Impact of Climate Change on Water Resources

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WEL COME
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Presentation on
IMPACT OF CLIMATE CHANGE IN RELATION TO WATER
Course No. PP- 605
Presented By TARU ANIL SAHEBRAO Ph.D. Fruit
Science. Reg. No-12/61

• Submitted to,
• Dr. R. S. Wagh
• Associate Professor,
• Department of Agril. Botany,
• PGI, MPKV, Rahuri

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Climate Change
United Nations Framework Convention on Climate
Change (UNFCCC) defines climate change as a
change of climate which is attributed directly or
indirectly to human activities that alters the
composition of the global atmosphere and which is
in addition to natural climate variability
observed over comparable time periods General
Definition Any systematic change in the
long-term statistics of climate elements (such as
temperature, pressure, or winds) sustained over
several decades or longer.
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Drivers of change
River flows groundwater quality
Population demand for water
Wealth equity access
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Impacts of Climate Change in Relation to Water

• Air and Water Temperature Increases
• Changing Rainfall Patterns
• Droughts
• Groundwater
• Glacier Melt
• Sea level rise
• Agriculture and food security
• Water Security
• Health

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Air and Water Temperature Increases

• Temperatures are changing in the lower
  atmospherefrom the Earths surface all the way
  through the stratosphere (EPA 2007b). Most
  climate change scenarios project that greenhouse
  gas concentrations will increase through 2100
  with a continued increase in average global
  temperatures (IPCC 2007a, as found in EPA 2007c).
  
• The average surface temperature of the Earth is
  likely to increase by (1.1 to 6.4C) by the end
  of the 21st century, relative to 1980-1990, with
  a best estimate of (1.8 to 4.0C).
• The average rate of warming over each inhabited
  continent is very likely to be at least twice as
  large as that experienced during the 20th century
  (IPCC 2007a).

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Changing Rainfall Patterns

• A decline in monsoon rainfall since the 1950s has
  already been observed.
• The frequency of heavy rainfall events has also
  increased.
• A 2C rise in the worlds average temperatures
  will make Indias summer monsoon highly
  unpredictable.
• At 4C warming, an extremely wet monsoon that
  currently has a chance of occurring only once in
  100 years is projected to occur every 10 years by
  the end of the century.

Fig. Rainfall During the year 2007-2011
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Droughts

• Evidence indicates that parts of South Asia have
  become drier since the 1970s with an increase in
  the number of droughts.
• Droughts have major consequences, in 1987 and
  2002-2003, droughts affected more than half of
  Indias crop area and lead to a huge fall in crop
  production.
• Droughts are expected to be more frequent in some
  areas, especially in north-western India,
  Jharkhand, Orissa and Chhattisgarh. Crop yields
  are expected to fall significantly because of
  extreme heat by the 2040s.
• Investments in RD for the development of
  drought-resistant crops can help reduce some of
  the negative impacts.

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Groundwater

• More than 60 of Indias agriculture is rain-fed,
  making the country highly dependent on
  groundwater.
• Even without climate change, 15 of Indias
  groundwater resources are overexploited.
• Although it is difficult to predict future ground
  water levels, falling water tables can be
  expected to reduce further on account of
  increasing demand for water from a growing
  population, more affluent life styles, as well as
  from the services sector and industry.

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Glacier Melt

• Glaciers in the northwestern Himalayas and in the
  Karakoram range - where westerly winter winds are
  the major source of moisture - have remained
  stable or even advanced.
• On the other hand, most Himalayan glaciers -
  where a substantial part of the moisture is
  supplied by the summer monsoon - have been
  retreating over the past century.
• At 2.5C warming, melting glaciers and the loss
  of snow cover over the Himalayas are expected to
  threaten the stability and reliability of
  northern Indias primarily glacier-fed rivers,
  particularly the Indus and the Brahmaputra. The
  Gangas will be less dependent on melt water due
  to high annual rainfall downstream during the
  monsoon season.

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Sea level rise

• Mumbai has the worlds largest population exposed
  to coastal flooding, with large parts of the city
  built on reclaimed land, below the high-tide
  mark. Rapid and unplanned urbanization further
  increases the risks of sea water intrusion.
• With India close to the equator, the
  sub-continent would see much higher rises in sea
  levels than higher latitudes.
• Sea-level rise and storm surges would lead to
  saltwater intrusion in the coastal areas,
  impacting agriculture, degrading groundwater
  quality, contaminating drinking water, and
  possibly causing a rise in diarrhea cases and
  cholera outbreaks, as the cholera bacterium
  survives longer in saline water.

