there. Most
hurricanes originate on the west coast of Africa, in the form of
thunderstorms. As these thunderstorms move westwards over the ocean,
they become low-pressure systems; first in the form of tropical
depressions, then tropical storm and then finally hurricanes.
Hurricanes usually take a matter of days to develop from a depression
to a hurricane, but this time period can vary. For hurricane formation
to take place, warm waters of temperatures higher than 27 degrees
Celsius must be present. From these warm waters, evaporation takes
place at a high rate. Warm, moist air above the ocean surfaces rises
via convection currents. As this air rises it condenses and storm
clouds form. During condensation, energy is released in the form of
heat, known as latent heat of condensation. Latent heat of
condensation powers a hurricane. This latent heat warms air and causes
it to rise. The risen air is replaced by more warm moist air from the
ocean surfaces. This process is repeated continuously in a cycle. As
heat is transferred from the surface to the atmosphere continually, a
circular wind pattern (counter-clockwise in the N. Hemisphere) is
formed. Converging winds and pressure gradient also help in hurricane
formation as they cause warm, moist air to rise, causing low pressure
and circular wind patterns also.
A hurricane is made up of three main parts: the eye, the eye wall and
the rain bands. The eye is the calm region found to the centre of the
hurricane. Here, pressure is at its lowest (sometimes 960 millibars).
Conditions at the eye are dry and not very windy. The eye wall
surrounds the eye and is made of thick cumulonimbus cloud. Here, winds
are most intense and rainfall heaviest. The rain bands are made of
many thunderstorms circulating out from the eye. These play a roll in
the evaporation/ condensation cycle, which provides the system with
Figure 1: Structure Of A Hurricane
Hurricanes are perhaps the most devastating natural disaster affecting
the Earth today. They have a major impact of the physical and human
The physical environment can be defined as the structural features of
the land, air and sea. The passing of a hurricane is always
destructive to this environment. Most of the destruction is caused by
the high-velocity winds and torrential rainfall that occur.
These high-velocity winds along with low pressure lead to the
formation of storm surges (tidal waves). Tidal waves, sometimes many
metres tall, crash against coastal areas; eroding beaches and damaging
coastal homes and buildings. Tidal waves also cause major damage to
boats anchored in harbours.
Figure 2: A Tidal Wave
Figure 3: Barne’s Bay Eroded after Hurricane Luis
Strong gusts of winds easily uproot trees, bushes and other vegetation
types. The pressure of the wind against the trees is so many Newtons
per squared metre that the trees have no choice but to go down. Since
many animals live in trees and bushes. Many habitats are destroyed.
The damage to vegetation also affects the carbon dioxide to oxygen
ratio in the atmosphere and also accelerates soil erosion, as fewer
roots are present in the soil.
Powerful, destructive winds also push down communication poles,
causing communication and utility lines to snap. Hurricane winds are
also agents of pollution. They strip materials off buildings, vehicles
etc. and deposit them at sea, on the coast and other sites.
The torrential rains (and sometimes tidal waves) are responsible for
the flooding that occurs during hurricanes. Flooding is a natural
disaster in itself. Houses and vehicles are swept away during a flood,
possessions are destroyed and water supplies are polluted.
Figure 4: Flooding after Hurricane hits Haiti
Heavy torrential rainfalls on a heavy unstable mountainside/ hillside
can cause the occurrence of mudslides and landslides. If these occur
buildings and crops are destroyed.
Together, torrential rains and powerful winds, batter homes and other
buildings, sometimes completely destroying them. They also bring on
the death of crops and livestock, usually by uprooting and drowning
respectively. The rains and wind can often damage road and bridges and
Figure 5: Houses Destroyed By Severe Winds.
The human environment is the people that inhabit the Earth.
Hurricanes impact on the human environment in a largely negative way.
Due to the destruction of homes, many people are left exposed during
hurricanes. Many of these people often die and survivors are usually
very ill with pneumonia. Death tolls tend to be high and can range
from under a hundred to hundreds of thousands.
Repair and restoration of damaged buildings and reconstruction of
destroyed buildings can cost a country millions to billions of
dollars. This greatly affects the economy and financial situation of a
country. It also affects the lives of the citizens as the rebuilding
process can take many years.
Polluted and contaminated water supplies cannot be used. If they are
diseases and infection can be contracted and spread.
Damaged roads and workplaces make everyday functions had to carry out.
Trade and exchange are disrupted and life is made uncomfortable.
The breakage of communication and utility lines is a major
inconvenince to a people. They have to find means of living without
electricity, telephone and sometimes television.
The destruction of crops and livestock has a profound effect on the
human environment. These provide food sources for people. When
hurricanes occur, fields of crops can be lost and many animals can
die. When this occurs there are food shortages and hunger and
starvation increases, causing an increase in crime.
In conclusion, hurricanes have a negative impact on both the human and
physical environment. They are natural disasters, which cannot be
prevented or stopped from occurring. Due to technological advancements
made in the last few decades though, hurricane formation can be
spotted very early and their progress tracked and predicted. Hurricane
warnings are then issued to places possibly and definitely in danger.
Warnings give people time to reinforce their homes by boarding up etc,
to stock up on food supplies and to move to “safer locations” if
necessary and possible.
Nonetheless, you can never guarantee your safety in the world’s
greatest natural disaster, the hurricane.