Evapotranspiration and Water Use Mapping
Water is one of our most valuable natural resources and understanding how it’s used is essential for managing it wisely. Scientists at the USGS Earth Resources Observation and Science (EROS) Center use satellite data to estimate how much water is lost from the land through evapotranspiration (ET)—the combined effect of evaporation from soil and water surfaces and transpiration from plants.
These ET estimates are generated using tested models developed at EROS, which combine remote sensing and weather data to provide detailed, reliable maps of water use across the United States. This information helps farmers, land managers, and policymakers make informed decisions about irrigation, drought response, and long-term water planning. Updated regularly, these tools support monitoring of seasonal patterns and long-term trends, helping identify areas of concern and guiding sustainable water management across farms, forests, and public lands.
Available Models
SSEBop model
The Operational Simplified Surface Energy Balance (SSEBop) model developed at EROS estimates water use by plants in irrigated fields using thermal data from Landsat’s Operational Land Imager (OLI) and the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA’s Terra satellite.
SSEBop combines rates of evaporation from the soil and transpiration from plants to return evapotranspiration (ET) readings that can help water managers decide how much water is needed throughout the growing season.
The model supports various aspects of the USGS Water Use Mission Area, including the National Water Use Science Project and the National Water Census, which releases a trove of water use information every five years.
EROS produces actual ET maps that depict monthly, seasonal cumulative, end of season and yearly anomalies for the conterminous United States, which are color-coded to depict rates above or below the median.
The maps are useful in determining irrigation needs, but also instructive of water use in different environment
The maps, data, product descriptions and helpful links are located online at the SSEBop website.
Download a poster
Evapotranspiration and Water Use poster
Eyes on Earth Episode 17 - Evapotranspiration
It’s easy enough to measure rainfall, and nearly as easy to measure streamflow. Calculating the efficiency of water use through the metric of evapotranspiration (ET) – evaporation off the Earth’s surface and transpiration from the leaves of plants – is a far trickier proposal. In this episode of Eyes on Earth, we hear how scientists use satellites like Landsat to measure ET, and how those...
Remote sensing of evapotranspiration for operational drought monitoring using principles of water and energy balance Remote sensing of evapotranspiration for operational drought monitoring using principles of water and energy balance
Enhancing the Simplified Surface Energy Balance (SSEB) Approach for Estimating Landscape ET: Validation with the METRIC model Enhancing the Simplified Surface Energy Balance (SSEB) Approach for Estimating Landscape ET: Validation with the METRIC model
Developing an operational rangeland water requirement satisfaction index Developing an operational rangeland water requirement satisfaction index
Estimating basin scale evapotranspiration (ET) by water balance and remote sensing methods Estimating basin scale evapotranspiration (ET) by water balance and remote sensing methods
Estimating actual evapotranspiration from irrigated fields using a simplified surface energy balance approach Estimating actual evapotranspiration from irrigated fields using a simplified surface energy balance approach
Lysimetric Evaluation of Simplified Surface Energy Balance Approach in the Texas High Plains Lysimetric Evaluation of Simplified Surface Energy Balance Approach in the Texas High Plains
Simplified Surface Energy Balance (SSEB) approach for estimating actual ET: An evaluation with lysimeter data Simplified Surface Energy Balance (SSEB) approach for estimating actual ET: An evaluation with lysimeter data
Modeling landscape evapotranspiration by integrating land surface phenology and a water balance algorithm Modeling landscape evapotranspiration by integrating land surface phenology and a water balance algorithm
Global daily reference evapotranspiration modeling and evaluation Global daily reference evapotranspiration modeling and evaluation
Remote sensing sensors and applications in environmental resources mapping and modeling Remote sensing sensors and applications in environmental resources mapping and modeling
A coupled remote sensing and simplified surface energy balance approach to estimate actual evapotranspiration from irrigated fields A coupled remote sensing and simplified surface energy balance approach to estimate actual evapotranspiration from irrigated fields
Developing index maps of water-harvest potential in Africa Developing index maps of water-harvest potential in Africa
USGS EROS User Services
Earth Resources Observation and Science (EROS) Center
Water is one of our most valuable natural resources and understanding how it’s used is essential for managing it wisely. Scientists at the USGS Earth Resources Observation and Science (EROS) Center use satellite data to estimate how much water is lost from the land through evapotranspiration (ET)—the combined effect of evaporation from soil and water surfaces and transpiration from plants.
These ET estimates are generated using tested models developed at EROS, which combine remote sensing and weather data to provide detailed, reliable maps of water use across the United States. This information helps farmers, land managers, and policymakers make informed decisions about irrigation, drought response, and long-term water planning. Updated regularly, these tools support monitoring of seasonal patterns and long-term trends, helping identify areas of concern and guiding sustainable water management across farms, forests, and public lands.
Available Models
SSEBop model
The Operational Simplified Surface Energy Balance (SSEBop) model developed at EROS estimates water use by plants in irrigated fields using thermal data from Landsat’s Operational Land Imager (OLI) and the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA’s Terra satellite.
SSEBop combines rates of evaporation from the soil and transpiration from plants to return evapotranspiration (ET) readings that can help water managers decide how much water is needed throughout the growing season.
The model supports various aspects of the USGS Water Use Mission Area, including the National Water Use Science Project and the National Water Census, which releases a trove of water use information every five years.
EROS produces actual ET maps that depict monthly, seasonal cumulative, end of season and yearly anomalies for the conterminous United States, which are color-coded to depict rates above or below the median.
The maps are useful in determining irrigation needs, but also instructive of water use in different environment
The maps, data, product descriptions and helpful links are located online at the SSEBop website.
Download a poster
Evapotranspiration and Water Use poster
Eyes on Earth Episode 17 - Evapotranspiration
It’s easy enough to measure rainfall, and nearly as easy to measure streamflow. Calculating the efficiency of water use through the metric of evapotranspiration (ET) – evaporation off the Earth’s surface and transpiration from the leaves of plants – is a far trickier proposal. In this episode of Eyes on Earth, we hear how scientists use satellites like Landsat to measure ET, and how those...