2.10
Uses of Rivers
2.10.1
Hydro-electric Power (HEP)
Dams
are often builds across
rivers to tap on the river
energy to generate
hydroelectric power.
Hydroelectric power plants
convert the kinetic energy
contained in falling water
into electricity. Hydropower
is currently the world's
largest renewable source of
electricity, accounting for
6% of worldwide energy
supply or about 15% of the
world's electricity. In
Canada, hydroelectric power
is abundant and supplies 60%
of our electrical needs.
Hydroelectric
power plants capture the
energy released by water
falling through a vertical
distance, and transform this
energy into useful
electricity. In general,
falling water is channeled
through a turbine, which
converts the water's energy
into mechanical power. The
rotation of the water
turbines is transferred to a
generator, which produces
electricity. The amount of
electricity, which can be
generated at a hydroelectric
plant, is dependent upon two
factors. These factors are:
-
the
vertical distance
through which the water
falls, called the
"head",
and
-
the
flow rate, measured as
volume per unit time.
2.10.2
Irrigation
Irrigation
has been practiced
throughout the world. There
are modern ways to obtain
water from the river as well
as traditional ways.
Irrigation is very important
to areas where there is long
period of drought, areas
with seasonal rainfall.
Irrigation has helped
farmers to have double or
even up to triple cropping
per year.
2.10.3
Fertile Alluvial Soil
Floodplain
and delta are good
agricultural land, which
have fertile alluvial soil.
The alluvial is increased
when the river floods. The
flat and low-lying
floodplain and delta makes
it easier for people to
build settlement and farm.
Many urban settlements start
in the fertile floodplain.
Bangkok in the Menam Chao
Phraya Delta of Thailand is
one good example.
