Data and Code for 'Farm-scale inequality patterns of land ownership and groundwater access in California's Central Valley'

This repository contains the following datasets:

• 'cropland_parcels_filtered_owners_deidentified' : spatial data of parcel centroids with key metrics (parcel area, land value, etc.). Parcel data obtained from Regrid. Owner names, address information, etc. have been removed and polygons represented as centroid points for privacy reasons, as per Regrid policy
• 'final well-parcel matches, deidentified' : csv of final well-parcel matches with well metrics (well depth, capacity, etc.) and parcel metrics (parcel area, land value, etc.). Owner names, address information, etc. have been removed for privacy reasons as per Regrid policy
• 'filtered_gw_basins' : Spatial data of Central Valley groundwater subbasin boundaries from California Department of Water Resources (CADWR), download accessible here
  • Processed to include 1981-2023 mean annual precipitation by subbasin from CHIRPS
  • Joined with subbasin critically overdrafted status, as declared by CADWR, obtained from the SGMA Data Viewer
• 'central_valley_counties': Spatial data of Central Valley county boundaries, obtained from the tigris package in R
• 'depth_to_gw_points' : Spatial point data of depth to groundwater from Fall 2023, obtained from the SGMA Data Viewer, under 'Groundwater Levels' --> 'Seasonal Reports'
• 'filtered_PLSS_sections' : Spatial data of PLSS section boundaries that intersect Central Valley subbasins, obtained from the California Data Portal
• 'filtered_wells_with_section' : Spatial point data based on CA DWR's Online System for Well Completion Reports (OSWCR)
  • Joined with standardised well data from the US Groundwater Database (USGWD) and filtered for wells that intersect Central Valley subbasins
• 'sw_districts_filtered' : Spatial data of boundaries for public water districts or private trusts that we assume likely have surface water access. We obtained these boundaries from the SGMA Data Viewer under 'Reference Layers' --> 'Water Agencies'
• 'crops_3311' : raster data of 2023 land use from the Cropland Data Layer

The repository also contains the following code, which is also available in the Github repository linked below:

• 'regrid_processing_analysis.Rmd': walks through all cleaning and processing of the above datasets in order to match groundwater wells with cropland parcels and calculate total cropland and groundwater ownership metrics needed for analysis and visualisations
• 'regrid_analysis.Rmd': walks through all descriptive & statistical analysis, as well as creation of all visualisations and tables, included in the manuscript and supplementary materials