i this lecture you will learn about Disaster with the help of case study and you will know what are advantanges and disadvantages of disaster

1. Disaster
Made by Ar MWK

2. DISASTERS
Disaster is a natural or human, caused phenomenon, which causes serious disruption of the functioning of a
community or a society causing widespread human, material, economic and environmental losses which
elicited the ability of the affected community society to cope using its resources.
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3. TYPES OF DISASTERS
Three types of disasters are:
1.Natural - Hurricanes, tornadoes, earthquakes, floods,
volcanoes, etc.
2.Technological - Chemical releases, power outages,
natural gas explosions, etc.
3.Man-made - Terror attacks, race riots, mass shootings, etc

4. FLOODING
A flood is an overflow of water that
submerges land that is usually dry.
Flooding may occur as an overflow of
water from water bodies, such as
a river, lake, or ocean, in which the water
overtops or breaks levees, resulting in
some of that water escaping its usual
boundaries.
it may also occur due to an accumulation
of rainwater on saturated ground in an
areal flood.
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5. TYPES OF FLOODS
A flash flood occurs when runoff from
excessive rainfall causes a rapid rise in the
water height (stage) of a stream or
normally-dry channel. Flash floods are
more common in areas with a dry climate
and rocky terrain because lack of soil or
vegetation allows torrential rains to flow
overland rather than infiltrate into the
ground.
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6. TYPES OF FLOODS
River flooding is generally more
common for larger rivers in areas with
a wetter climate, when excessive
runoff from longer-lasting rainstorms
and sometimes from melting snow
causes a slower water-level rise over a
larger area. Floods also can be caused
by ice jams on a river or high tides,
but most floods can be linked to a
storm of some kind.
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7. CAUSES OF FLOOD
PHYSICAL
• Climatological
• Nature of drainage
• Coastal influences
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HUMAN
• URBANISATION
• DEFORSTATION

8. PHYSICAL CAUSE
• Intense rainfall (rainfall intensity >infiltration
capacity) – common in semi-arid areas
• Prolonged period of rainfall produces
saturation of the soil and overland flow
(widespread flooding in UK during summer
2007 was the result of the wettest summer
since 1766)
• A sudden increase in temperature producing
rapid snowmelt, which can be made worse
by frozen ground limiting infiltration
• (1995 Rhine flood in Germany and nether
land)
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9. NATURE OF DRAINGAGE BASIN
• Infiltration rate depend on
rock and soil.
• Shape of the river basin,
gradient and vegetation covers
affect how quickly run off
reaches the channel
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10. COASTAL INFLUENCES
• High seasonal tides,
Tropical cyclones can
result in higher water
levels in rivers and
low lying coastal
areas
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11. HUMAN CAUSES OF FLOOD
• DEFORESTATION
• Cutting of Trees (Lose of trees)
• Increase run-off
• Global warming
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12. • The creation of highly impermeable surfaces such
as roads, roof and pavements.
• Smooth surfaces served by a dense network of
drains, gutter and underground sewers,
effectively increasing drainage density.
• Straightening river channels and lining them with
concrete as part of building projects lead to faster
delivery of water downstream.
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HUMAN CAUSES OF FLOOD
• URBANISATION

13. BENEFITS OF FLOOD
Floodplains are dynamic natural systems. The natural
processes of periodic flooding, accompanied by
erosion and deposition, bring changes to the
topography, soils, vegetation, and physical features
(such as meanders, braided channels and oxbow
lakes) within these areas over time.
Floodplains provide a wide range of benefits to the
ecosystem and community that include:
-Flood storage and erosion control–offer a broad area
for streams and rivers to spread out and
accommodate temporary storage of flood water,
reducing flood peaks and erosion potential.
-Water quality maintenance – reducing sediment
loads, filtering nutrients and impurities, and
moderating water temperature
-Groundwater recharge 13
• Biological productivity – providing fertile soils with high rate
of plant growth and diversity, richer agricultural harvests,
and healthier forests.
• Habitat for a variety of fish and wildlife, including rare and
endangered species.
• Recreational opportunities – providing areas for active and
passive activities, supporting the economic base.
• Open space.

14. HISTORY OF FLOOD IN PAKISTAN
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The floods in Pakistan began in late July 2010, resulting
from heavy monsoon rains in the Khyber Pakhtunkhwa,
Sindh, Punjab and, Balochistan regions of Pakistan, which
affected the Indus River basin. ... The Pakistani economy
was harmed by extensive damage to infrastructure and
crops

15. CASE STUDY OF FLOOD IN SWAT DURING 2010-11
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16. INTRODUCTION
SWAT DISTRICT
Swat District is a district in Malakand Division of Khyber Pakhtunkhwa province in Pakistan. Swat is
renowned for its outstanding natural beauty.
Swat's average elevation is 980 m (3,220 ft),resulting in a considerably cooler and wetter climate
compared to most of Pakistan. With lush forests, verdant alpine meadows, and snow-capped
mountains, Swat is one of the country's most popular tourist destinations.
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17. HEADING 02
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18. THANK YOU