This project was developed out of research by University of California Cooperative Extension Specialists Luke Macaulay and Van Butsic at UC Berkeley’s Department of Environmental Science, Policy and Management Department.
UC Agriculture and Natural Resources Informatics and GIS Statewide Program developers Shane Feirer, Robert Johnson, and Andy Lyons developed the interface and website. The project was funded through a grant associated with the Renewable Resource Extension Act (RREA) administered by the U.S. Department of Agriculture’s National Institute of Food and Agriculture (NIFA).
Land cover data is derived from the USDA Cropland Data Layer
Ownership data: Parcel data was assembled for all 58 California counties. Parcel data with ownership information for 49 counties was derived from Boundary Solutions Inc., with the remaining nine counties assembled by contacting individual county governments. These county parcel data sets came from varying years, with 49 counties from 2011 to 2015 and nine counties from 2005 to 2010.
After assembling county parcel maps for the entire state, we then dissolved parcels by owner name within each county to remove interior borders of parcels owned by the same entity in the county and to calculate total area under each ownership. After this effort approximately 8% of the state had unknown ownership, so the authors overlaid three separate ownership maps that cover public land and conservation easements to assign ownership to parcels that did not have ownership information from original parcel data (CCED 2015; CDFFP 2014; CPAD 2015). This process reduced unknown ownership to approximately 2.7% of California's total land area (∼2.85 million acres). Ownership information has been left anonymous. The final ownership map was composed of approximately 543,495 properties greater than 5 acres across the state of California.
This study excluded properties smaller than 5 acres under the assumption that properties of less than 5 acres were not oriented towards production agriculture. Ownership statistics are heavily skewed to many small properties and few very large properties, and as such, acreage statistics are greatly affected by the cutoff value of the minimum size of cropland ownership (in this case 5 acres). Raising or lowering the minimum size property in the dataset increases or decreases the mean and median statistics correspondingly.
Researchers interested in collaborating to perform additional analyses of this ownership map can contact Luke Macaulay and Van Butsic.
Data download: Underlying ownership data in a format that can be read by the free statistical program R may be downloaded at this link. Metadata showing the year of the parcel data for each county’s information are provided below. These data only include properties that are greater than 5 acres.
Ownership boundaries are not intended to reflect legal rights, boundaries, and definitions. The data, information, and maps provided herein are part of a research project and are derived from various sources that do not guarantee accuracy, with errors possible in property lines. The Regents of the University of California (“the Regents”) and the developers of this site make no warranty, representation or guarantee as to the content, accuracy, timeliness or completeness of any of the information contained implied herein, and shall not be responsible for any errors or omissions. By using this site and the information contained on this site, you hereby release the Regents and developers of the site from any and all claims resulting from your use of this site or results obtained from the use of this information; and you agree to indemnify, defend and hold harmless the Regents and the developers of this site from and against any and all claims, liabilities, losses and expenses (including reasonable attorneys' fees) arising out of your use of this site and the information contained on this site.
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