The NASA Earth Observatory's Image of the Day feature shows the highlights in satellite technology.

On January 26, 2010, they featured a map of water use on Idaho’s Snake River Plain.

The image shows evapotranspiration from vegetation on the Snake River Plain in south-central Idaho, with fields of irrigated crops. Fallow and recently harvested fields are coloured lighter blue than the fully irrigated crops, because they consume less water. The surrounding natural scrubland uses far less water as rainfall is only limited.

The image was created with a model based on SEBAL. The model combines Landsat measurements of surface temperature and vegetation with weather data to estimate how much water is entering the atmosphere through evapotranspiration.  Currently the model is used by the Idaho Department of Water Resources to monitor water use at a relatively inexpensive way.

To read more about the technology, please also visit the item “Water Watchers” on the Earth Observatory website.