Assessing Water Quality From Space

By Sara Jerome,
@sarmje

One of the clearest portraits of water quality on Earth may come from outer space.

A team of researchers from around the world recently demonstrated that it is possible to assess water pollution levels from satellites, according to a report from the University of Leicester. The findings were published by the academic publishing company Elsevier BV.

"The research team from the University of Leicester, the Hungarian Academy of Science and industrial partners has used the MEdium Resolution Imaging Spectrometer (MERIS) instrument hosted on the satellite ENVISAT to measure pollution levels in lakes on Earth through 'Superhero vision', allowing it to see wavelengths invisible to the human eye, which only sees red, green and blue light," the report said.

This approach had already been used for oceans, but it is not readily available for lakes, including shallow ones.

The researchers focused on Lake Balaton, which is Central Europe's largest lake and a popular tourist spot. They used satellite imaging to assess algae levels on the lake.

The lake's "very shallow depth means that Balaton is a unique system, as both a habitat and a recreational resource, but also in terms of its optical properties," the study said.

Professor Heiko Balzter, a co-author of the study, explained that, from the ground, it’s tough to get an accurate reading of the lake's water quality.

"When water quality samples are taken from a ship it is not only a logistic nightmare, but the data collection costs a lot of money and only provides point measurements, making the estimation on the whole lake level very speculative," he said, per the report.

"The frequent satellite data of MERIS adds a synoptic observation to the study of algal blooms and how they develop," he continued.

The study concluded that these imaging techniques could be useful in supporting public policy efforts around pollution reduction.

"The realization of operational products for lakes will substantially support the requirements of the ongoing basis towards meeting European Commission Water Framework Directive for spatially cohesive water quality monitoring, including the concentration of phytoplankton biomass," the study said.

Image credit: "Earth Horizon," © 2011 U.S. DonkeyHotey license: http://creativecommons.org/licenses/by/2.0/deed.en