Subtopics include: 1. Submergence of forest land 2. Devastation of forests 3. Prone to floods, droughts & landslides 4. Loss of soil fertility 5. Loss of Biodiversity 6. Loss of Species 7. Effects on tribal people 8. Displacement of tribal people

1. Dams and their Effects on Forests and
Tribal People
Subtopics Include:
1. Submergence of forest land
2. Devastation of forests
3. Prone to floods, droughts &
landslides
4. Loss of soil fertility
5. Loss of Biodiversity
6. Loss of Species
7. Effects on tribal people
8. Displacement of tribal people
+
Case Study
(Narmada Bachao Andolan)
Submitted By:
• Aditya Vashistha (001)
• Akshet Patial (002)
• Archit Gupta (005)
• Siddharth Raj (019)
ECE (EVE)
Submitted To:
Dr. Ritika Chauhan Mam

2. Introduction
 The damming of rivers produces
dramatic and far-reaching
environmental changes:
 of the first order are hydrological
changes, including water quality
 the second order affects channel
morphology and aquatic, riparian, and
floodplain vegetation.
 the third order includes forests and
tribal people.
 Thus there are important linkages
between the physical, chemical, and
biological components of river, land
and forests systems that are
disordered when a river is impounded

3. Submergence of Forest Land
 The CWC has stated that, according to a study of 116 projects (details not
available), the average forest submergence per project was 2,400 ha. Even if
we take this to be the correct figure, the total submergence between 1980 and
2000 would have been 4,504,800 ha. (roughly four and a half million hectares).
 Data was available on forest submergence for 60 dams. Based on these,
the average forest area submerged per dam works out to approximately
4,879 ha. Therefore, the 1,877 dams built between 1980 and 2000 would
have submerged 9,157,883 ha. (roughly 9.1 million ha.) of forests.

4. Devastation Of Forest
 Many hydropower projects grab sections of land that are used to grow rice, as forest
areas, and as residential areas. From a social perspective, scientists claim that this
causes local people to lose their livelihoods and forces them to change their
traditional practices and culture. In an economic respect, because of losing traditional
livelihoods, local people have to earn wages and follow market-driver crops. The last
point to examine here is the impact of hydropower on environmental factors.
 Many ethnic minority groups have been living for long time. They live around forests
and their livelihoods rely heavily on forest resources, including the collection of non-
timber forest products and traditional shifting cultivation practices for both cultural and
economic purposes.
 In such areas, local people’s food, medicine, and water come from the forest. A loss
of forests means a loss of their livelihoods.

5.  By curtailing the rainy season flow, the
dam inhibits the ability of the ecosystem
to regenerate itself.
Prone to floods, droughts and landslides
 Heavy monsoon flow acts as a flush for
the riverbed and river mouth, clearing
them of accumulated silt, garbage and
stale water.
 The absence of such a flow creates
significant problems downstream and
decreases the capacity of the riverbed
to accommodate peak flows, leading to
larger floods in the case of cloudbursts
or sudden releases of water.
 The areas where deforestation occurs
becomes prone to floods, droughts and
landslides

6. Loss of Soil Fertility
 It affects the land under cultivation , in
the catchment area as the crops get
submerged under water.
 The soil becomes less fertile due to
decrease in decomposition of dead
leaves in that particular area.
 Dams hold back the sediment load
normally found in a river flow, depriving
the downstream of this. The
downstream water erodes its channels
and banks. This lowering of the
riverbed threatens vegetation and river
wildlife. A major example of soil erosion
problems is the Aswan Dam or Aswan

7. The Effect Of Dams On Biodiversity
 Dams alter the ecosystems and
biodiversity of rivers.
 In the old industrialized countries,
development now is towards the
decommissioning of dams rather
than the construction of new ones,
but in many developing countries
exploitation of rivers is proceeding
at a fast rate
 Downstream effects
 Downstream of dams the habitats along the
rivers are altered because the sediment
and organic material that is normally
carried along by the flowing water is held
back by the dam and sinks to the bottom or
is spread on the banks of the reservoir.
 Species that are associated with rapids,
waterfalls or the humid microclimate that
arises in their vicinity diminish in numbers
or completely disappear

8. Loss Of Species
 There are a number of different
migratory patterns of river-
dwelling species. These include
the well-known anadromous
fishes e.g. salmon and hilsa and
the catadromous fishes such as
eels
 Brazil, several species of
migrating catfish have been
drastically reduced in abundance
as a result of dams; catches in
the downstream fisheries have
been reduced by 70%
 Reservoirs trap suspended particles, reducing turbidity downstream. Many
species are adapted to natural turbidity. For example turbid water catfishes have
small eyes, refined senses of smell and touch in their sensitive barbels. The
turbid water helps conceal the fish and other biota from visual predators like
birds.

9. Effects On Tribes And Locals
 However, the dams’ effects have
included much more than forest loss
and the major environmental changes
have impacted on local people, at both
the dam site and in the entire river
basin.
 Not only are the best agricultural soils
flooded by the reservoir, but major
changes occur in the environment,
where the river’s flora and fauna begins
to disappear, with strong impacts on
 For many years large hydroelectric
dams have been portrayed as
synonymous with development.
 Another reason can be that most users
of hydro-electricity live far away from the
impacted areas and that the sites
selected for dam building have been
often those inhabited by indigenous
peoples, tribal people, ethnic minorities
and poor communities having little
capacity of being heard by the wider
national community

10. Violation Of Human Rights
Narmada Bachao Andolan
 Narmada Bachao Andolan is the most powerful
mass movement, started in 1985, against the
construction of huge dam on the Narmada River.
 Supports a large variety of people with
distinguished culture and tradition ranging from
the indigenous (tribal) people inhabited in the
jungles here to the large number of rural
population.
 The proposed Sardar Sarovar Dam and
Narmada Sagar will displace more than 250,000
people. The big fight is over the resettlement or
the rehabilitation of these people.
 There are plans to build over 3000 big and small
dams along the river.
 In far too many cases, dam-building has resulted in widespread human rights
violations. As most of us would, local peoples have persistently resisted the
destruction of their homelands and their forced “resettlement.” As a result, they
have had to face different types of repression, ranging from physical and legal
threats to mass murders.

11.  A majority of Tribal end up with less
income than before, less work
opportunities, inferior houses, less
access to the resources of the
common people such as fuel wood
and fodder, poor nutrition and poor
physical and mental health.
 The government should devise a
strategy to minimize tribal displacement.
 It must ensure 100 per cent
rehabilitation and make sure that the
fruits of development are shared with
the dispersed people as well.
 It must augment the rehabilitation of the
displaced persons of previous projects,
protect the customary rights of the tribal
people over natural resources and take
their opinions into consideration for
future projects.
What Can We Do ?

12. Bibliography / Sources
 Environmental Studies by Rajesh Dhankar
 http://appscgroup.blogspot.in/2013/09/damsand-their-effects-appsc-material-for-
mains-download.html
 http://www.cifor.org/forestsasia/hydropower-deforestation-unexpected-linkage-
obvious-one/
 https://www.internationalrivers.org/resources/environmental-impacts-of-large-dams-
african-examples-2029
 https://www.researchgate.net/publication/265914243_The_effect_of_dams_on_biodiv
ersity
 https://www.researchgate.net/publication/255643683_Biodiversity_Impacts_of_Large
_Dams
 https://theconstructor.org/structures/environmental-impacts-of-dams/236/
 http://www.ecoindia.com/education/narmada-bachao-andolan.html
 http://www.yourarticlelibrary.com/essay/dams-and-their-effects-on-forests-and-tribal-
people/28202