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 Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>