Actual evapotranspiration (ETa) values estimated for specified areas including 1) total county areas; 2) potentially irrigated areas within each county; and 3) mapped extents of irrigated lands within each county provided by some states. These ETa estimates were provided to the USGS National Water Use Science Project by the USGS Earth Resources Observation and Science (EROS) Center (Gabriel Senay and MacKenzie Friedrichs, written communication, 2/20/2017) and are based on 1-square kilometer resolution 2015 Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data analyzed through the operational Simplified Surface Energy Balance (SSEBop) model using methods of Senay and others (2013). Reference: Senay, G.B., Bohms, S., Singh, R.K., Gowda, P.H., Velpuri, N.M., Alemu, H., and Verdin, J.P., 2013, Operational evapotranspiration mapping using remote sensing and weather datasets: A new parameterization for the SSEB approach; Journal of the American Water Resources Association, 49 (2013), pp. 577–591.

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.

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 dataset includes 1km resolution monthly timescale estimates of evapotranspiration (ET) for the 2000-2015 timespan. These new SSEBop-WB estimates were developed by combining a previously published long-term annual average evapotranspiration map based on water balance constraints with the SSEBop remote sensing ET product (see Associated Items). The combination aims to leverage the advantages of each approach in gaining both the temporal resolution of remote sensing data and the long-term magnitude constraints of ground-based data. This data release also includes other supporting data associated with the publication of these estimation methods in a concurrent journal article. Analyses in the journal article included comparisons between SSEBop ET, the MOD16 remote sensing ET product, and the new SSEBop-WB ET in a variety of settings against ET data from 119 flux towers across the U.S. Residuals between the remote sensing methods and the flux tower data were mapped spatially, and these maps are included in the data release as well. The methods are fully described in the forthcoming article accepted for publication in Remote Sensing as of November 2017; this dataset will be updated with its full citation when available. See also the metadata file for additional information, or contact the authors with questions.

This dataset includes 1km resolution monthly timescale estimates of evapotranspiration (ET) for the 2000-2015 timespan. These new SSEBop-WB estimates were developed by combining a previously published long-term annual average evapotranspiration map based on water balance constraints with the SSEBop remote sensing ET product (see Associated Items). The combination aims to leverage the advantages of each approach in gaining both the temporal resolution of remote sensing data and the long-term magnitude constraints of ground-based data. This data release also includes other supporting data associated with the publication of these estimation methods in a concurrent journal article. Analyses in the journal article included comparisons between SSEBop ET, the MOD16 remote sensing ET product, and the new SSEBop-WB ET in a variety of settings against ET data from 119 flux towers across the U.S. Residuals between the remote sensing methods and the flux tower data were mapped spatially, and these maps are included in the data release as well. The methods are fully described in the forthcoming article accepted for publication in Remote Sensing as of November 2017; this dataset will be updated with its full citation when available. See also the metadata file for additional information, or contact the authors with questions.

