A p r es e n t
ation
on
dams
Prepare
d by :
Khalid T
ariq
Kurdistan-Erbil
10
e
lin
t
conclusion
ou
Design andco
ns
tru
Types of dam c tio
Purpose of th n
ed
Introduction am
Introduction
What is dam?
A dam is a barrier that stops or restricts the flow of water or
underground streams.
The use of reservoirs created by dams
Suppress floods provide water for activities such as
Irrigation Human
consumption
c t w ater
t o colle be
u se d c a n
a l s o be
e r w hich o n s.
Industrial
c a n w at o c ati
A dam storage of between l use
or for istributed
e n l y d
ev
Aquaculture Navigability
floodgates levees
Structures such as or (also known as dikes) are used to manage or prevent
water flow into specific land regions.
The purpose of dams
Water storage for
Flood irrigation, industrial,
control and human
consumption
T UR E
T RUC
BY S
TYPES OF DAMS
BY MATERIAL
BY SIZE
BY STRUCTURE
Arch dams Gravity
dams
Embankment dams
Arch-gravity
dams Barrages
An arch dam is a concrete dam that's curved upstream in plan, The arch dam is designed so that the force of the water against it,
known as hydrostatic pressure, presses against the arch, compressing and strengthening the structure as it pushes into its
foundation or abutments. An arch dam is most suitable for narrow gorges or canyons with steep walls of stable rock to support
the structure and stresses, Since they are thinner than any other dam type, they require much less construction material, making
them economical and practical in remote areas.
The Katse Dam, a 185m high concrete arch dam in Lesotho.
A gravity dam can be combined with an arch dam into an arch-gravity dam for areas with massive amounts of water flow but less
material available for a purely gravity dam. The inward compression of the dam by the water reduces the lateral (horizontal) force
acting on the dam. Thus, the gravitation force required by the dam is lessened, i.e. the dam does not need to be so massive. This
enables thinner dams and saves resources.
Hoover Dam
Embankment dams are made from compacted earth, and have two main types, ROCK-FILL and EARTH-FILL dams.
Embankment dams rely on their weight to hold back the force of water, like gravity dams made from concrete.
The Mica Dam in Canada.
A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by primarily
utilizing the weight of the material alone to resist the horizontal pressure of water pushing against it. Gravity dams
are designed so that each section of the dam is stable, independent of any other dam section.
Willow Creek Dam in Oregon, a roller-compacted concrete gravity dam
A barrage dam is a special kind of dam which consists of a line of large gates that can be opened or closed to control
the amount of water passing the dam. The gates are set between flanking piers which are responsible for supporting
the water load, and are often used to control and stabilize water flow for irrigation systems.
An example of this type of dam is the now-decommissioned Red
Bluff Diversion Dam on the Sacramento River near Red Bluff,
California.
BY MATERIAL
Steel Timber
dams dams
BY SIZE
International standards (including the International Commission on Large Dams, ICOLD) define large dams as higher than 15 m
(49 ft.) and major dams as over 150 m (490 ft.) in height. The Report of the World Commission on Dams also includes in the
large category, dams, such as barrages, which are between 5 and 15 m (16 and 49 ft) high with a reservoir capacity of more
than 3 million cubic meters (2,400 adrift).
Jinping-I Dam, China , 305-meter-tall ,arch dam.
DESIGN
General comments
AND CONSTRUCTION
– All dams are different.
– The consequences of dam failure may be disastrous.
– The force of water pressure is enormous.
– The level of acceptable leakage is low; usually it is in the range of liters per second, and often
totals less than the losses by reservoir evaporation.
– The foundation is a key part of the structure and needs careful exploration and improvement.
– The control of floods is an essential element in dam design and may also be a difficult problem
during construction on large rivers.
– The local seismic risk may modify the design.
– The impact of reservoirs on the environment demands special study.
CONCLUSION
Dams have been used to provide a store of water for agriculture, industrial uses, household
uses for thousands of years. Hydroelectric dams, additionally, act as an alternative to non-
renewable energy resources that constitutes the majority of the world’s energy. In the 20th
century, over $2 trillion was spent on making dams around the world. However, dams have
drastic damaging effects on the environment and on the populations that live near the dams
and so have become the subject of great scrutiny, with organizations concerned with
environmental health such as World Wildlife Fund (WWF) and International Rivers
advocating the removal of old dams and the use of Fund (WWF) and International Rivers
advocating the removal of old dams and the use of alternatives. In this article, Mission 2017
looks into the uses of dams and ways of maximizing their efficiency and minimizing their
environmental damage. The first part of the article looks into the details of dams and their
problems and the second part deals with possible solutions to the problems.
