Water resources
Global Overview
While 67% of Earth’s surface is covered by
water, only less than 2.7% of global water
is freshwater. Most of the freshwater
(2.05%) are locked in ice caps and glaciers.
Only less than 0.7% is available for human
use.
Over two thirds of the
earth's surface is covered
with water, 97.2% of which
is contained in the five
oceans. The Antarctic ice
sheet, containing 90% of all
fresh water on the planet, is
visible at the bottom.
Atmospheric water vapour
can be seen as clouds,
contributing to the earth's
albedo.
Iceberg and Polar cap store most of the fresh water
on Earth
Volume of water stored in
the water cycle's reservoirs
Reservoir Volume of water Percent
(106 km³) of total
Ocean 1370 97.25
Ice caps & glaciers 29 2.05
Groundwater 9.5 0.68
Lakes 0.125 0.01
Soil Moisture 0.065 0.005
Atmosphere 0.013 0.001
Streams & rivers 0.0017 0.0001
Biosphere 0.0006 0.00004
Scarcity of fresh water
On a global basis, fresh water is a
increasingly scarce resource. It is partially
caused by increasing population coupled by
change of consumption pattern and climate
changes.
Water consumption for food
production (I)
Meat production use a lot of water when
compared to growing food crops.
A shift in food consumption pattern toward
more meat consumption will cause a
substantial increase in water consumption.
Water consumption for food
production (II)
Competing water uses (I)
Competing water uses (II)
Industrialized / developed countries tend to
use more water in their industrial
production.
Other countries tend to use more water for
agricultural uses.
Fresh Water supply
Problems related to Water crisis
Inadequate access to safe drinking water by
over 1.1 billion people
Groundwater overdrafting leading to
diminished agricultural yields
Overuse and pollution of water resources
harming biodiversity
Regional conflicts over scarce water
resources sometimes resulting in warfare.
Threats to fresh water resources
Climate change causes change in
frequencies of droughts and floods.
Depletion of aquifers caused by over-
consumption as a result of population
growth.
Pollution and contamination by sewage,
agricultural and industrial runoff.
Distribution of population and
water resources
Pressure of freshwater ecosystem
Fresh Water Outlook
Estimated from existing data, some
countries are going to experience serious
shortage of fresh water supply in the
coming 20 years time.
China, India and South Africa and Middle
East countries may among the most
adversely affected countries.
Desalination of sea water as
fresh water supply
Desalination of sea water can be done either
via distillation or membrane process.
Both process requires large amount of
energy and thus costly, which means
desalination remains an expensive option
for providing reliable fresh water supply,
restricted to only economically well-off
countries.
“The wars of the next century will be about
water" World Bank vice-president Ismail
Serageldin(quoted in New York Times, 10
August 1995).
“Fierce competition for fresh water may
well become a source of conflict and wars
in the future.”
Kofi Annan, March 2001
WATER- A MAJOR CONCERN
● Only about one percent of the world’s total freshwater supply is
readily available for consumption by humans, animals and for
irrigation.
● Water security is emerging as an increasingly important
● Population growth continues to surge, the demand for water is
increasing substantially, without a concomitant increase in water
resources
● In South Asia, conflict over freshwater has strained relations
between India and Bangladesh, as well as India and Pakistan.
INDUS RIVER
BASIN
CAUVERY RIVER
THE POTENTIAL CAUSES
Contending Water Uses
Contending Water Uses:
■ Water is a common pool resource
■ Contention between different kinds of uses
■ The issue is one of rapidly decreasing water supply amidst a
growing number of users who require larger quantities with every
passing year
■ Case of Keoladeo National Park,
■ Case of Vadali village of Gujarat and
■ The Majuli island case.
THE POTENTIAL CAUSES
Contending Water Uses
Population Growth and
Demand
Population Growth and Demand
♦ Growing population and changing values have increased
pressure on existing water supplies
♦ Urban needs often conflict with agricultural needs, as well
as with increased demand for water for endangered species,
recreation, and scenic enjoyment
♦ Conflict in the Bhavani
♦ The Palkhed canal system of upper Godavari project
THE POTENTIAL CAUSES
Contending Water Uses:
Population Growth and
Demand
Pollution
Pollution
Almost 70% of its surface water resources
A growing number of its groundwater reserves are
already contaminated by biological, toxic organic and
inorganic pollutants
Unsafe for human consumption as well as for other
activities such as irrigation and industrial needs.
