Assessing Access to Nature and Their Benefits in EJ Communities Across U.S. Cities with Geospatial Data

Spending time in nature enhances physical and mental health, but environmental and climate justice (EJ/CJ) communities are less likely to have access to nature. People with access to nature have lower blood pressure and reduced likelihood of mental health disorders, including depression. Natural areas also provide essential ecosystem services including carbon storage and sequestration, cooling, and stormwater capture. EJ/CJ communities are more likely to live in areas with limited access to natural areas, and are more susceptible to hypertension, diabetes, and asthma. Even when EJ communities are geographically close to natural areas, there often are physical, cultural, and social barriers to accessing and experiencing them.

With the U.S. urban population at 83%, natural areas in cities is how most people in the U.S. experience nature. Despite their human and environmental health benefits, there are no systematic assessments of natural areas in cities. Furthermore, lack of information about urban natural areas precludes an understanding of EJ and CJ communities’ access to nature. Synchronous with NASA's priorities, this project fills these two knowledge gaps by characterizing the amount and quality of urban natural areas with satellite remote sensing and assessing EJ communities’ geographic and perceived access to urban natural areas and their health benefits.

The project will be undertaken in 17 U.S. cities with in-depth work in 4 cities. It uses satellite data from Landsat, Sentinel-2, PlanetScope, and Worldview-2, and airborne imagery from the National Agriculture Imagery Program to create 1m to 30m multitemporal maps of urban nature. It uses publicly accessible socioeconomic and health data (redlining maps, U.S. Census, American Community Survey) and couples them with novel social science methods such as in vivo observations, community focus group discussions, and confidential surveys. We will create a HAVEN-MAP tool (Health, Access, Vulnerability, Equity, Nature-MAP) using Google Earth Engine to share project findings with end-users and the public.

The study objectives are:

1. Measure and quantify urban natural area land cover with multi-source, multi-resolution satellite data in 17 U.S. cities.
2. Model and measure the geographic access of EJ communities to urban natural areas and their climate, physical and mental health benefits in 17 U.S. cities.
3. Assess the perceived access of EJ communities to urban natural areas, including their socio-cultural and physical barriers in 4 U.S. cities.
4. Engage and collaborate with three nationwide end-user NGOs who work with underserved communities to improve access to nature, urban equity, and urban resilience: Forest in Cities, Resilient Cities Network (R-Cities), and the Trust for Public Land. The project has the potential to scale and inform EJ and CJ communities worldwide through R-Cities and its 100 partner cities in 40 countries by developing Earth science methods and products that can be replicated in other cities.