Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Finger on the pulse of wetlands

25.06.2012
Many wetlands are difficult to observe over a long period. The reason for this is that the volume of water they channel varies all the time. Scientists from the University of Würzburg are now proposing a new method that allows wetland dynamics to be measured for the first time.
Wetlands like the Okavango Delta in southern Africa play an important role ecologically and economically. Not only do they provide a habitat for numerous species of animals and plants, they also have benefits for people. Often they are the only major water reservoir in an otherwise dry landscape. They also attract tourists and as such contribute to the livelihoods of local inhabitants.

Recording changes in wetlands

What impact will climate change have on such wetlands in Africa? It is predicted that this continent will become hotter and drier as a result of global changes. This might make the wetlands even more important in their role as water stores. But it might also completely dry them out.

“We need to be able to take the ‘pulse’ of the wetlands continuously so that we can observe changes and introduce any necessary countermeasures,” says Dr. Tobias Landmann from the University of Würzburg. This geographer, with his colleagues Christian Hüttich, Matthias Schramm, and Stefan Dech, has now made it possible to do this for the very first time. The journal “Remote Sensing Letters” presents the scientists’ method in its latest issue.

Finger on the pulse of the Linyanti Wetlands

The researchers chose the Linyanti Wetlands as their study object. This area is roughly 40 by 60 kilometers in size and lies in the east of Namibia on the border with Botswana, right in the middle of the dry savannah. It is fed by the Kwando River, which flows into a large delta in the Linyanti region, creating a considerable landscape of rivers and lakes.

How can we take the “pulse” of the Linyanti region continuously? Landmann and his colleagues have succeeded in doing this using image data from the NASA satellite MODIS. The satellite supplied high-resolution images of these African wetlands on an almost daily basis between 2001 and 2010. They clearly show the degree of flooding and the vitality of the vegetation, which are precisely the factors that interested the researchers since they wanted to know the following: how moist and green was Linyanti during this period, how did this fluctuate over the course of a year, and how did this vary from one year to another?

The Würzburg scientists took the satellite data and applied the so-called vector method to calculate the intensity and direction of the changes. This revealed that in some years the Linyanti region was drier, while in others it was more moist again. But, on the whole, the region became considerably more moist from 2001 to 2010.

“However, this does not allow any reliable statement regarding climate change because the time frame of just ten years is much too short,” says Landmann. This would require considerably longer time series. Such long-term measurements can now be undertaken for the earth’s wetlands for the first time – thanks to the wealth of satellite data available and thanks to the new method from Würzburg.

“MODIS based change vector analysis for assessing wetland dynamics in Southern Africa”, T. Landmann, M. Schramm, C. Huettich, and S. Dech, Remote Sensing Letters, published online 20 June 2012, DOI: 10.1080/2150704X.2012.699201

Contact

Dr. Tobias Landmann, Department of Remote Sensing, Institute of Geography and Geology at the University of Würzburg, T +49 (0)931 31-81869, tobias.landmann@uni-wuerzburg.de

Robert Emmerich | Uni Würzburg
Further information:
http://www.uni-wuerzburg.de

Further reports about: African public sector Linyanti Remote Wetlands global change satellite data

More articles from Earth Sciences:

nachricht NASA sees quick development of Hurricane Dora
27.06.2017 | NASA/Goddard Space Flight Center

nachricht Collapse of the European ice sheet caused chaos
27.06.2017 | CAGE - Center for Arctic Gas Hydrate, Climate and Environment

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>