S. K. DubeS. K. Dube&&

Tad MurtyTad Murty

Indian Institute of technology Kharagpur

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

Effect of local TidesEffect of local Tides

Effect of local Effect of local Coastal Coastal ConfigurationConfiguration

Low Atmospheric Pressure in the Centre

WindWind

Rain

Storm SurgeStorm SurgeStorm SurgeStorm Surge

FloodingFlooding

Loss of Loss of Human Human Life: Life: InjuriesInjuries

Loss of Loss of Human Human Life: Life: InjuriesInjuries

Damage to Damage to structures & structures & ContinentContinent

Damage to Damage to structures & structures & ContinentContinent

Flooding of Low-Flooding of Low-Lying Coastal AreasLying Coastal Areas

Flooding of Low-Flooding of Low-Lying Coastal AreasLying Coastal Areas

Erosion of BeachesErosion of Beaches

Damage to onshore Damage to onshore & offshore & offshore installationsinstallations

Damage to Shipping Damage to Shipping & Fishing Facilities& Fishing Facilities

Loss of Loss of Communications Communications & Power& Power

Urban Urban BushfireBushfire

Loss of Soil Loss of Soil Fertility Fertility from Saline from Saline IntrusionIntrusion

Land Land SubsidenceSubsidence

ContaminatiContamination of on of Domestic Domestic Water Water SupplySupply

Destruction Destruction of of Vegetation, Vegetation, Crops, Crops, LivestockLivestock

Potential Impact upon Landfall of a Tropical CyclonePotential Impact upon Landfall of a Tropical Cyclone

DEATHS IN TROPICAL CYCLONESYEAR COUNTRIES DEATHS1970 Bangladesh 300,0001737 India 300,0001886 China 300,0001923 Japan 250,0001876 Bangladesh 200,0001897 Bangladesh 175,0001991 Bangladesh 140,0001833 India 50,0001864 India 50,0001822 Bangladesh 40,0001780 Antilles(West Indies) 22,0001965 Bangladesh 19,2791999 India 15,0001963 Bangladesh 11,5201961 Bangladesh 11,4661985 Bangladesh 11,0691971 India 10,0001977 India 10,0001966 Cuba 7,1961900 USA 6,0001960 Bangladesh 5,1491960 Japan 5,0001972 India 5,000

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

Review of storm surges in theBay 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)

METHODS OF SURGE PREDICTIONMETHODS OF SURGE PREDICTION

EMPIRICAL MODELLINGIt is primarily based on correlations between the sea level and some Meteorological Parameter

Rao & Mazumdar (1966) Janardhan (1967) Rao (1968) Choudhary and Ali (1979) Qayyum (1983)

ANALYTICAL MODELLINGANALYTICAL MODELLING

Not possible without making major simplifying assumptions in Hydrodynamic Equations of Motion

–Das (1981)

NUMERICAL MODELLINGNUMERICAL MODELLINGDas (1972)Flierl & Robinson (1972)Das, Sinha and Balasubramanyam (1974)Ghosh (1977)Das (1980)Johns & Ali (1980)Htu Aung Cho (1980)Tun Lwin(1980)

Johns (1981)

Johns, Dube, Mohanty and Sinha (1981)

Jarrel, Lewis and Whitmaker (1982)

Johns, Dube, Sinha, Mohanty and Rao(1982)

Johns, Sinha, Dube, Mohanty and Rao(1983)

Johns, Sinha, Dube, Mohanty and Rao(1983)

Murty and Henry (1983)

Dube, Sinha, Lal and Rao (1984)

Dube, Sinha, Rao and Rao (1985)

Johns, Rao, Dube and Sinha (1985)

Dube, Sinha and Roy (1985)

Dube, Sinha and Roy (1985)

Dube, Sinha and Roy (1986)

Dube, Sinha and Roy (1986)

Dube, Sinha, Roy and Jaggi (1986)

Murty, Flather & Henry (1986)

Subramaniam, Mahadevan & Srinivasan(1989)

Dube and Rao (1991)

Flather and Khandker (1993)

Dube, Rao, Sinha and Chittibabu (1994)

Rao, Dube and Chittibabu (1994)

Flather (1994 )

Das (1994)

Tun Lwin(1994)

Ali (1996)

Dube, Rao, Sinha, Murty & Bahulayan (1997)

Rao, Chittibabu, Dube, Rao & Sinha (1997)

Henry, Duncalf, Walters, sborne & Murty (1997)

Ali, Rahman & Chowdhury (1997)

Chittibabu (1999)

Dube, Chittibabu, Rao, Sinha & Murty (2000)

Dube, Chittibabu, Rao, Sinha & Murty (2000)

Chittibabu, Dube, Rao, sinha & Murty (2000)

Real Ocean

Real Ocean Model

Mathematical ModelResults

Idealization & Approximation

Based on experience & understanding of the problem

Abstract symbolicRepresentationBased on Mathematical Experience

Solution based onMathematical Experience

COMPARISON

Location Specific InputMeteorological 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

IIT Storm Surge ModelIIT 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

OUTPUTOUTPUTOUTPUT

Sea-levels, Currents & Peak Surge Envelop for three Forecast Scenarios landfall at the forecast location

landfall at some distance (preferably 50 – 100 km) to the left of forecasted location

landfall to the right of the forecasted location

Display field in any order or combination from the menu

Zoom any part of the coastal region to get a clear picture if needed

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

SignificantSignificant FeatFeaturesures

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

Surge Envelope Scenario II: Landfall at Puri

Distance along East Coast of India (km)

Surge Envelope Scenario III: Landfall at Balasore

Distance along East Coast of India (km)

Andhra PradeshAndhra PradeshAndhra PradeshAndhra Pradesh

Track of 1990 Andhra Cyclone

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

§ Place of Landfall

Surge Envelope Scenario II: Landfall (100 km to left)

Distance along East Coast of India (km)Distance along East Coast of India (km)

Surge Envelope Scenario III: Landfall (100 km to right)

Distance along East Coast of India (km)Distance along East Coast of India (km)

Track of 1977 Andhra Cyclone

Peak Surge EnvelopeDistance along East Coast of India (km)

BangladeshBangladeshBangladeshBangladesh

BangladeshBangladeshBangladeshBangladesh

Track of 1970 Bangladesh Cyclone

Surge along Bangladesh Coast

Track of 1982 GWA Cyclone

MyanmarMyanmar

Peak Surge Envelope 1982 Cyclone

Track of 1964 Sri Lanka Cyclone

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

• 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

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

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