The constant monitoring of surface water quality can be challenging particularly if the water body extension is large and if the assessment is based on in-situ measurements. In this case the information of several sample gauges has to be combined and an area-wide estimation has to be made for instance by geostatistical methods. Remote sensing presents a valueable alternative to easily and regularly monitor large water surfaces at a modest time and cost expenditure.
The problem of bad water quality
Algae blooms are the most obvious sign of a bad water quality threatening drinking water, aquacultural farms and the public welfare. They are a very clear warning to react and stop harmful impacts into a water body. However, a significant bloom was recently forecasted for Lake Erie: NOAA predicts that this year’s blooms will be “among the most severe in recent years” and will peak in September (NOAA-News).
Monitoring water surface quality of oceans
A company that is specialized in monitoring water surfaces and water depth from space is EOMAP, based in Munich, Germany. So far the activity concentrated on Asian waters (great Barrier Reef, South China Sea, Red Sea, etc.), where EOMAP has been producing water quality maps, satellite-based bachimetry products, habitat and seafloor classifications as well as terrestrial monitoring. Many of the sites of work concern ecologically vulnerable areas such as coral reefs or mangroves.
From salty to sweet waters
Besides that, EOMAP also tracks the quality of lake surfaces. In this regard the company has recently developed an algae bloom monitoring program for the Great Lakes region. The bloom is now tracked daily and provides free online access through http://eoapp-us.eomap.com/.
EOMAP also tracks the vast number of smaller lakes and coastal waters globally using its multi-satellite monitoring system and displays this data on the eoApp web application. Aside from single, daily products, the application also provides spatially and temporally aggregated data: daily means (D’mean) and moving, weekly means (M’mean).
The eoapp monitoring system allows for tracking blue algae blooms and relevant water quality parameters such as chlorophyll and turbidity. Various US and European satellite sensors are imbedded into this first globally harmonized monitoring system, supporting daily monitoring at continental scales, historical reviews up to 30 years back in time and highest spatial resolutions for ponds, small lakes and rivers. Matt Bergin, Vice President of business Development at EOMAP states that ‘EOMAP supports European and US research initiatives to understand and forecast harmful algae blooms. The heavy bloom in 2015 was already well detected and well accessible through eoApp. The algorithm developed by EOMAP detects blue algae containing phycocyanin pigments. It is imbedded into the proprietary, state-of-the-art satellite data processors of EOMAP, which already are installed in several satellite receiving and archiving centers to support the most cost efficient and fast production.’