Description: <p>Publicly available field boundary datasets were collected from state and federal agencies and the 2008 USDA Common Land Unit (CLU) database. These datasets have been filtered to remove overlapping and redundant polygons, as well as very small slivers (<0.25 acres) and very large polygons associated with grazing on non-irrigated rangelands and shrublands. Priority was given to more recent field boundary datasets produced by each state, and the CLU data were used only in cases where no state or local level datasets are publicly available. </p> <h2>About Crop Type Information</h2><p>The crop type information available on this site is from publicly available datasets, and does not have a meaningful effect on the accuracy of the ensemble ET value, or the five models that use thermal infrared data as an input for calculation of ET (ALEXI/DisALEXI, eeMETRIC, geeSEBAL, PT-JPL, SSEBop). The SIMS model does use crop type information to separate annual and perennial crops, and to adjust model parameters for perennial crops. Errors in crop type classification for annual crops do not affect the SIMS ET calculations, and the crop-specific adjustments for perennials usually have a small influence on SIMS ET relative to other inputs. In rare cases where crop type errors do have an effect on SIMS ET data, SIMS is typically flagged as an outlier and removed from the ensemble prior to calculation of the ensemble ET value. Crop type information available through the Data Explorer is not generated by OpenET and may not always accurately reflect the current crop type. Crop type information is provided to assist with interpretation of ET values. Outside of California, all crop type information is derived from the USDA Cropland Data Layer. Crop type information for California for 2016 and 2018 is based on the CA Department of Water Resources (DWR) Land Cover database developed by LandIQ. Data for annual crops in California for all other years are from the USDA Cropland Data Layer.</p>