People’s Climate March NYC 2014. Photo: Susan Melkisethian

The intersection of geospatial information and issues of environmental justice is a rapidly expanding field, with an increased level of interest in recent years. A variety of tools exist at a local and national scale looking to map — and ultimately improve — issues of Diversity, Equity, Inclusion, and Justice throughout various avenues of conservation work. Many of these tools pull from similar sources of information. Below, we take a look at three commonly used sources of geospatial environmental justice data, and explore further what kinds of information they provide that go into the day-to-day work of solving issues of environmental inequity.

“A map does not just chart, it unlocks and formulates meaning; it forms bridges between here and there, between disparate ideas that we did not know were previously connected.”1


The Environmental Protection Agency’s EJSCREEN is an environmental justice mapping and screening tool that provides EPA with a nationally consistent approach for combining environmental and demographic indicators. EJSCREEN users choose a geographic area; the tool then provides demographic and environmental information for that area. All of the EJSCREEN indicators are publicly-available data, EJSCREEN simply provides a way to display this information. It can show reports and maps for each environmental indicator or demographic indicator, and includes a method for combining demographic indicators with single environmental factors into EJ indexes for populations residing in Census block groups. EJSCREEN includes:

  • 11 environmental indicators, from air quality to lead paint, waste, and water quality;
  • 6 demographic indicators, such as income, race, language, education, and age;
  • 11 EJ indexes such as cancer risk, toxics exposure, or proximity to traffic. Each EJ index combines demographic indicators with a single environmental indicator.

This tool provides a number of capabilities including:

  • Color coded mapping
  • The ability to generate a standard report for a selected area
  • Comparisons showing how a selected area compares to the state, EPA region or the nation.
A sample of the map data available — here, comparing traffic proximity and volume in areas of poverty in the DC area. Image: EJSCREEN

American Community Survey

The American Community Survey (ACS) is an ongoing survey that provides vital information on a yearly basis about our nation and its people. Every year, the U.S. Census Bureau contacts over 3.5 million households across the country to participate in the American Community Survey. Through the ACS, we know more about jobs and occupations, educational attainment, veterans, whether people own or rent their homes, and other topics. Public officials, planners, and entrepreneurs use this information to assess the past and plan the future.

Social Vulnerability Index

Social vulnerability refers to the potential negative effects on communities caused by external stresses on human health. Such stresses include natural or human-caused disasters, or disease outbreaks. Reducing social vulnerability can decrease both human suffering and economic loss.

The Social Vulnerability Index from the Centers for Disease Control / Agency for Toxic Substances and Disease Registry (CDC/ATSDR SVI) uses 15 U.S. Census variables to help local officials identify communities that may need support before, during, or after disasters. These include factors such as:

  • Socioeconomic status (below poverty, unemployed, income, no high school diploma)
  • Household composition & disability (aged 65 or older, aged 17 or younger, older than age 5 with a disability, single-parent households)
  • Minority status & language (minority, speak English “less than well”)
  • Housing type & transportation (multi-unit structures, mobile homes, crowding, no vehicle, group quarters)

The CDC/ATSDR SVI is updated every two years based on U.S. Census Bureau data releases. The Census releases American Community Survey data in December of the year following the Survey.

“Most of the world will make decisions by either guessing or using their gut. They will be either lucky or wrong.” 2

How does this data affect conservation?

These are foundational data sources that provide the key variables for environmental justice information and the stories that can be told from the data. The sources described here are not the only data sources, but three of the major ones upon which a lot of the different tools are built. And the tools are used for decision support, primarily. They can help to focus decisions, efforts and funding by answering questions such as: Where are there gaps in green space relative to communities, so those areas can be prioritized for resources to make green space available? Where can environmental improvements, green infrastructure, or changes in planning help to improve health in communities? The tools can help to identify communities in need of more shade to combat heat island effect; or map historically important sites to protect and/or that need resiliency planning assistance because they’re vulnerable to flooding. These data sets and tools help chart the course for conservation.

Examples of current projects that are providing powerful tools from data, with maps and analytics to help with decisions, include:

  • Our own Chesapeake Conservation Atlas, a series of conservation mapping analyses to inform conservation planning for the future.
  • The Maryland Park Equity Mapper, a state-specific tool built from the EJSCREEN that uses additional social and health factors in looking at quality of green space for more ‘traditional’ recreation as well as nature-based recreation. This tool could be replicated in other states.
  • The Mapping Inequality Project: America’s history of redlining and how it has resulted in poor environmental conditions in communities of color, for example the correlation of heat island effect in low-income areas that lack tree canopy.
  • American Forests Tree Equity Mapper, that “helps ensure everybody benefits from the power of trees to fulfill our basic needs, such as breathing fresh air and drinking clean water.”
Historic redlining practices in many cities continue to manifest inequities in terms of environmental quality and more. Analyzing the maps and correlation can help to target where remediation and restoration is needed to provide healthier communities for all.
Image: Mapping Inequality Project website.

While the three main data sources presented here in no way encapsulate all of the geospatial information on environmental justice that is available, they stand as a popular and foundational set of data for this work, and they inform and help to create a wide variety of decision-support tools that bring together otherwise seemingly disparate (though actually very connected) social, health, and environmental factors. As the field continues to expand, having Chesapeake specific equity data, such as the Chesapeake Bay Environmental Justice and Equity Dashboard, will be key to solving the Bay region’s own problems surrounding environmental justice and equitable access to nature as a whole.

It’s up to us to utilize these resources to maximize their benefits.

“Things get done only if the data we gather can inform and inspire
those in a position to make a difference.” 3

1Reif Larsen, The Selected Works of T.S. Spivet (2009), a novel about a 12-year old cartographer and technical illustrator from Montana, i.e., a naturalist.
2Suhail Doshi, chief executive officer, Mixpanel.
3Mike Schmoker, Results: the Key to Continuous School Improvement (1999). Schmoker is recipient of the Distinguished Service Award by the National Association of Secondary School Principals for his publication and presentations, ranked among the best sources of “practical advice, wisdom and insight” on effective school improvement.

Don’t forget to send us your 2020 land conservation success stories as they develop. They’ll land in the new and growing collection at, a tool we can all use to show collective impact. See the checklist below for easy-to-follow, simple guidelines.