Science activity

Agricultural lands are mapped in the state of California each year, beginning in 2014. In 2014, DWR contracted LandIQ to undertake a comprehensive mapping project for the the state of California. Field-scale assessment of agricultural land use and urban/managed wetland boundaries were determined, and these 2014 data are publicly available on the DWR Land User Viewer interactive map. Following this 2014 work, LanIQ was subsequrntly contracted to continue mapping in and around the state of California, focused on mapping agricultural lands only (2014-ongoing). Aerial imagery provided by the United States Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) was collected throughout the summer of 2014 by the USDA and used for field delineation, classification and QA/QC of the final product. Multiple Landsat 8 images were used for the initial crop classification. Imagery from the Landsat 8 satellite is free and available every 16 days and provided for temporal analysis throughout the growing season. Ground truth data were collected during the 2014 growing season prior to the initiation of this project. These data were used for training and validation of the mapping analysis. Field data from over 15% of all irrigated land in the Central Valley was collected. 25% of the ground truth data were set aside for independent validation. Analysis in areas that lacked ground truth data was performed using imagery and classification approaches established in areas that were informed by training data. (https://gis.water.ca.gov/app/CADWRLandUseViewer/images/i15_Crop_Mapping_2014_Final_Meta.pdf) (https://gis.water.ca.gov/app/CADWRLandUseViewer/)