Identifying Vulnerable Populations to Hurricanes in the city of Tampa, FloridaDr. Jennifer Collins and Dustin Hinkel

Department of Geography, The University of South Florida

The 2004 and 2005 Hurricane seasons were record breaking seasons in terms of frequency and magnitude of hurricanes. These seasons have also brought a renewed examination of the issue of social vulnerability compounding geophysical vulnerability. Examples from Hurricanes Charley and Katrina have displayed to the world how certain factors of social vulnerability, like poverty, race, homeowner status, family size, and age, can augment the effects of hurricanes for certain populations within affected cities. To properly identify vulnerable populations in the city of Tampa, Florida a review of the literature was conducted to determine a methodology.

•Conduct a review of the vulnerability literature•Identify an area of study

•Collect demographic and geographic data•Research the area’s history with hurricanes

•Create a social vulnerability profile•U.S. Census Bureau data describing indicators discovered in the literature review

•Create a physical vulnerability profile•Overlay hazards maps onto the city map to determine geophysical vulnerability

•Create a total vulnerability profile•Combination of the Social and Physical vulnerability profiles

INTRODUCTION

METHODOLOGY

Geographic Information Systems is a powerful tool for emergency managers. This simple tool can help managers identify areas of a community that are especially vulnerable to hurricanes. This project highlights the importance of social vulnerability in assessing the total vulnerability of a community. The social and total vulnerability profiles indicate the extreme vulnerability of areas like downtown Tampa and Ybor City despite their moderate physical vulnerability. These areas are economically important to the city of Tampa and deserve the full attention of emergency managers and policymakers to alleviate the areas’ extreme social vulnerability.

CONCLUSION

STUDY AREA

The city of Tampa, Florida is a dense, urban city on the central Gulf Coast of the state of Florida. The city is culturally and ethnically diverse and a center of commerce for the Tampa Bay area. Tampa is situated along the coast of Hillsborough County and accounts for nearly 30% of the county’s total population. The city of Tampa and its 303,447 residents have enjoyed good fortune in dodging hurricanes for over eighty years. Tampa has been threatened numerous times from hurricanes and tropical storms as 60 storms have come within 75 mi of the mouth of Tampa Bay in the last 100 years.

The last hurricane to directly impact the Tampa Bay area was the unnamed storm of 1921. In October of 1921 the estimated category 3 storm made landfall just north of Tampa Bay, battered the city with winds exceeding 100 mph, and created a 10 to 12 ft storm surge in the Bay. The storm caused between one and ten million dollars worth of damage and was responsible for six deaths.

Acknowledgements

This project is the result of continuing research first conducted with the USF Hurricane Research Experience for Undergraduates (REU). We would like to thank all those who were involved with the REU from the USF Honors College and the REU faculty.

The 2005 Hurricane Season had an influential role in highlighting the critical nature of vulnerability to hurricanes. The world watched in horror as socially vulnerable groups struggled to cope with and recover from the effects of the hurricanes. The new challenge to emergency managers is to identify similar vulnerable populations in their areas before a hurricane strikes. The aim of this project is to use geographic information systems (GIS) to identify vulnerable populations within the city of Tampa (a city that has not had a direct impact from a hurricane in over 80 years).

ABSTRACT PHYSICAL VULNERABILITY PROFILE

The physical vulnerability profile was created using hazard maps and overlay operations in the ArcGIS software to spatially identify areas of physical vulnerability in the city of Tampa. FEMA Q3 flood maps were used to find areas vulnerable to flood damage. Areas at greatest risk to flooding were given a score of 4 and least vulnerable areas were given a score of 1. A storm surge map was used to find vulnerability to storm surge in the city. Areas at risk of experiencing storm surge from a tropical storm were given the highest score of 5 and areas at no risk to storm surge were given a score of 0. A HAZUS Wind Envelope map was used to identify areas at risk to high wind damage. Areas at highest risk were given a score of 4 and all others received a score of 3.

TOTAL VULNERABILITY PROFILE

The total vulnerability profile was created through the summation of the social and physical vulnerability scores of each of the 103 census tracts. The least vulnerable areas to hurricanes are the New Tampa area and on the central peninsula. These are areas that have a very low occurrence of factors that increase social vulnerability (like poverty and low education). The most vulnerable areas to hurricanes are located in downtown Tampa and Ybor City. These areas have high social vulnerability despite their moderate physical vulnerability.

SOCIAL VULNERABILITY PROFILE

• 103 census tracts in the city of Tampa, FL• 23 social vulnerability indicators

• Described both factors that increase social vulnerability, like renter-occupied housing units, race, age, and poverty status, and factors that decrease social vulnerability, like college education and income.

• Risk scores • Unique for each indicator• 4 classes

• Tracts with the highest concentration of an indicator received a score of 4 and tracts with the lowest concentration received a score of 1

• Total social vulnerability profile• Summation of risk scores of all 23

indicators for all 103 census tracts

Tampa_2000_Clip

TotalSocVu

12 - 19 Lowest Vulnerability

20 - 28 Low Vulnerability

29 - 37 Medium Vulnerability

38 - 46 High Vulnerability

47 - 54 Highest Vulnerability

2000 U.S. Census Bureau Tracts of the City of Tampa, FL

Tampa_2000_Clip

TotalPhysV

8 - 9 Lowest Vulnerability

10 - 11 Low Vulnerability

12 - 13 Medium Vulnerability

14 - 15 High Vulnerability

16 - 17 Highest Vulnerability

HAZUS Wind Envelope Map - Hillsborough County, FLFEMA Q3 Flood Map - Hillsborough County, FLStorm Surge Map - Hillsborough County, FL

Tampa_2000_Clip

TotalVuln

20 - 22 Lowest Vulnerability

23 - 38 Low Vulnerability

39 - 47 Medium Vulnerability

48 - 57 High Vulnerability

58 - 67 Highest Vulnerability