Daily evaporation rates were calculated at the open-water LZ40-platform in the interior of Lake Okeechobee, Florida, from December 1, 2012 through December 31, 2016 using five methods (Shoemaker et al., 2024); specifically, the Penman, Priestly-Taylor, Mass-Transfer, Simple, and Turc equations. Bowen-ratio energy-budget derived daily evaporation rates calculated from micro-meteorological data at the LZ40 site (Wacker, 2020) are considered a standard by which to evaluate the five alternative evaporation methods. Parameterization of each of method and comparison of evaporation using each of the five methods to the Bowen ratio estimates are published by Shoemaker and others (2024).

Daily measurements of evaporation using the Bowen ratio method were made at USGS station name LZ40 (USGS site number 265405080472100), a platform-based station constructed by the South Florida Water Management District (SFWMD) at the approximate center of Lake Okeechobee, Florida. Meteorological and environmental variables were measured every 30 seconds and averaged at 15-minute resolution, including: water temperature (surface and profile), air temperature, relative humidity, wind speed, and incoming/outgoing short and longwave radiation.

Daily measurements of evaporation using the Bowen ratio method were made at USGS station name LZ40 (USGS site number 265405080472100), a platform-based station constructed by the South Florida Water Management District (SFWMD) at the approximate center of Lake Okeechobee, Florida. Meteorological and environmental variables were measured every 30 seconds and averaged at 15-minute resolution, including: water temperature (surface and profile), air temperature, relative humidity, wind speed, and incoming/outgoing short and longwave radiation.

Daily measurements of evaporation using the Bowen ratio method were made at USGS station name LZ40 (USGS site number 265405080472100), a platform-based station constructed by the South Florida Water Management District (SFWMD) at the approximate center of Lake Okeechobee, Florida. Data collection began on November 15, 2012. Meteorological and environmental variables were measured every 30 seconds and averaged at 30-minute resolution until February 7, 2013 and 15-minute resolution thereafter to December 31, 2019, including: precipitation, air temperature, relative humidity, wind speed, incoming/outgoing solar radiation, and water temperature at various depths.

The data consists of daily evaporation measurements/estimates for the time period November 28, 2001 to December 16, 2019. These data are derived from Bowen ratio energy budget computations of actual evaporation based on meteorological and water temperature data at the USGS Reedy Lake evaporation station (USGS station number 282458081364800). This station is located near the center of a lake within the Lake Wales Ridge physiographic province at location 28 degrees 24 minutes 58 seconds North / 081 degrees 36 minutes 48 seconds West within Orange County, Florida. The black water (tannic) lake is crudely circular in shape (minimum and maximum diameters of 750 and 920 meters) and is largely surrounded by forests. The lake is landlocked aside from a possible overflow to the east at high stage. The lake is within sandy terrain composing the surficial aquifer and likely receives discharges of ground water from the aquifer.

The data consists of daily evaporation measurements/estimates for the time period November 28, 2001 to December 16, 2019. These data are derived from Bowen ratio energy budget computations of actual evaporation based on meteorological and water temperature data at the USGS Reedy Lake evaporation station (USGS station number 282458081364800). This station is located near the center of a lake within the Lake Wales Ridge physiographic province at location 28 degrees 24 minutes 58 seconds North / 081 degrees 36 minutes 48 seconds West within Orange County, Florida. The black water (tannic) lake is crudely circular in shape (minimum and maximum diameters of 750 and 920 meters) and is largely surrounded by forests. The lake is landlocked aside from a possible overflow to the east at high stage. The lake is within sandy terrain composing the surficial aquifer and likely receives discharges of ground water from the aquifer.

The dataset includes a table in comma delimited format of daily evapotranspiration (ET) from 6/15/2017 to 1/21/2020 from an ET station in wetlands along the western perimeter of Lake Okeechobee, near Clewiston, Florida. The dominant plant cover at the study site is sawgrass (Cladium jamaicense) with secondary amounts of cattails and open water surfaces such as canals for boat navigation. Sawgrass and cattail height generally varies from less than 1 to 2.4 meters. The depth of water in the wetland averages less than 1 meter above land surface but exceeds 1.5 meters when water levels are high in Lake Okeechobee. In contrast, water levels were less than 1 meter below land surface in the wetland from May to June of 2019. Evapotranspiration was estimated using eddy-covariance methods and missing records were gap-filled with the Priestley-Taylor (PT) equation (Priestley and Taylor, 1972) that was regressed against observed daily values of eddy-covariance ET. A constant value of 1.22374 was estimated by regression for the alpha coefficient in the PT equation to minimize residuals. Data processing methods were similar to methods outlined by Shoemaker and others (2011). Ancillary data includes net radiation, relative humidity, air temperature, and lake water temperature.

The dataset includes a table in comma delimited format of daily evapotranspiration (ET) from 6/15/2017 to 1/21/2020 from an ET station in wetlands along the western perimeter of Lake Okeechobee, near Clewiston, Florida. The dominant plant cover at the study site is sawgrass (Cladium jamaicense) with secondary amounts of cattails and open water surfaces such as canals for boat navigation. Sawgrass and cattail height generally varies from less than 1 to 2.4 meters. The depth of water in the wetland averages less than 1 meter above land surface but exceeds 1.5 meters when water levels are high in Lake Okeechobee. In contrast, water levels were less than 1 meter below land surface in the wetland from May to June of 2019. Evapotranspiration was estimated using eddy-covariance methods and missing records were gap-filled with the Priestley-Taylor (PT) equation (Priestley and Taylor, 1972) that was regressed against observed daily values of eddy-covariance ET. A constant value of 1.22374 was estimated by regression for the alpha coefficient in the PT equation to minimize residuals. Data processing methods were similar to methods outlined by Shoemaker and others (2011). Ancillary data includes net radiation, relative humidity, air temperature, and lake water temperature.

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.