Gateway Cities Tree Canopy Improvement Project

Background

Following the launch of our Los Angeles County Tree Canopy Map Viewer, we conducted a series of tree canopy improvement projects in collaboration with Loyola Marymount University Center for Urban Resilience, Gateway Cities Government Council and TreePeople.

Gateway Cities are a number of cities located along the corridor between Long Beach Harbor and Downtown LA's warehouse district. These cities include some of LA's most socially underserved communities like Compton, Downey, and Cerritos.

Residents are often exposed above-average air and noise pollution from the busy traffic along this corridor. These cities are also homes to many financially burdened and working-class families. They deserve better living environment with more access to urban greenness.

Our approach

We adopted a data+survey approach in deciding which block groups or parcels will be prioritized in tree planting. The priority is co-determined by local residents and scientists specialized in urban greening and landscape improvement. Below is the steps we have taken:

• Tree Summit held for residents during community activities and other civic events to brief residents on the present situation of tree canopy coverage and what are the possible changes.

• Residents who attended the Tree Summit submit a response to a survey we designed to collect their preference on tree planting. Sample questions include

  • How important do you think to have trees or other types of shade at the bus stops?

• After collecting enough survey responses, we translate these opinions into quantifiable metrics (see a working sample for the City of Lynwood below)

• We use the responses of the survey to calculate weights for each metric and normalize the data

• A priority index is finally calculated based on the normalized weighted rating

Future Works

• Incorporating indicators of land surface temperature to better assess the impact of low access to urban greenness, especially the tree canopy coverage from the perspectives of environmental justice and public health