California Food Access (LILA-style) — 2024 (Census Tracts, 2020 boundaries)

California Food Access (LILA-style) — 2024 (Census Tracts, 2020 boundaries) Overview. This record provides a 2024 update of “low access” (LA, often called “food desert” access) for California at the census-tract level on 2020 tracts. The method adapts USDA ERS Food Access concepts but is an independent update (not an official USDA product). Method (summary). Analysis grid: 500 m cells; distances computed from cell centroids to nearest qualifying SNAP retailer(supermarkets/large groceries). Urban/rural rule: UAC20 (2020 Census Urban Areas). Thresholds: >1 mile if urban; >10 miles if rural. Aggregation: cell-level “far” population summed to tracts; outputs in EPSG:3310. Key fields: far_pop_1_10_2024: people farther than the 1/10-mile rule far_share_2024: far_pop / tract_pop la_2024: 1 if far_pop ≥ 500 or far_share ≥ 0.3333 QA fields: nearest_store_dist_mi_2024, n_cells_2024, far_share_unweighted_2024, method_ver Store filter: include NAICS 445110 / store_type ∈ {Grocery Store, Supermarket, Super Store} and major chains; exclude convenience, gas, dollar, pharmacy, liquor. Distance type: Euclidean. No TDLinx used. What’s included (single-layer package). GeoPackage: ca_food_access_2024_v1.gpkg → layer la_tracts_2024 (tract polygons + fields above) GeoJSON (attributes only): ca_food_access_2024_tracts.geojson CSV (attributes only, join on geoid20): ca_food_access_2024_tracts.csv checksums.txt (SHA-256 for file integrity) Intended use. Mapping, public-health and planning analyses, and research that needs a current, transparent LA flag on 2020 census tracts. Results are best interpreted comparatively; Euclidean distances may understate network travel times. Notes & limitations.Aggregated at tract level (no PII). Independent update; not endorsed by USDA/ERS. Differences vs. ERS Atlas arise from 2020 tracts, UAC20, SNAP-only store sources, and Euclidean distances. Low-income overlays (LILA/LILATracts) are not included in v1.0. How to cite.Mendoza, G. A.; Central California Health Foundation (2025). California Food Access (LILA-style) 2024 — Census Tracts (2020 boundaries). v1.0.0. DOI: https://doi.org/10.5281/zenodo.17128076. CC BY 4.0. Keywords: food access, food deserts, California, census tracts, SNAP, public health, GIS, UAC20, 2024.