Floods and tsunami

Presentation

1. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Floods
PRESENTED BY: UZAIR SHAH
ROLL NO. 35
SUBJECT: ENVIRONMENTAL
GEOLOGY
DEPARTMENT OF GEOLOGY
AWKUM

2. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Table of content
•What is Flood?
•Causes of Flood
•Types of Flood
•Advantages and disadvantages of flooding
•Environmental impact of flooding
•Flooding precaution
•History of flood damage in Pakistan
•Province wise losses / damage due to rain –flood 2010
•TSUNAMI. What is tsunami?
•Causes of tsunami
•Earthquake generated tsunami
•Effects of tsunami:
•History of tsunamis in Pakistan/Arabian sea (1945)

3. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
What is flood?
It is a natural event or occurrence where a piece of land (or area)
that is usually dry land, suddenly gets submerged under water.
Some floods can occur suddenly and recede quickly. Others take days
or even months to build and discharge.
When floods happen in an area that people live, the water carries along
objects like houses, bridges, cars, furniture and even people. It can wipe
away farms, trees and many more heavy items.

4. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Causes of flood
Natural
Heavy rains
Melting of ice
Undersea earthquake
Marine landslip
Man-made
Bank erosion
Breach of
dam/barrage/embankment
RIVER FLOOD
A river flood occurs when water levels
rise over the top of river banks due to
excessive rain from tropical systems
making landfall, persistent
thunderstorms over the same area for
extended periods of time, combined
rainfall and snowmelt, or an ice jam.
COASTAL FLOOD
A coastal flood, or the inundation
of land areas along the coast, is
caused by higher than average
high tide and worsened by heavy
rainfall and onshore winds (i.e.,
wind blowing landward from the
ocean.
INLAND FLOODING
Inland flooding
occurs when moderate
precipitation accumulates over
several days, intense precipitation
falls over a short period, or a river
overflows because of an ice or
debris jam or dam or levee failure.
FLASH FLOODING
A flash flood is caused by
heavy or excessive rainfall in a
short period of time, generally
less than six hours
TYPES OF FLOODING

5. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Advantages and disadvantages of flooding:
Floods can bring both advantages and disadvantages to an
area.
Floods can deposit rich, fertile alluvium on agricultural areas.
Also, flood water can replenish/fill irrigation channels.
On the other hand floods can destroy food supplies, homes
and transport infrastructures.

6. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Environmental impact of flooding
It effects the:
•The health and wellbeing of wildlife and livestock.
•Riverbank erosion and sedimentation.
•The dispersal of nutrients and pollutants.
•Surface and groundwater supplies.
•And local landscapes and habitats.

7. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Floodingprecaution
Before the floods
•Know about your local
relief centers and
evacuation routes.
•Fold and roll up anything
onto higher ground (or
upper floors of your
home), including
chemicals and
medicines.
•Make sure everything
that is of importance is
secured (jewelry,
documents, pets, and
other valuables).
•Plant trees and shrubs
and keep a lot of
vegetation in
your compound if you
are in a low-lying area as
that can control erosion
and help soften the
speed of the flowing
water.
During the floods
•Turn off all electrical
appliance, gas, heating
and the like if there is a
bit of time.
•Leave the area before it
gets too late. Do not drive
through the water as
moving water can sweep
you away.
•Stay away from power
lines or broken power
transmission cables.
•Try to keep away from
flood water as it may
contain chemicals or
other hazardous
materials
After the flooding
•Make sure you have
permission from
emergency officers to get
back inside your house
•Clean the entire home,
together with all the
objects in itverywell
before you use them
again. They may be
contaminated.
•Wear appropriate gear
(mask and gloves)
before cleaning begins.

8. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
History of flood damage in pakistan
Year
Direct Losses
(US $ million)
Lost Lives Affected Villages
Flood Area
(Km
2
)
1950 227 2,910 10,000 17,920
1955 176 679 6,945 20,480
1956 148 160 11,609 74,406
1957 140 83 4,498 16,003
1959 109 88 3,902 10,424
1973 2,388 474 9,719 41,472
1975 318 126 8,628 34,931
1976 1,621 425 19,390 81,920
1977 157 848 2,185 4,657
1978 1,036 393 9,199 30,597
1981 139 82 2,071 4,191
1983 63 39 643 1,882
1984 35 42 251 1,093
1988 399 508 100 6,144
1992 1,400 1,008 13,208 38,758
1994 392 431 1,622 5,568
1995 175 591 6,852 16,686
1998 NA 47 161 NA
2001 NA 201 NA NA
2003 NA 230 NA NA
2010 10,056 1,985 17,533 160,000
2011 66 516 NA 9,098
Total 19,045 11,866 128,516 576,230

9. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
PROVINCE WISE LOSSES / DAMAGE DUE TO RAIN
–FLOOD 2010
Province /
Agency
Total
Affected
Districts
Cropped
Area
Affected
(Ha)
Population
Affected
(M)
Houses
Damaged
Road
Mileage
(Km)
Villages
Affected
Water
Courses
Damaged
Persons
Died
Persons
Injured
Punjab 11 746,9 9.20 375.773 2,819 1,778 2,598 110 262
Sindh 17 1,043,500 7.185 879,978 8,467 11,988 6,990 411 1,235
KPK 24 121,500 3.8 257,2946,511 544 1,790 1,068 1,198
Baluchistan 12 132,500 0.7 79,720 2,077 2,896 47 54 104
FATA - 7,220 * 5,419 1,257 * 0 * *
Gilgit
Baltistan
7 7,900 0.1 3,157 382 347 960 183 60
AJK 7 33,100 0.2 6,843 3,575 0 657 71 87
Total 78 2,092,60020.1851,608,18425,088 17,553 13,042 1,985 2,946

10. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk

11. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Tsunami

12. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
What is tsunami?
A tsunami is a series of waves created
when water is moved very quickly,
underwater earthquakes are the most
common causes of tsunamis, but
underwatered volcanic activity can also
trigger a displacement in the water, and
create a mega-wave.

13. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Causes of tsunami:
Volcanic eruptions
Icefalls
Seismic activities
Submarine landslides
Cosmic impacts

14. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Earthquake generated tsunami:
An earthquake may generate a tsunami
if the quake:
◦Occurs just below a body of water,
◦Is of moderate or high magnitude,
◦Displaces a large-enough volume of water.

15. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Effects of tsunami:
Damaging property
Loss of life
Flooding and contaminating of drinking water
Environmental impacts
Solid wastes and disaster debris
Radiation from nuclear plants
Psychological effect
Post traumatic stress disorder (PTSD)

16. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
History of tsunamis in Pakistan/Arabian sea
On December 26, 2004, a devastating severe earthquake (magnitude 9.0) occurred off the western coast of
Sumatra in the Indian Ocean.
The earthquake was caused by the release of stresses accumulated as the Burma tectonic plate overrides
the India tectonic plate.
Movement of the seafloor due to the earthquake generated a tsunami, or seismic sea wave, that affected
coastal regions around the Indian Ocean.
Though rare and relatively unheard of, tsunamis have struck the shores of Pakistan in the past.
The deadliest was in 1945 which originated off the Mekrancoast in Pakistan
Detail of Tsunami occurred in 1945 is appended below.
◦87.1 kilometers SSW of Churi (Balochistan), Pakistan,
◦97.6 kilometers SSW of Pasni (Balochistan),Pakistan,
◦98.5 kilometres SE of Gwadar (Balochistan), Pakistan,
◦408 kilometers W of Karachi (Sindh), Pakistan

17. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Cont.
The tsunami reached a height of 40 feet in some areas Makranports and caused great
damage to the entire coastal region.
The fishing village of Khudi, some 30 miles west of Karachi, was completely obliterated.
All the inhabitants and their huts were washed away.
Total causality was reported as around 4000.
At Karachi, the tsunami arrived from the direction of Clifton and Ghizri. It ran along the
oil installations at Keamariand flooded a couple of compounds. The waves were 6.5 feet
high in Karachi.

18. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk
Reference
http://www.climateinfo.pk/frontend/web/attachments/datatype/1.%20TSUNAMI%20DISASTER%20IN%20SOU
TH%20ASIA.pdf(Tsunami disaster in south Asia by Sarfaraz Shahid)
Physical Geology by Nicholas K.Cochand Allan Ludman

19. Abdul WaliKhan University MardanPakistan. www.awkum.edu.pk