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Water Quality Information, SISCAL

European scientists are making a wealth of satellite-derived data on water quality easily accessible.

Users can map specific areas in near real-time, and use the results to get the “bigger picture” of water quality that is easily missed by spot sampling programmes.

A scientist leans over the edge of her boat and hoists in the last sampling jar. She closes the lid and packs it into a crate with all the others. Later, the laboratory will declare the area clear of contamination, but just a kilometre away, an undetected toxic algal bloom is spreading.
“Spot sampling is most accurate for monitoring water quality, but it can miss the big picture,” says Dr Frank Fell, director of the small German IT company Informus. “Samples from a river mouth do not tell you about the quality of water a kilometre out to sea, nor ten kilometres along the coast. That’s when you need satellite data, which can image water quality over an entire area.”
Fortunately, even though satellites cost millions to build and send into space, it is relatively cheap to tap into their resources. The data from several earth observation and weather satellites are available online for public use.

Tapping into the data

“Back in 2000, we realised that useful earth observation data was available and could really help environmental agencies to monitor water quality,” Dr Fell says. “But it was technically difficult to get hold of the information, which came from different space agencies in different formats. So we formed a research project to develop a simple online tool that non-experts could use to access archived or near real-time satellite data for specific geographical areas.”

The SISCAL service is the result of four years of EU-funded collaboration between European universities, environmental research institutes and public agencies responsible for water quality in Denmark, Norway, Germany and Israel. It combines internet, data processing and storage technologies with geographic information systems (GIS).

SISCAL’s customers can use the system to access and visualise water quality information for a specific geographic location. Water quality indicators including sea surface temperature, chlorophyll-a concentration and sediment concentrations.
An important aspect of SISCAL service which differentiates it from similar products is its customisation: users can incorporate their local knowledge of the eco-system into the data processing and analysis.

“The data coming from the space agencies is processed using global algorithms,” explains Dr Fell, “but these are not always appropriate for smaller, localised geographic areas. We tailor SISCAL for each user and incorporate local algorithms that make the satellite data more accurate for each area under observation. SISCAL also renders the satellite data and combines it with the user’s own data archive to make it available for GIS software.”

Big clients

SISCAL currently has three clients: two are in Israel (the Ministry of the Environment and the Israel Water Commission) and one in Australia (a private desalination facility). These clients are using the tool to complement their existing in situ sampling networks. For example, flooding on the Nile may push large plumes of sediment along the Levantine coast, but the satellite images provide advanced warning, so that Israel’s coastal desalination plants can protect their filters from clogging.

SISCAL is also providing Israel’s electricity companies with a much better idea of marine temperatures so that they can adjust their generating output according to the temperature of the sea, which is used as cooling water.

The Water Commission is using SISCAL to monitor water quality (especially the duration and extent of algal blooms), particularly on Lake Kinneret. The tool helps to optimise the positioning and procedures for the in situ monitoring systems.

“We developed some local algorithms for the Water Commission,” says Dr Fell. “The operational product from the satellites was out of range when applied to just the lake, but we derived some simple algorithms that made it possible to apply earth observation to this lake.”

But why so much interest from clients outside of Europe?

Dr Fell explains that SISCAL is ideal for the export market.

“European environmental agencies have invested huge amounts on vast, effective in situ monitoring networks to comply with legislation, such as the Water Framework Directive. They are meeting their legal obligations and mostly do not have the resources to purchase the additional benefits of SISCAL. But outside Europe, where in situ monitoring is much less extensive, people are willing to invest. SISCAL perfectly complements and enhances their spot sampling networks. In fact, earth observation may even be the only reliable source of information available.”

Dr Fell is confident that more SISCAL clients, perhaps some from within Europe, will come on board as the benefits of earth observation in this field become more recognised.

“We have an operational system that has been running smoothly for four years,” he says. “SISCAL is providing users with a customised system and near real-time satellite data. Earth observation of the marine eco-system is feasible and fruitful.”

Source: ICT Results