Storms and cyclones

1. S. K. Dube
&
Tad Murty
Indian Institute of technology
Kharagpur

2. Highlight the current activity in
surge modelling and related area in
the Bay of Bengal
Describe the development of
location specific real time stand
alone prediction system for
providing effective and timely surge
forecasts

3. Effect of local Tides
Effect of local
Coastal
Configuration
Low Atmospheric
Pressure in the Centre
Wind
Rain
Storm Surge
Flooding
Loss of
Human
Life:
Injuries
Damage to
structures &
Continent
Flooding of Low-
Lying Coastal Areas
Erosion of Beaches
Damage to onshore
& offshore
installations
Damage to Shipping
& Fishing Facilities
Loss of
Communications
& Power
Urban
Bushfire
Loss of Soil
Fertility
from Saline
Intrusion
Land
Subsidence
Contaminati
on of
Domestic
Water
Supply
Destruction
of
Vegetation,
Crops,
Livestock
Potential Impact upon Landfall of a Tropical Cyclone

4. DEATHS IN TROPICAL CYCLONES
YEAR COUNTRIES DEATHS
1970 Bangladesh 300,000
1737 India 300,000
1886 China 300,000
1923 Japan 250,000
1876 Bangladesh 200,000
1897 Bangladesh 175,000
1991 Bangladesh 140,000
1833 India 50,000
1864 India 50,000
1822 Bangladesh 40,000
1780 Antilles(West Indies) 22,000
1965 Bangladesh 19,279
1999 India 15,000
1963 Bangladesh 11,520
1961 Bangladesh 11,466
1985 Bangladesh 11,069
1971 India 10,000
1977 India 10,000
1966 Cuba 7,196
1900 USA 6,000
1960 Bangladesh 5,149
1960 Japan 5,000
1972 India 5,000

5. Factors Contributing to Disastrous Surge in
the Bay of Bengal
• Convergence of the Bay
Large bottom friction
• Shallow Water
Retards return undercurrent
• Thickly Populated Low Lying Islands
(Ramgati, Sandwip, Hatiya, Bhola & Kutubdia)
• High Astronomical Tides
• Inlets & Estuaries

6. Review of storm surges in the
Bay of Bengal
Ali (1979)
Rao (1982)
Roy (1984)
Murty (1984)
Murty et al. (1986)
Das (1994)
Dube et al. (1997, 1999, 2000, 2001)
Chittibabu (1999)

14. Real Ocean Real Ocean Model
Mathematical Model
Results
Idealization & Approximation
Based on experience &
understanding of the problem Abstract
symbolic
Representation
Based on
Mathematical
Experience
Solution based on
Mathematical Experience
C
O
M
P
A
R
I
S
O
N

15. Location Specific Input
Meteorological Input
Oceanographic &
Hydrological Input
Dynamic Storm Model
Wind Stress Associated with Cyclones
Storm Surge Model Equations
•Vertically Integrated Mass Continuity (1)
•Vertically Integrated Momentum (2)
Numerical Solution
Results
•Sea Surface Elevations
•Extent of Coastal Inundation

16. IIT Storm Surge Model
Operating Procedure
 Setup forecast domain by executing an appropriate
window
 Provide an arbitrary number of stations around the
forecasted place of landfall of the cyclone for peak
surge display
 Provide duration of forecast
 Provide tropical cyclone characteristics
(preferable six hourly observations)
 Cyclone positions (lat – long)
 Pressure Drop (Hpa)
 Radii of Maximum Winds (m)
 Run storm Model & Surge Model

18. Ability to investigate multiple
forecast scenario in real time
Updates cyclone track as the
cyclonic storm approaches
the coast and meteorological
forecast become more accurate
Significant
Features

23. Surge Envelope Scenario I: Actual Landfall
Distance along East Coast of India (km)

24. Surge Envelope Scenario II: Landfall at Puri
Distance along East Coast of India (km)

25. Surge Envelope Scenario III: Landfall at Balasore
Distance along East Coast of India (km)

63. Andhra Pradesh

64. Track of 1990 Andhra Cyclone

65. Surge Envelope Scenario I: Actual Landfall
Distance along East Coast of India (km)
§ Place of Landfall

66. Surge Envelope Scenario II: Landfall (100 km to left)
Distance along East Coast of India (km)

67. Surge Envelope Scenario III: Landfall (100 km to right)
Distance along East Coast of India (km)

68. Track of 1977 Andhra Cyclone

69. Peak Surge Envelope
Distance along East Coast of India (km)

70. Bangladesh

71. Bangladesh

72. Track of 1970 Bangladesh Cyclone

73. Surge along Bangladesh Coast

76. Track of 1982 GWA Cyclone

77. Myanmar

78. Peak Surge Envelope 1982 Cyclone

79. Track of 1964 Sri Lanka Cyclone

81.  A real time storm surge prediction systems
is proposed for India, Bangladesh, Myanmar
& Sri Lanka, which can be run in a few
minutes on a PC
 Only meteorological inputs required for the
model are positions of the cyclone, pressure
drop and radii of maximum winds at any
fixed interval of times

82. • The system is operated via a terminal menu
and the output consists of the 2-D and 3-D
views of peak sea surface elevations with the
facility of zooming the region of interest
• The system can handle multiple forecast
scenarios
• The model has extensively been tested with
severe cyclonic storms of the last three
decades, which have affected the coastal
regions in the Bay of Bengal

83. Global Storm Surges:
Theory, Observations and Applications
G. Gönnert, S. K. Dube, Tad Murty and W. Siefert
CONTENTS
Introduction and General
Considerations
The Basic Storm Surge Equations and
Standard Methods of Solutions
Finite Element Models
Special Hydrodynamic Problems
Meteorological Aspects
Storm Surges Generated by Tropical
Cyclones - Case Studies
Storm Surges generated by
Extratropical Cyclones - Case Studies
Impact of Climate Change and Sea level
Rise on Storm Surges
Die Küste Germany, 2001

84. `