♦ Kolleru wildlife sanctuary
♦ The case of khari river
THE POTENTIAL CAUSES
Contending Water Uses:
Population Growth and
Demand
Pollution
Micro level dispute
MICRO LEVEL DISPUTE
Conflicts on a truly micro scale – within a village, a community or
around a small tank
Monitoring failure at Kanpur
Shapin River Basin in Jharkhand
THE POTENTIAL CAUSES
Contending Water Uses:
Population Growth and
Demand
Pollution
Micro level dispute
Dams and Displacement
THE POTENTIAL CAUSES
Contending Water Uses:
Population Growth and
Demand
Pollution
Micro level dispute
Dams and Displacement
Transboundary dispute
TRANSBOUNDARY DISPUTE
Disputes over shared water resources have a long history
Inter-state and inter-country dispute
Access to water has been a source of dispute and contention
– Baglihar hydropower project (BHP)
– Sutlej Yamuna Link Canal
THE POTENTIAL CAUSES
Contending Water Uses:
Population Growth and
Demand
Pollution
Micro level dispute
Dams and Displacement
Transboundary dispute
Privatisation
PRIVATISATION
Inviting private sector participation in dam and
reservoir projects
Opposition to the idea of `privatisation of water'
Privatisation poses a threat to that commitment
because once privatised, water will no longer be
provided on the basis of need but on the ability to pay
DAMS AND DISPLACEMENT
India is the third largest dam builder country in the world. It now has
over 3600 large dams and over 700 more under
construction.
The displacement caused by large scale irrigation and
hydro-projects
Displacement and resettlement of people is the least
concern of large dam builders
Sardar Sarovar Dam
Haripad Project In Madhya Pradesh
Tehri Dam
Displacing populations
Estimate: 40-80M displaced by dams.
(10M reported in China; 1.5M for Three Gorges)
Usually poor/indigenous people who leave behind
productive farms and ancestral homes. They
rarely receive benefits of the project.
Results in conflicts, social problems, cultural loss,
economic disaster
Although people starting building dams thousands of years ago, technology for large dams didn’t evolve until the 19th century
Today….
60% of the world’s rivers are dammed
There are ~ 45,000 large dams (>15m high) and over 1500 under construction
There are ~ 800,000 smaller dams
Volume: 10,000 km3 (5x vol of all river water)
Have Dams Achieved their purpose?
Dams have saved countless millions of lives from
floods
30%-40% of 271 million hectares of irrigated lands
worldwide rely on dams
Dams contribute water to 12-16% of the world’s
food production
India has been self-sufficient in food production
since 1974 due to irrigation from reservoirs
Have Dams Achieved their purpose?
Hydropower provides 19% of world’s electric supply
(low greenhouse gas emissions)
– 13% in US (92,000 MW= 500 barrels oil or 150 coal plants;
prevents 200 million tons of CO2;
85-90% efficient compared to 50% for gas turbines)
– 99% in Norway
– 75% in New Zealand
– 70% in Latin America
But there are serious objections to dams and
problems to overcome
Large populations need to be resettled
Economic benefits are often not achieved
Dams harm the environment
Water is lost through evaporation and seepage
Dams fill with sediment and change the
geomorphology of the river
Dams have a life that ends… then what?
Dams can be unsafe; have killed thousands
Environmental Issues
Dams change the chemical, physical and bilogical
processes of river ecosystems. They alter free-
flowing systems by reducing river levels and
downstream ecosystems, blocking the flow of
nutrients, changing water temperature and oxygen
levels, and impeding or preventing fish and
wildlife migration.
Environmental effects of dams
Cuts off water from floodplains and wetlands that are habitats to
fish, birds and other species.
Cuts off migration of fish, even with fish ladders
Interrupt natural high-low flow patterns that many species need for
normal reproduction cycles
Cuts off sediment flow to d.s. habitats; clear water further scours
in-place sediments
Reduces fresh water supplies to estuaries and costal areas, often
destroying fish industries
Promotes reproduction of mosquitos and other disease-producing
organisms.
Environmental effects of dams
Reservoirs trap nutrient-ladened sediments which accelerates cycle
of eutrophication (O2 depletion); lower layers of water often lack
DO.
Methane production due to decaying biomass is high in tropical
reservoirs; this greenhouse gas is worse than CO2 and counters the
greenhouse gas savings of hydropower.
Releases from lower levels of reservoir alter temperature and DO
levels of river (affect water’s ability capacity to process waste)
Construction of dams and associated transmission lines and roads
often destroy pristine wilderness
Negative influences of the dam
- ecological problems
- social and cultural problems
- financial problems
DEVASTATING FLOODS IN ASSAM
STATE, INDIA
June 28, 2012
The Brahmaputra River
overflowed during monsoon
rains over the past week,
flooding more than 2,000
villages and destroying homes
in the northeast of the country
FLOOD: ASSAM STATE;
JUNE 28, 2012
WILD BUFFALO GOING TO HIGHER
GROUND; JUNE 28
HOMELESS BULUT VILLAGE
FAMILY: JUNE 30
What is drought?
One definition:
A deficiency of precipitation over an
extended period that causes water
shortage for some group or activity.
Elements of the definition:
– deficiency of precipitation
– extended period (how long is "extended"?)
– water shortage for some user ("group or activity")
Drought depends on the user
Crops rely on stored soil water. Soil water can be rapidly
depleted, so that monthly droughts may affect crops.