This U.S. Geological Survey data release presents monthly evaporation estimates from Lake Mead, Nevada and Arizona. Data are updated approximately annually. The spreadsheet includes five worksheets: (1) Read_Me worksheet contains information relevant to understanding the data contained in the rest of the worksheets. (2) Monthly_EC_Met worksheet includes data measured at a land-based station (USGS site identification number 360500114465601) using primarily eddy covariance measurement methods: uncorrected evaporation, latent- and sensible-heat fluxes, net radiation, air temperature, wind speed, and relative humidity. Values are monthly averages computed by averaging daily values except as noted. Monthly values are marked as estimated when a significant portion of daily values are estimated. (3) Monthly_Energy-Budget_Data worksheet includes computed data used to correct measured evaporation for energy balance. Computed data include monthly values for change in stored heat, net advection, turbulent flux, available energy, energy balance ratio, energy balance closure, and Bowen ratio. Change in stored heat was calculated based on methods in Earp and Moreo (2021). Net advection was calculated based on data estimated by the Bureau of Reclamation 24-Month Study (2022). Values are monthly averages or computed from monthly averages. (4) Annual_Energy_Balance worksheet includes annual averages of the Monthly_Energy_Balance data and the annual average values for energy-balance corrected sensible and latent heat fluxes. Values are annual averages or computed from annual averages. (5) Monthly_Evaporation_Estimates worksheet includes measured evaporation, corrected (most probable) evaporation, and energy balance ratio (EBR) adjusted evaporation, in feet. Values are monthly averages or computed from monthly averages. Data were processed according to methods described in Moreo and Swancar (2013) and Earp and Moreo (2021). References Cited: Bureau of Reclamation, Lower Colorado Region website: Operation Plan for Colorado River System Reservoirs (24-Month Study), accessed September 1, 2022 at https://www.usbr.gov/lc/region/g4000/24mo/index.html. Earp, K.J., and Moreo, M.T., 2021, Evaporation from Lake Mead and Lake Mohave, Nevada and Arizona, 2010–2019: U.S. Geological Survey Open-File Report 2021–1022, 36 p., https://doi.org/10.3133/ofr20211022. Moreo, M.T., and Swancar, A., 2013, Evaporation from Lake Mead, Nevada and Arizona, March 2010 through February 2012: U.S. Geological Survey Scientific Investigations Report 2013–5229, 40 p., http://dx.doi.org/10.3133/sir20135229.

This U.S. Geological Survey data release presents monthly evaporation estimates from Lake Mead, Nevada and Arizona. Data are updated approximately annually. The spreadsheet includes five worksheets: (1) Read_Me worksheet contains information relevant to understanding the data contained in the rest of the worksheets. (2) Monthly_EC_Met worksheet includes data measured at a land-based station (USGS site identification number 360500114465601) using primarily eddy covariance measurement methods: uncorrected evaporation, latent- and sensible-heat fluxes, net radiation, air temperature, wind speed, and relative humidity. Values are monthly averages computed by averaging daily values except as noted. Monthly values are marked as estimated when a significant portion of daily values are estimated. (3) Monthly_Energy-Budget_Data worksheet includes computed data used to correct measured evaporation for energy balance. Computed data include monthly values for change in stored heat, net advection, turbulent flux, available energy, energy balance ratio, energy balance closure, and Bowen ratio. Change in stored heat was calculated based on methods in Earp and Moreo (2021). Net advection was calculated based on data estimated by the Bureau of Reclamation 24-Month Study (2022). Values are monthly averages or computed from monthly averages. (4) Annual_Energy_Balance worksheet includes annual averages of the Monthly_Energy_Balance data and the annual average values for energy-balance corrected sensible and latent heat fluxes. Values are annual averages or computed from annual averages. (5) Monthly_Evaporation_Estimates worksheet includes measured evaporation, corrected (most probable) evaporation, and energy balance ratio (EBR) adjusted evaporation, in feet. Values are monthly averages or computed from monthly averages. Data were processed according to methods described in Moreo and Swancar (2013) and Earp and Moreo (2021). References Cited: Bureau of Reclamation, Lower Colorado Region website: Operation Plan for Colorado River System Reservoirs (24-Month Study), accessed September 1, 2022 at https://www.usbr.gov/lc/region/g4000/24mo/index.html. Earp, K.J., and Moreo, M.T., 2021, Evaporation from Lake Mead and Lake Mohave, Nevada and Arizona, 2010–2019: U.S. Geological Survey Open-File Report 2021–1022, 36 p., https://doi.org/10.3133/ofr20211022. Moreo, M.T., and Swancar, A., 2013, Evaporation from Lake Mead, Nevada and Arizona, March 2010 through February 2012: U.S. Geological Survey Scientific Investigations Report 2013–5229, 40 p., http://dx.doi.org/10.3133/sir20135229.

