The associated geotiff rasters represents the total actual evapotranspiration (ETa) from June through September for the years 2004, 2006, 2008-2010, and 2013-2016 for the entire Klamath Basin in southern Oregon. The ETa was created using Landsat imagery and the Operational Simplified Surface Energy Balance (SSEBop) model to estimate actual ET and the Python scripts to complete that process is also provided. Additionally, the June-September average (mean) ETa for the "base years" of 2004, 2006, 2008-2010 and ETa Anomaly (deviation from the base years average mean) for each year between 2013-2016 is provided. Text files of SSEBop daily actual ET along with actual ET from Ameriflux eddy co-variance flux tower sites is also provided including an R code to generate comparison charts.

Historical (1984-2014) Landsat-based ET maps were generated for Palo Verde Irrigation District (PVID) and eight other sub-basins in parts of Middle and Lower Central Valley, California. A total of 3,396 Landsat images were processed using the Operational Simplified Surface Energy balance (SSEBop) model that integrates weather and remotely sensed images to estimate monthly and annual ET within the study areas over the 31 years. Model output evaluation and validation using gridded-flux data and water balance ET approaches indicated relatively strong association between SSEBop ET and validation datasets. Historical trend analysis of seven agro-hydrologic variables were done using the Seasonal Mann-Kendall test.

Historical (1984-2014) Landsat-based ET maps were generated for Palo Verde Irrigation District (PVID) and eight other sub-basins in parts of Middle and Lower Central Valley, California. A total of 3,396 Landsat images were processed using the Operational Simplified Surface Energy balance (SSEBop) model that integrates weather and remotely sensed images to estimate monthly and annual ET within the study areas over the 31 years. Model output evaluation and validation using gridded-flux data and water balance ET approaches indicated relatively strong association between SSEBop ET and validation datasets. Historical trend analysis of seven agro-hydrologic variables were done using the Seasonal Mann-Kendall test.

This data release provides a monthly irrigation water use reanalysis for the period 2000-20 for all U.S. Geological Survey (USGS) Watershed Boundary Dataset of Subwatersheds (Hydrologic Unit Code 12 [HUC12]) in the conterminous United States (CONUS). Results include reference evapotranspiration (ETo), actual evapotranspiration (ETa), irrigated areas, consumptive use, and effective precipitation for each HUC12. ETo and ETa were estimated using the operational Simplified Surface Energy Balance (SSEBop, Senay and others, 2013; Senay and others, 2020) model executed in the OpenET (Melton and others, 2021) web-based application implemented in Google Earth Engine. Results provided by OpenET/SSEBop were summarized to hydrologic response units (HRUs) in the National Hydrologic Model (NHM; Regan and others, 2019) to estimate consumptive use and effective precipitation on irrigated lands. Irrigated lands for the CONUS were provided by the Landsat-based Irrigation Dataset (LANID; Xie and others, 2019) for each year of the reanalysis period. Consumptive use estimates provided by the NHM were disaggregated to HUC12s using area weighted intersections with HRUs and the relative proportion of irrigated lands in each intersected area. These datasets are generated during the irrigation reanalysis workflow (irrigation_reanalysis.7zip). The files actet_openet.cbh, potet_openet.cbh, and dyn_ag_frac.param are created in step one of the workflow, which involves converting daily OpenET/SSEBop results into inputs for the NHM. All other files are produced by the NHM and are utilized for calculating irrigation consumptive use and effective precipitation.

This data release provides a monthly irrigation water use reanalysis for the period 2000-20 for all U.S. Geological Survey (USGS) Watershed Boundary Dataset of Subwatersheds (Hydrologic Unit Code 12 [HUC12]) in the conterminous United States (CONUS). Results include reference evapotranspiration (ETo), actual evapotranspiration (ETa), irrigated areas, consumptive use, and effective precipitation for each HUC12. ETo and ETa were estimated using the operational Simplified Surface Energy Balance (SSEBop, Senay and others, 2013; Senay and others, 2020) model executed in the OpenET (Melton and others, 2021) web-based application implemented in Google Earth Engine. Results provided by OpenET/SSEBop were summarized to hydrologic response units (HRUs) in the National Hydrologic Model (NHM; Regan and others, 2019) to estimate consumptive use and effective precipitation on irrigated lands. Irrigated lands for the CONUS were provided by the Landsat-based Irrigation Dataset (LANID; Xie and others, 2019) for each year of the reanalysis period. Consumptive use estimates provided by the NHM were disaggregated to HUC12s using area weighted intersections with HRUs and the relative proportion of irrigated lands in each intersected area. These datasets are generated during the irrigation reanalysis workflow (irrigation_reanalysis.7zip). The files actet_openet.cbh, potet_openet.cbh, and dyn_ag_frac.param are created in step one of the workflow, which involves converting daily OpenET/SSEBop results into inputs for the NHM. All other files are produced by the NHM and are utilized for calculating irrigation consumptive use and effective precipitation.

CONUS-wide actual ET (ETa) from Landsat thermal imagery-using the Operational Simplified Surface Energy Balance (SSEBop) model (version 4) in the Google Earth Engine (GEE) cloud computing platform. Over 150,000 Landsat satellite images were used to produce 10 years of annual ETa (2010-2019).

CONUS-wide actual ET (ETa) from Landsat thermal imagery-using the Operational Simplified Surface Energy Balance (SSEBop) model (version 4) in the Google Earth Engine (GEE) cloud computing platform. Over 150,000 Landsat satellite images were used to produce 10 years of annual ETa (2010-2019).

The evapotranspiration (ET) datasets were created under contract for this study by the University of Idaho. A high-resolution remote sensing technique known as Mapping Evapotranspiration at High Resolution and Internalized Calibration (METRIC) was used to create estimates of the spatial distribution of ET. The METRIC technique uses thermal infrared Landsat imagery to quantify actual evapotranspiration at a 30-meter resolution that can be related to individual irrigated fields. Because evaporation uses heat energy, ground surfaces with large ET rates are left cooler as a result of ET than ground surfaces that have less ET. As a consequence, irrigated fields appear in the Landsat images as cooler than nonirrigated fields. Products produced from this study include total seasonal and total monthly (April-October) actual evapotranspiration maps for 2013.

The evapotranspiration (ET) datasets were created under contract for this study by the University of Idaho. A high-resolution remote sensing technique known as Mapping Evapotranspiration at High Resolution and Internalized Calibration (METRIC) was used to create estimates of the spatial distribution of ET. The METRIC technique uses thermal infrared Landsat imagery to quantify actual evapotranspiration at a 30-meter resolution that can be related to individual irrigated fields. Because evaporation uses heat energy, ground surfaces with large ET rates are left cooler as a result of ET than ground surfaces that have less ET. As a consequence, irrigated fields appear in the Landsat images as cooler than nonirrigated fields. Products produced from this study include total seasonal and total monthly (April-October) actual evapotranspiration maps for 2013.

The evapotranspiration (ET) datasets were created under contract for this study by the University of Idaho. A high-resolution remote sensing technique known as Mapping Evapotranspiration at High Resolution and Internalized Calibration (METRIC) was used to create estimates of the spatial distribution of ET. The METRIC technique uses thermal infrared Landsat imagery to quantify actual evapotranspiration at a 30-meter resolution that can be related to individual irrigated fields. Because evaporation uses heat energy, ground surfaces with large ET rates are left cooler as a result of ET than ground surfaces that have less ET. As a consequence, irrigated fields appear in the Landsat images as cooler than nonirrigated fields. Products produced from this study include total seasonal and total monthly (April-October) actual evapotranspiration maps for 2013.