A Comparison of Mapping Methodologies Identifying Transportation Disadvantaged Populations and Extreme Weather Risk

This analysis compares three increasingly granular mapping methodologies to predict where transportation disadvantaged (TD) populations live in the Boston area. The methods are as follows: (1) A standard choropleth method, which utilizes a binary system to determine levels of TD and a thematic shading symbology, (2) a dasymetric mapping method utilizing the Environmental Protection Agency’s Intelligent Dasymetric Mapping (IDM) Toolbox to redistribute population based on land use, and (3) a Cadastral-Based Expert Dasymetric System (CEDS) which utilizes parcel data to redistribute population and principal component analysis of vulnerability attributes. In addition to using these three methods to estimate TD population, this paper investigates vulnerability to extreme weather risk by estimating TD populations living within evacuation zones or within a reasonable walk to a shelter.The CEDS results suggest approximately 20% more people may require evacuation assistance than the Massachusetts Emergency Management Agency estimates. In total, 14% of the population in the study area (487,389 people) are at risk of being in a TD location, and of these people, 14% live within an evacuation zone and farther than a 20-minute walk from a potential shelter. In the future, planners could utilize this dasymetric mapping method, paired with outreach and training, to proactively plan for extreme weather events.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Maps; References; Tables;
  • Pagination: 17p

Subject/Index Terms

Filing Info

  • Accession Number: 01763890
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-00218
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 11:13AM