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IMPACTS OF
GLOBAL
WARMING ON
IRRIGATION
ENGINEERING
CONTENT
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Introduction of Global Warming
Causes of Global Warming
Impacts of Global Warming
Droughts
Floods
Level Rising Temperatures of Oceans /sea
Tornadoes
Hurricanes
The Melting of Mountain Glaciers
The Reduction of Snow Cover
Coastal Erosion
INTRODUCTION
Global warming is the term used to describe a gradual
increase in the average temperature of the Earth's
atmosphere and its oceans, due to which permanently
change occurs in the Earth's climate.
CAUSES OF GLOBAL WARMING
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Most of the climate scientists are agree that the
main cause of the current global warming is due to the
"green house effect“
There may be other causes like
Respiration
Mining activities
Rapid industrialization
Increased in auto mobile use
GREEN HOUSE EFFECT
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present in the atmosphere absorbs infrared radiations reflected from the surface
of the earth and heats up the atmosphere.
SOURCES OF GREEN HOUSE GASES
Sunlight’s energy remains trapped in the atmosphere
FLOODS & DROUGHTS
CAUSED BY GLOBAL
WARMING
DROUGHTS CAUSED BY GLOBAL
WARMING
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A drought is an extended period of dry weather
caused by a lack of rain
Increased temperatures cause more evaporation
some places will receive greater concentrations of
rain and other places will receive less (droughts)
EFFECTS OF DROUGHTS TO
IRRIGATION
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Amount of water in lakes, rivers, and streams
Crop Losses
Drying of Irrigation Canals
Affect the coastal Areas
Cause Heat Waves
Affect LiveStock
HOW FLOOD IS CAUSED BY
GLOBAL WARMING
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A flood is an overflow of water that submerges
land which is usually dry
The rate of evaporation from the ocean seems to be
increasing
EFFECTS OF FLOOD TO
IRRIGATION
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Embankments of barrages and rivers
Damages underground piping system
Destroy agricultural crops
Affect the water table
Damage Head Canal
Affect whole Irrigation System
CASE STUDY OF 2010 FLOOD
DAMAGES OF 2010 FLOOD
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Affects the 79 Districts of Country
20 Million people affected
1600 Casualties
1.89 Million homes Destroyed
Huge Damages of Water Courses, Tube wells
Damage the crops of Approximately
1.32 Million Hectares
CROPS DAMAGES OF 2010 FLOOD
IRRIGATION DAMAGES OF 2010
FLOOD
MAP OF FLOOD AFFECTED AREAS
LEVEL RISING TEMPERATURES OF
OCEANS /SEA
CAUSED BY GLOBAL WARMING
RISING TEMPERATURE OF OCEANS
AND SEA
Rising temperature of ocean and sea may be more significant
than the direct effect of higher temperature.
Because….
• The world's agricultural output is heavily dependent on
irrigation.
• Out of a global cropped area of 1500 million ha, 16% is
irrigated.
• Global warming is likely to have a major impact on the
hydrological cycle and consequently on irrigated agriculture.
RISING TEMPERATURE OF OCEANS
AND SEA
As we have discussed that atmospheric temp raises due to
green house effects so it raises the temp of sea/ocean on the
following two mechanism
Two major mechanisms are causing sea level to rise.
First, shrinking land ice, such as mountain glaciers and polar
ice sheets, is releasing water into the oceans.
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Second, as ocean temperatures rise, the warmer water
expands. Trapped within a basin bounded by the continents,
the water has nowhere to go but up. :
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RISING TEMPERATURE OF OCEANS
AND SEA
The consequences of sea level rises due to temp include
 Threats to coastal communities
 Some 40% of the world’s population lives within 62
miles of the ocean.
RISING TEMPERATURE OF OCEANS
AND SEA
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Saltwater intrusion
Sea-level rise can mean that saltwater intrudes into
groundwater drinking supplies, contaminates irrigation
supplies, or overruns agriculture fields.
RISING TEMPERATURE OF OCEANS
AND SEA
TORNADOES AND HURRICANES
CAUSED BY GLOBAL
WARMING
TORNADOES AND HURRICANES
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Tornadoes:
A tornado is rapidly spinning air that develops from a
thunderstorms and is on the ground.
The ingredients for a tornado are a thunderstorm, winds
changing speeds with height and rapidly rising air.
Hurricanes:
A hurricane is a huge organized thunderstorm
complex that develops over the ocean
The ingredients are warm ocean water, weak upper
level winds, and low pressure
TORNADOES AND HURRICANES
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Comparison between Tornadoes and Hurricanes:
HOW DO TORNADOES FORM?
