Global warming & Its Impacts

This presentation includes the introduction to global warming and its hazardous impacts on the earth. It covers the effects of global warming on irrigation engineering as well.

Best Regards:
Engr. Muhammad Ali Rehman

1. IMPACTS OF
GLOBAL
WARMING ON
IRRIGATION
ENGINEERING

2. CONTENT
Introduction of Global Warming
Causes of Global Warming
Impacts of Global Warming
Droughts
Floods
LevelRisingTemperaturesofOceans/sea
Tornadoes
Hurricanes
TheMeltingofMountainGlaciers
TheReductionofSnowCover
CoastalErosion

3. INTRODUCTION
Globalwarmingisthetermusedtodescribeagradual
increaseintheaveragetemperatureoftheEarth's
atmosphereanditsoceans,duetowhichpermanently
changeoccursintheEarth'sclimate.

4. CAUSES OF GLOBAL WARMING
Mostoftheclimatescientistsareagreethatthe
maincauseofthecurrentglobalwarmingisduetothe
"greenhouseeffect“
There may be other causes like
Respiration
Mining activities
Rapid industrialization
Increased in auto mobile use

5. GREEN HOUSE EFFECT
present in the atmosphere absorbs infrared radiations reflected from the surface
of the earth and heats up the atmosphere.

6. SOURCES OF GREEN HOUSE GASES

7. Sunlight’s energy remains trapped in the atmosphere

8. FLOODS & DROUGHTS
CAUSED BY GLOBAL
WARMING

9. DROUGHTS CAUSED BY GLOBAL
WARMING
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)

10. EFFECTS OF DROUGHTS TO
IRRIGATION
Amount of water in lakes, rivers, and streams
Crop Losses
Drying of Irrigation Canals
Affect the coastal Areas
Cause Heat Waves
Affect LiveStock

11. HOW FLOOD IS CAUSED BY
GLOBAL WARMING
Afloodis an overflow of water that submerges
land which is usually dry
The rate of evaporation from the ocean seems to be
increasing

12. EFFECTS OF FLOOD TO
IRRIGATION
Embankments of barrages and rivers
Damages underground piping system
Destroy agricultural crops
Affect the water table
Damage Head Canal
Affect whole Irrigation System

13. CASE STUDY OF 2010 FLOOD

14. DAMAGES OF 2010 FLOOD
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

15. CROPS DAMAGES OF 2010 FLOOD

16. IRRIGATION DAMAGES OF 2010
FLOOD

17. MAP OF FLOOD AFFECTED AREAS

18. LEVEL RISING TEMPERATURES OF
OCEANS /SEA
CAUSED BY GLOBAL WARMING

19. RISING TEMPERATURE OF OCEANS
AND SEA
Risingtemperatureofoceanandseamaybemoresignificant
thanthedirecteffectofhighertemperature.
Because….
•The world's agricultural output is heavily dependent on
irrigation.
•Out of a global cropped area of 1500million ha, 16%is
irrigated.
•Global warming is likely to have a major impact on the
hydrological cycle and consequently on irrigated agriculture.

20. 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.
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. :

21. 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
milesof the ocean.

22. RISING TEMPERATURE OF OCEANS
AND SEA
Saltwater intrusion
Sea-level rise can mean that saltwater intrudes into
groundwater drinking supplies, contaminates irrigation
supplies, or overruns agriculture fields.

23. RISING TEMPERATURE OF OCEANS
AND SEA

24. TORNADOES AND HURRICANES
CAUSED BY GLOBAL
WARMING

25. Tornadoes:
•A tornado is rapidly spinning air that develops from a
thunderstorms and is on the ground.
•Theingredientsforatornadoareathunderstorm,winds
changingspeedswithheightandrapidlyrisingair.
Hurricanes:
•Ahurricaneisahugeorganizedthunderstorm
complexthatdevelopsovertheocean
•Theingredientsarewarmoceanwater,weakupper
levelwinds,andlowpressure
TORNADOES AND HURRICANES

26. Comparison between Tornadoes and Hurricanes:
TORNADOES AND HURRICANES

27. HOW DO TORNADOES FORM?
The formation of tornadoes can be described into 3
steps:
1.Air Rotates Because of Wind Shear
2.Faster Spin Makes a Funnel Cloud
3.The Funnel Rotates and Touches Down

28. HOW DO HURRICANES FORM?

29. IMPACTS OF TORNADOES & HURRICANES
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.

30. IMPACTS OF TORNADOES & HURRICANES
An abnormal increase in the ocean's
level, sometimes in excess of several
meters high.
As hurricane winds, rainfall, and storm
surge cause direct and indirect effects
on the environment, this can also impact
agriculture.
Storm Surge: Impacts to Agriculture

31. MELTING OF GLACIERS
CAUSED BY GLOBAL
WARMING

32. MELTING OF GLACIERS

33. MELTING OF GLACIERS
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.

34. MELTING OF GLACIERS
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.

35. MELTING OF GLACIERS
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.

36. MELTING OF GLACIERS
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.

37. MELTING OF GLACIERS
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.

39. COSTAL EROSION AND ITS IMPACTS
ON IRRIGATION
CAUSED BY GLOBAL WARMING

40. COSTAL EROSION AND ITS
IMPACTS ON IRRIGATION
Erosion:erosionis the action of surface
processes such aswater floworwind
that remove soil,rock or dissolved
material from one location on
theEarth's crust thentransport it away
to another location.
Natural rates of erosion are controlled
by the action ofgeomorphicdrivers.

41. COASTAL EROSION
Coastal erosion, which
occurs on both exposed and
sheltered coasts, primarily
occurs through the action of
currents andwavesbut sea
level tidal change can also
play a role.

42. Cont:
Hydraulic actiontakes place when air in a joint is suddenly
compressed by a wave closing the entrance of the joint. This
then cracks it.
Wave poundingis when the shear energy of the wave hitting
the cliff or rock breaks pieces off.

43. Cont:
Coastal erosion can pose a
risk to residential
developments, roads,
lifeline utilities and coastal
structures and adversely
affect the irrigation water
and agricultural land.

44. IMPACTS OF COASTAL EROSION
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.

45. IMPACTS ON IRRIGATION
Increased salinity.
Enhanced waterlogging.
Reduction of irrigation water.
Increased Sedimentation.
Shrinkage of agricultural land.
Shortage of Food.

46. THANK YOU
EACH OF US MUST TAKE STEPS TO PROTECT OUR EARTH FROM GLOBAL WARMING