In dry parts of Asia and Africa where
the rain was sparse and the surface
water inadequate, man has had to
search for-other sources of water namely
ground water. Through this need
he learned to tap ground water and
extract it to the surface. Thus qanats
were developed in Persia.Techniques
of qanat construction were later
introduced by persians to parts of
Asia and dry lands of Africa.Construction
of qanats which can be considered
one of the world's few wonders(miraculous
works of ancient man)and certainly
has been the most beneficial
of all to mankind was continued up to
recent decades by simple, however geneous,
methods and measuring devices
and with the use of hand tools. Some
qanats have served generation after
generation, days and nights.
Techniques of Qanat construction
reveal that Persians had a good knowledge
of the occurrence and movement
of ground water millenniums earlier.
Through qanats they could bring ,by gravity,
groundwater from hillside aquifers
to playa skirts and establish cities
and centers of an ancient civilization.
In recent decades, due to the growth
in population,expanded uses of water
and changes in cropping(which resulted
from improvement of living standards
due to higher incomes)qanat waters alone
could not satisfy demands. Thus,farmers
and small landowners had to turn
to the use of deep wells. Extended pumping
from these wells,lowered water table
and decreased flow of many qanats
and carelessness in their up-keep left
many dry. Difficulties of qanat construction
and disputes in qanat ownership
have been amongst the major problems
resulting in abondoning qanats.
Unless these problems are overcome,
the qanats will continue to dry.
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