Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

World first in satellite-based monitoring of large lake areas

15.04.2002


Algal blooms in the Southern Baltic Sea 23.7.2001


Satellite sensors operating in the visible wavelength region are now in use for the monitoring of oceanic waters.

For the first time ever, Finnish scientists have demonstrated the practical usability of satellite data for the simultaneous monitoring of water quality in large lake and coastal regions. The project was carried out by the Laboratory of Space Technology of the Helsinki University of Technology in cooperation with the Finnish Environment Institute.

The attached figures show examples of water turbidity retrieval results obtained for Finnish lake and coastal regions by applying Nasa’s MODIS spectrometer data, with more to come from the ESA Envisat MERIS-spectrometer. These sensors with nearly global daily coverage employ visible wavelength channels of observation with spectral characteristics suited for water quality monitoring of turbid lakes and coastal regions. Turbidity is one of the essential water quality indicators as it describes, in practise, the integrated amount of algae biomass and suspended matter.



The possibility to cover a large area in a single sweep is the most important improvement that can be obtained from using satellite data. The method also enables the detection of rapidly evolving phenomena such as algae blooms or oil spills and makes it possible to obtain information on regions which would normally not be monitored at all.

Conventional discrete water quality sampling or the collection transect data with ship-borne observation systems never give a complete areal vision.

These improvements are important aspects in boreal regions where the number of lakes is large and the quality of lake water is highly variable and sensitive to external pollution and climate change. In Finland, for example, the total number of lakes exceeding the minimum area of 0.01 km2 (1 ha) is about 60,000. MODIS data enables the monitoring of about 50 percent of the total Finnish lake area (16,000 km2).

Monitoring the status of the Baltic Sea is another promising application for satellite sensors. The analysis of the data from MODIS and SeaWiFS spectrometers has shown that satellite observations are useful for the mapping of turbidity, chlorophyll concentration (algae biomass) and algae blooms. Particularly interesting results have been obtained for the Gulf of Finland using MODIS observations. The MODIS data-based turbidity maps have demonstrated the strong influence of the St. Petersburg region on the overall water quality in the Gulf of Finland.

A good spatial resolution is required to monitor Baltic coastal regions and boreal forest/sub-arctic zone with fragmented water bodies, lakes and coastal zones comprising a small-scaled labyrinth of water and land areas. The spatial resolution of MODIS and MERIS is adequate even for the monitoring of the lakes of boreal forest zone: at its best 250 m and 300 m, respectively.

Jari Kirsilä | alphagalileo
Further information:
http://www.space.hut.fi

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

The Maturation Pattern of the Hippocampus Drives Human Memory Deve

23.07.2018 | Science Education

FAU researchers identify Parkinson's disease as a possible autoimmune disease

23.07.2018 | Health and Medicine

O2 stable hydrogenases for applications

23.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>