Caribbean Tropical Cyclone Modeling

Transcription

1 Caribbean Tropical Cyclone Modeling Filmon Habte, PhD 2018 RAA Catastrophe Risk Management Conference Orlando, Florida February 14, 2018

2 Agenda Hurricane risk in the Caribbean 2017 hurricane season Lessons from KCC post disaster surveys KCC Tropical Cyclone Reference Model for the Caribbean 2

3 Hurricane Risk In the Caribbean ~ 2.5 Hurricanes per year ~ 1.9 Hurricanes per year affect at least one Caribbean island 21 CAT 4 and CAT 5 Hurricanes in the Caribbean Since 2000 Different islands have different vulnerabilities based on economics, building practices, etc. 3

4 The 2017 Hurricane Season 5 th most active season since 1851 Highest number of major hurricanes since 2005 Costliest season in the Caribbean 3 Tropical Storms (Phillippe, Bret, Harvey) impacted Caribbean Islands Jose 2 Landfalling Major Hurricanes (Maria and Irma) resulted in extensive damage throughout the Caribbean 1 Major Hurricane (Jose) passed just to the north of the Leeward Islands 4

5 Hurricane Maria (2017) in the Caribbean Second Category 5 hurricane to impact the Leeward Islands within a month Maria intensified from CAT1 to CAT5 in 15 hours (Second to Hurricane Wilma) Wide divergence in modeler loss estimates Initial Modeler Estimates of Maria Losses in PR 5

6 KCC Hurricane Maria Modeled Insured Losses in the Caribbean Puerto Rico United States Virgin Islands Dominica Guadeloupe Dominican Republic Martinique British Virgin Islands Saint Lucia $26500 M $800 M $400 M $35 M $10 M $8 M $5 M $3 M Majority of loss in Puerto Rico was to commercial structures KCC conducted detailed damage survey in Puerto Rico Comparison of Modeled and PCS Losses for Puerto Rico LOB KCC Modeled Loss PCS Losses AUT $0.32 B $0.37 B Antigua and Barbuda St Kitts and Nevis $2 M $1 M COM IND $21 B $2.78 B $19.2 B Sint Maarten Saint-Martin $1 M $1 M RES $2.40 B $2.36 B 6

7 KCC s Hurricane Maria Post Disaster Survey in Puerto Rico Independent damage survey Arecibo San Juan Fajardo Humacao Ponce Post Disaster Survey Survey and discussion with claims adjustors Review of actual claims files 7

8 Residential Building Damage Varied by Building Type 8

9 Residential Reinforced Concrete Buildings Performed Well Wall stucco damage and peeling paint Water infiltration induced damage Damage to doors and windows Damage to lighting fixtures Damage to sheds, fences and gates 9

10 Roof Tiles on Concrete Slabs Vertical Wind Profile 10

11 Wood-Frame and Mixed Construction In mixed construction, damage limited to the wood frame part Wood frame buildings performed poorly Corrugated zinc sheet roofs performed poorly 11

12 Wood-Frame and Mixed Construction in Low Wind Speeds 12

13 Different Commercial Constructions and Occupancies were Surveyed Schools and Universities Airport Restaurants Retail Stadiums and Sport Arenas 13

14 Observed Relative Vulnerability of Commercial Buildings Gas Stations performed poorly Low-rise RC apartments performed well 14

15 Low and Mid-Rise Apartments and Condos A significant portion of the low-rise apartment buildings in Puerto Rico are constructed using reinforced concrete, hence they experienced minimal structural damage Damage to Balcony Elements Damage to Decorative Tile 15

16 High-Rise Apartments and Condos Steel frame structures with EIFS cladding Frequent damage to balcony doors and windows was observed Most of this damage occurred because of weak door/window wall frame systems 16

17 Low-Rise Office Buildings Many low-rise offices experienced damage to EIFS and stucco claddings Significant damage to windows, including their frames 17

