S. K. Dube & Tad Murty

1. Storm Surges in theBay of Bengal S. K. Dube & Tad Murty Indian Institute of technology Kharagpur

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

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

15. Meteorological Input Location Specific 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 Model

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

20. Orissa

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

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

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

26. Animation of Surge Evolution Associated with 1999 Orissa Cyclone