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The formation of tornadoes can be described into 3
steps:
Air Rotates Because of Wind Shear
Faster Spin Makes a Funnel Cloud
The Funnel Rotates and Touches Down
HOW DO HURRICANES FORM?
IMPACTS OF TORNADOES & HURRICANES
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Irrigation Systems:
Damaging winds caused extensive
damage to numerous pivot style irrigation
systems that farmers use to water crops
Flooding:
Heavy rains and ocean waters brought
ashore by strong winds can cause
flooding in excess of 50 cm (20 in)
over a 24 hour period.
IMPACTS OF TORNADOES & HURRICANES
Storm Surge:
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An abnormal increase in the ocean's
level, sometimes in excess of several
meters high.
Impacts to Agriculture
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As hurricane winds, rainfall, and storm
surge cause direct and indirect effects
on the environment, this can also impact
agriculture.
MELTING OF GLACIERS
CAUSED BY GLOBAL
WARMING
MELTING OF GLACIERS
MELTING OF GLACIERS
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Over a Thousand years ago, Asians used to irrigate
their lands by the melted water from glaciers.
During Warm season, snow melts slowly, releasing a
steady flow of water.
Over the last few decades, Glaciers are melting at
a torrid pace as an adverse effect of Global
warming & climate change.
MELTING OF GLACIERS
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Effects of Glacier Melting:
 Reduced
water for agricultural use
 Shrinkage of river based irrigated land
 Contamination of coastal groundwater supply
 More floods & droughts
 Mudslides, dam break etc.
MELTING OF GLACIERS
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Acc. to WWF, Himalayan Glaciers are retreating
10-15 m/year, causing rivers to be changed into
seasonal streams.
This glacier melting would pose freshwater scarcity
needed for the crop production, thus leading to
food shortage.
The world food security is threatened by the glacier
melting more in Himalayas and Tibet plateau.
MELTING OF GLACIERS
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Acc. to IPCC reports, Himalayan glaciers could melt
entirely by 2035.
This melting of glaciers could soon deprive the
major rivers of India, China & Pakistan.
In the Indus, Ganga, Yellow, and Yangtze River
basins, where irrigated agriculture depends heavily
on rivers, the glacier melt will shrink harvests and
could create unmanageable food shortages.
MELTING OF GLACIERS
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The Yangtze River in China, is threatened by the
disappearance of glaciers which will effect 369m
people who rely heavily on rice from fields irrigated
with its water.
In the Ganga river alone, the loss of glacier melt water
would reduce river flows by two third, causing water
shortage for 500m people and 37 per cent of India’s
irrigated land.
Similarly, 60% of Pakistan’s people, depend on grain
irrigated by the Indus river, which is also dependent on
meltwater from Himalayan glaciers, are under threat of
food & water scarcity.
COSTAL EROSION AND ITS IMPACTS
ON IRRIGATION
CAUSED BY GLOBAL WARMING
COSTAL EROSION AND ITS
IMPACTS ON IRRIGATION
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Erosion: erosion is the action of surface
processes such as water flow or wind
that remove soil, rock or dissolved
material from one location on
the Earth's crust then transport it away
to another location.
Natural rates of erosion are controlled
by the action of geomorphic drivers.
COASTAL EROSION
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Coastal erosion, which
occurs on both exposed and
sheltered coasts, primarily
occurs through the action of
currents and waves but sea
level tidal change can also
play a role.
Cont:
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Hydraulic action takes place when air in a joint is suddenly
compressed by a wave closing the entrance of the joint. This
then cracks it.
Wave pounding is when the shear energy of the wave hitting
the cliff or rock breaks pieces off.
Cont:
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Coastal erosion can pose a
risk to residential
developments, roads,
lifeline utilities and coastal
structures and adversely
affect the irrigation water
and agricultural land.
IMPACTS OF COASTAL EROSION
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Danger to life in the case of sudden onset landslide events
Structural damage or destruction of buildings and
infrastructure
Damage or destruction of lifeline infrastructure such as
water, sewage and gas pipes and roads
Loss of land, resulting in coastal cliffs or shorelines
retreating closer to other buildings
Land instability at neighboring slopes and properties
Loss of beach amenity due to cliff collapse or sea wall
construction.
IMPACTS ON IRRIGATION
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Increased salinity.
Enhanced waterlogging.
Reduction of irrigation water.
Increased Sedimentation.
Shrinkage of agricultural land.
Shortage of Food.
THANK YOU
EACH OF US MUST TAKE STEPS TO PROTECT OUR EARTH FROM GLOBAL WARMING