18 High-Rise Office Buildings Damage to cladding of tall buildings constructed with glass Damage due to high pressure Damage to mechanical systems including elevators 18

19 High-Rise Office Building Interior Damage Estimated total cost to repair ~ 25% of building value Insurers pay financial loss i.e. the cost to repair (usually higher than new construction) 19

20 Chain Pharmacies, Restaurants, Malls and Shopping Centers in Low Speeds Damage to such structures was prevalent, even in low wind speeds Low-quality of building finishing and lack of attention to details were observed 20

21 Chain Pharmacies, Restaurants, Malls and Shopping Centers in High Speeds Even small roof, wall or window openings can lead to heavy building interior and contents damage 21

22 Limited Damage to Industrial Buildings Damage limited to steel structures with metal roofs 22

23 Damage to Sources of Renewable Energy The wind turbines became operational in 2012 were designed to withstand wind gusts of 134 mph More than 70% of the solar panels experienced significant damage Punta Lima Wind Farm Fonroche Solar Farm 23

24 Caribbean Hurricane Loss Model Framework 24

25 Historical Hurricanes in the Caribbean Basin Since

26 Characteristic Event (CE) Approach for Catalog Generation The basin is divided into regions and historical hurricane data are analyzed separately for each region Each event in a region is assigned appropriate parameters defining the characteristics of that region (i.e. Characteristic Events) including Maximum wind speed (Vmax) Radius to maximum speed (Rmax) Forward speed Track A rate is assigned to each event 26

27 Maximum Wind Speed (Vmax) Each hurricane is assigned a Vmax based on its return period and region The chart below shows the historical data (blue diamonds) along with the Vmax selected for the return period events (red squares) for one region CE s corresponding to 3, 4, 5, 10, 20, 50, 100, 250, 500 years are derived 27

28 Modeling of Storm Tracks Primary track is the most typical track for that region There must be a smooth transition between tracks Enables robust calculations of Average Annual Losses (AALs) and loss costs at high resolution, including location level 28

29 Caribbean and US Models are Integrated A proportion of tracks impact the Caribbean and the US Hurricane San Felipe II / Okeechobee (1928) 29

30 Validation of Event Magnitudes and Rates TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 TS CAT1 CAT2 CAT3 CAT4 CAT5 30

31 Generation of the Hurricane Windfield The Willoughby wind profile model used to develop the windfield Asymmetry in the windfield dependent on the forward speed and wind inflow angle Asymmetry in the wind profile Inflow Angle 31

32 Addressing Effect of Surface Roughness and Local Topography Surface Roughness Land Use Land Cover Data Develop effective roughness lengths Surface Roughness N Topography N Direction dependent surface friction factors Local Topography High resolution elevation data (30 m) E E Direction dependent topography factors S S 32

33 Validation of Hurricane Footprints Wind speed are limited and observations need to be standardized before used Wind observations can have errors of 10-15% Anemometers fail at high wind speeds Hurricane Ivan (2005) Hurricane Georges (1998) Hurricane Marilyn (1991) Hurricane Hugo (1989) 33

34 VULNERABILITY Vulnerability Relativities Between Different Islands Building stock Type of buildings Construction practices Year built Building codes and enforcement Economic level Haiti : : : Dominican Republic Jamaica : : USVI and Bahamas : : Puerto Rico 34

35 Hurricane Maria and Hurricane San Felipe II (1928) Comparison Hurricane San Felipe II (1928) CAT 5 at landfall Modelled loss ~ $25.5 Billion Hurricane Maria (2017) CAT 4 at landfall Modelled loss ~ $26.5 Billion 35

36 Summary and Conclusion The Caribbean Region is highly active with respect to tropical cyclone frequency and severity Hurricane Maria clearly illustrated the differences in the vendor models and loss estimates In Puerto Rico, commercial properties dominate the insured loss potential The KCC Tropical Cyclone Reference Model for the Caribbean produces credible and reliable EP curves as well as accurate loss estimates for actual events 36