Actual evapotranspiration (AET) annual rates, from 2000 to 2017, for the Simplified Surface Energy Balance operational (SSEBop) method and from 2000 to 2016 for the land-cover based method, provided in shapefiles AET_SJR_Basin_Cells, are explained in the metadata file AET_SJR_Basins. The calculation of the annual average AET rates using a water-budget analysis (WBA) is explained in this metadata file referring to csv files for the eight basins in east-central and northeast Florida. A comparison of the average annual SSEBop AET rates and those derived from the WBA is then possible by using the average annual AET rates for each basin. The eight basins for which the WBA analysis was completed are: 1. St. Johns near Christmas basin (number 02232500), 2. Econlockhatchee River basin (number 02233484), 3. Wekiva River basin (number 02235000), 4. Eau Gallie River basin (number 02249007), 5. South Prong at St. Sebastian River basin (number 02251000), 6. Black Creek basin (number 02245500), 7. North Fork Black Creek basin (number 02246000), and 8. Deep Creek basin (number 02245260). The locations of these basins are shown in the shapefiles AET_SJR_Basin_Cells. Average annual rainfall (Rainfall), average annual net stream outflow (NetOutflow), average annual downward leakage from the surficial aquifer (Leakage) to the underlying hydrogeologic unit, net annual changes in storage calculated from measured water levels in surficial aquifer wells (Sy*dh/dt), and total annual return flow to land surface through irrigation and other water uses (Return_Flow) for all 8 basins were used to calculate the AET from the water-budget balance equation WB_AET = Rainfall – NetOutflow – Leakage -Sy*dh/dt + Return_Flow. Note that parameter Leakage is negative for discharge areas of the surficial aquifer. The results of the WBA method provided average annual AET rates for each basin, which can be compared with calculated annual averages from the SSEBop method for each entire basin, all rates in inches per year. The Return Flow estimates were obtained from the publication Marella, R.L., 2014, Water withdrawals, use, and trends in Florida, 2010: U.S. Geological Survey Scientific Investigations Report 2014-5088, 59 p., http://dx.doi.org/10.3133/sir20145088.

Actual evapotranspiration (AET) annual rates, from 2000 to 2017, for the Simplified Surface Energy Balance operational (SSEBop) method and from 2000 to 2016 for the land-cover based method, provided in shapefiles AET_SJR_Basin_Cells, are explained in the metadata file AET_SJR_Basins. The calculation of the annual average AET rates using a water-budget analysis (WBA) is explained in this metadata file referring to csv files for the eight basins in east-central and northeast Florida. A comparison of the average annual SSEBop AET rates and those derived from the WBA is then possible by using the average annual AET rates for each basin. The eight basins for which the WBA analysis was completed are: 1. St. Johns near Christmas basin (number 02232500), 2. Econlockhatchee River basin (number 02233484), 3. Wekiva River basin (number 02235000), 4. Eau Gallie River basin (number 02249007), 5. South Prong at St. Sebastian River basin (number 02251000), 6. Black Creek basin (number 02245500), 7. North Fork Black Creek basin (number 02246000), and 8. Deep Creek basin (number 02245260). The locations of these basins are shown in the shapefiles AET_SJR_Basin_Cells. Average annual rainfall (Rainfall), average annual net stream outflow (NetOutflow), average annual downward leakage from the surficial aquifer (Leakage) to the underlying hydrogeologic unit, net annual changes in storage calculated from measured water levels in surficial aquifer wells (Sy*dh/dt), and total annual return flow to land surface through irrigation and other water uses (Return_Flow) for all 8 basins were used to calculate the AET from the water-budget balance equation WB_AET = Rainfall – NetOutflow – Leakage -Sy*dh/dt + Return_Flow. Note that parameter Leakage is negative for discharge areas of the surficial aquifer. The results of the WBA method provided average annual AET rates for each basin, which can be compared with calculated annual averages from the SSEBop method for each entire basin, all rates in inches per year. The Return Flow estimates were obtained from the publication Marella, R.L., 2014, Water withdrawals, use, and trends in Florida, 2010: U.S. Geological Survey Scientific Investigations Report 2014-5088, 59 p., http://dx.doi.org/10.3133/sir20145088.