Housing & Transportation - Counties

What is CDC Social Vulnerability Index? ATSDR’s Geospatial Research, Analysis & Services Program (GRASP) created the Social Vulnerability Index (SVI) to help emergency response planners and public health officials identify and map the communities that will most likely need support before, during, and after a hazardous event. SVI uses U.S Census Data to determine the social vulnerability of every county and tract. CDC SVI ranks each county and tract on 16 social factors, including poverty, lack of vehicle access, and crowded housing, and groups them into four related themes: Theme 1 - Socioeconomic Status Theme 2 - Household Characteristics Theme 3 - Racial & Ethnic Minority Status Theme 4 - Housing Type & Transportation Variables For a detailed description of variable uses, please refer to the full SVI 2020 Documentation. Rankings We ranked counties and tracts for the entire United States against one another. This feature layer can be used for mapping and analysis of relative vulnerability of counties in multiple states, or across the U.S. as a whole. Rankings are based on percentiles. Percentile ranking values range from 0 to 1, with higher values indicating greater vulnerability. For each county and tract, we generated its percentile rank among all counties and tracts for 1) the sixteen individual variables, 2) the four themes, and 3) its overall position. Overall Rankings: We totaled the sums for each theme, ordered the counties, and then calculated overall percentile rankings. Please note: taking the sum of the sums for each theme is the same as summing individual variable rankings. The overall tract summary ranking variable is RPL_THEMES. Theme rankings: For each of the four themes, we summed the percentiles for the variables comprising each theme. We ordered the summed percentiles for each theme to determine theme-specific percentile rankings. The four summary theme ranking variables are: Socioeconomic Status - RPL_THEME1 Household Characteristics - RPL_THEME2 Racial & Ethnic Minority Status - RPL_THEME3 Housing Type & Transportation - RPL_THEME4 Flags Counties and tracts in the top 10%, i.e., at the 90th percentile of values, are given a value of 1 to indicate high vulnerability. Counties and tracts below the 90th percentile are given a value of 0. For a theme, the flag value is the number of flags for variables comprising the theme. We calculated the overall flag value for each county as the total number of all variable flags. SVI Informational Videos Introduction to CDC Social Vulnerability Index (SVI) Methods for CDC Social Vulnerability Index (SVI) More Questions? CDC SVI 2020 Full Documentation SVI Home Page Contact the SVI Coordinator