Redlining and its effects on biodiversity in Los Angeles County

About

Redlining refers to a practice by the Home Owners' Loan Corporation(HOLC) that dates back to the 1930's. The HOLC would rate neighborhoods (A - green, B - blue, C- yellow, or D - red) by "residential security" in various American cities. These ratings were often based on racial segregation and would then block access to loans for homeowners (Gee, G.C.). In this analysis we will explore the effects of redlining on health, economy, and environment today.

Highlights

• Map making using tmap
• Manipulating vector and raster data to build multi-layer maps
• Data visualizations using ggplot
• Custom warning messages

Repository Structure

|── holc-biodiversity 
|└── README.md
|└── holc-biodiversity.html
|└── holc-biodiversity,qmd  
|└── holc-biodiversity.Rproj
|└── holc-biodiversity_files
|  └── figure-html/
|    └── unnamed-chunk-4-1.png
|    └── unnamed-chunk-4-2.png
|    └── unnamed-chunk-4-3.png
|    └── unnamed-chunk-4-4.png
|    └── unnamed-chunk-7-1.png
|    └── unnamed-chunk-7-2.png
|  └── libs/
|    └── bootstrap/
|      └── bootstrap-icons.css
|      └── bootstrap-icons.woff
|      └── bootstrap.min.css
|      └── bootstrap.min.js
|    └── clipboard/
|      └── clipboard.min.js
|    └── quarto-html/
|      └── anchor.min.js
|      └── popper.min.js
|      └── quarto-syntax-highlighting.css
|      └── quarto.js
|      └── tippy.css
|      └── tippy.umd.min.js
|└── .gitignore  
|  └── data/ 
|  └── .Rproj.user
|  └── .Rhistory
|  └── .Rdata
|  └── .Ruserdata

Data

Three datasets were used in this analysis. The first dataset is form the United States Environmental Protection Agency’s EJScreen: Environmental Justice Screening and Mapping Tool. It provides environmental and demographic information for US Census tracts and block groups. It can be downloaded at the EPA website.

The second dataset is from the Digital Scholarship Lab at University of Richmond and can be downloaded here. It provides information on HOLC grades and we use it to determine grades in LA County.

The third dataset we worked with was from the Global Biodiversity Information Facility and provides information on bird observations in LA County.

References

1. Digital Scholarship Lab. Redlining Map Data (JSON file). University of Richmond, Digital Scholarship Lab. Accessed October 17, 2024.

2. Global Biodiversity Information Facility. (Data File) Available from https://www.gbif.org/ Access date: October 17, 2024.

3. United States Environmental Protection Agency. 2023. Data from: Geodatabase of National EJScreen Data at the Block Group Level

4. Gee, G. C. (2008). A multilevel analysis of the relationship between institutional and individual racial discrimination and health status. American journal of public health, 98(Supplement_1), S48-S56

5. Ellis-Soto, D., Chapman, M. & Locke, D.H. Historical redlining is associated with increasing geographical disparities in bird biodiversity sampling in the United States. Nat Hum Behav 7, 1869–1877 (2023). https://doi.org/10.1038/s41562-023-01688-5