Geomorphic
system
By
Marjorie Henry, Contributor
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| Tarrant
High's Jerome Campbell blocks
Kingston College's Tahj Fisher
during action in the ISSA/KFC
High School basketball competition
at St. George's College. KC won
75-16. - Ian Allen Photo |
In
the last lesson, I shared some general
information on groundwater, another
one of the topics from the geomorphic
system in the geography syllabus.
The
information was on the origin of groundwater.
May I hasten to say that although
it is not stated as one of the specific
objectives in the syllabus, knowledge
of this can prove useful in understanding
the topic as well as offering a good
response to questions. The question
for discussion comes from the June
1998 examination paper. It is as follows:
(a)
Draw a labelled diagram to show the
structure of an artesian basin.
(3 marks)
(b)
Name ONE country in the Caribbean
where underground water is the major
source of water supply. (1 mark)
(c)
Describe TWO ways in which underground
water can be useful to persons in
the Caribbean. (6 marks)
(d)
Explain THREE ways by which underground
water can be polluted. (9 marks)
(e)
Explain the relationship between rainfall
and underground water within the hydrological
cycle. (5 marks)
Total
24 marks
(a)
The diagrams below show the structural
nature of artesian basins. The upper
diagram shows a synclinal basin while
the lower one shows how inclined strata
coming up against impermeable rock
may produce the same artesian condition.
Source: Morphology And Landscape
- Harry Robinson.
(b)
Countries in the Caribbean where underground
water is the major source of water
supply include Barbados; Antigua;
New Providence in the Bahamas and
some of the islands of the Netherlands
Antilles. (NB: These areas have low
rainfall and experience a fairly dry
climate. The relative importance of
underground water supplies tends to
be greatest in these areas.)
(c)
Ways in which underground water can
be useful to persons in the Caribbean
include supplying water for:
(i)
Domestic purposes;
(ii)
Agricultural purposes:
(iii)
Industrial purposes.
The
underground water sources are mainly
tapped by sinking wells. The points
are only listed here but a full answer
requires that you expand on these.
(d)
Ways in which underground water can
be polluted are as follows:
(i)
Untreated domestic sewage is allowed
to soak down into the ground resulting
in water supplies becoming contaminated.
(ii)
Industrial waste materials find their
way into underground water supplies,
thus contaminating them. The source
of industrial pollution can be from
the alumina factories and sugar factories.
(iii)
Chemicals used in agricultural activities
can also seep into the underground
water so causing it to become contaminated.
Additional
information on this can be obtained
from the text New Caribbean Geography
by Vohn A. M. Rahil.
(e)
The relationship between rainfall
and underground water within the hydrological
cycle. The whole process of the circulation
of water between the land, sea and
atmosphere is known as the hydrological
cycle. In the atmosphere, water vapour
condenses into clouds, which precipitate
rain or snow, returning water to the
land. A considerable proportion of
the water received from rain or snow
percolates downwards into the soil
and rocks, filling up joints and pore-spaces
and forming what is known as groundwater.
It re-enters the hydrological cycle
by way of springs.
*
Marjorie Henry is Geography teacher
at Glenmuir High School in Clarendon.
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