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Agriculture and food security

• Even without climate change, world food prices
  are expected to increase due to growing
  populations and rising incomes, as well as a
  greater demand for biofuels.
• Rice While overall rice yields have increased,
  rising temperatures with lower rainfall at the
  end of the growing season have caused a
  significant loss in Indias rice production.
  Without climate change, average rice yields could
  have been almost 6 higher.
• Wheat Recent studies shows that wheat yields
  peaked in India and Bangladesh around 2001 and
  have not increased since despite increasing
  fertilizer applications. Observations show that
  extremely high temperatures in northern India -
  above 34C - have had a substantial negative
  effect on wheat yields, and rising temperatures
  can only aggravate the situation.

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Continue.

• Seasonal water scarcity, rising temperatures, and
  intrusion of sea water would threaten crop
  yields, jeopardizing the countrys food security.
• Should current trends persist, substantial yield
  reductions in both rice and wheat can be expected
  in the near and medium term. Under 2C warming by
  the 2050s, the country may need to import more
  than twice the amount of food-grain than would be
  required without climate change.
• Crop diversification, more efficient water use,
  and improved soil management practices, together
  with the development of drought-resistant crops
  can help reduce some of the negative impacts.

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Water Security

• Many parts of India are already experiencing
  water stress. Even without climate change,
  satisfying future demand for water will be a
  major challenge. Urbanization, population growth,
  economic development, and increasing demand for
  water from agriculture and industry are likely to
  aggravate the situation further.

• An increase in variability of monsoon rainfall is
  expected to increase water shortages in some
  areas. Studies have found that the threat to
  water security is very high over central India,
  along the mountain ranges of the Western Ghats,
  and in Indias northeastern states.

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Health

• Climate change is expected to have major health
  impacts in India- increasing malnutrition and
  related health disorders such as child stunting -
  with the poor likely to be affected most
  severely. Child stunting is projected to increase
  by 35 by 2050 compared to a scenario without
  climate change.
• Malaria and other vector-borne diseases, along
  with and diarrheal infections which are a major
  cause of child mortality, are likely to spread
  into areas where colder temperatures had
  previously limited transmission.
• Heat waves are likely to result in a very
  substantial rise in mortality and death, and
  injuries from extreme weather events are likely
  to increase.
• 5 million people mainly children die every
  year from preventable, water-related disease is
  surely one of the great tragedies of our time.
• over 34 million people might perish in the next
  20 years from water-related disease

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Review Articles
Water resources and climate change An Indian
perspective In recent times, several studies
around the globe show that climatic change is
likely to impact significantly upon freshwater
resources availability. In India, demand for
water has already increased manifold over the
years due to urbanization, agriculture expansion,
increasing population, rapid industrialization
and economic development. At present, changes in
cropping pattern and land-use pattern,
over-exploitation of water storage and changes in
irrigation and drainage are modifying the
hydrological cycle in many climate regions and
river basins of India. An assessment of the
availability of water resources in the context of
future national requirements and expected impacts
of climate change and its variability is critical
for relevant national and regional long-term
development strategies and sustainable
development. Sustainable development of surface
water and groundwater resources within the
constraints imposed by climate change and future
research needs in India. (Mall-2006)
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What can be done

• The development of indicators of climate change
  impacts on freshwater, and operational systems to
  monitor them
• Impact studies of climate change at the monthly
  or higher temporal resolution scale is desirable
  rather than only on annual scale
• The efficient use of ground water resources will
  need to be incentivized.
• Develop local scale data sets and simple
  climate-linked computerized watershed models.
• Adaptation processes and methods which can be
  usefully implemented in the absence of accurate
  projections, such as improved water-use
  efficiency and water-demand management, offer
  no-regrets options to cope with climate change.

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Continue.

• An integrated approach is needed, given the
  diversity of interests to arrive at sustainable
  solutions.
• RD studies are needed for the identified thrust
  areas under National Water Mission to achieve the
  envisaged objectives and goals.
• Improvements in irrigation systems, water
  harvesting techniques, and more-efficient
  agricultural water management can offset some of
  these risks.

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THANK YOU