Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Space technology investigates large-scale changes to Africa's climate

06.03.2015

University of Leicester researchers map climate and human impacts on Africa's land resources using satellite mapping technology

An international research team led by the University of Leicester has mapped the entire African continent south of the Sahara for geographical changes - and has discovered that many areas receive drastically different amounts of rainfall today compared to just ten years ago.


This figure (2) shows a trend in vegetation greenness over 10 years. Green = greener conditions, red = less green conditions.

Credit

Image credit: Hoscilo, A., Balzter H., Bartholomé, E., Boschetti, M., Brivio, P.A., Brink, A., Clerici, M. and Pekel, J.-F. (2015): A conceptual model for assessing rainfall and vegetation trends in Sub-Saharan Africa from satellite data. International Journal of Climatology. doi: 10.1002/joc.4231.

The study, which investigated the rainfall and greenness of plants in African regions using satellite mapping technology, suggests that areas such as the Congo, Nigeria and Madagascar now receive far less rainfall than they did a decade ago, while other locations such as the Sahel zone have become far greener through increased rainfall.

Together with the Joint Research Centre of the European Commission, the Institute of Electromagnetic Sensing of Environment of the National Research Council of Italy, and the Polish Institute of Geodesy and Cartography, the study analysed 10 years of satellite data.

Professor Heiko Balzter, Director of the Centre for Landscape and Climate Research at the University of Leicester and co-author of the study, said: "We looked at the satellite data and discovered a number of surprising hotspots of change. Some parts of the Congo, Nigeria and Madagascar appear to receive much less rainfall now compared to 10 years ago. This is an issue even in the wet tropics of the Congo, where low rainfall means restrictions to ship movements on the rivers there, which are the main transport routes in the dense jungle.

"Large parts of the Sahel zone, which suffered from intense famine in the past, has greened up over the past decade, probably because of wetter weather. We know that rainfall in this region depends highly on the African monsoon. The weather systems can change a lot on the time-scales of tens of years. This means that our maps cannot be regarded as maps of long-term climate change impacts. They merely reflect climatic impacts over the past ten years. We know that this period is too short to relate it to the global warming debate.

"Future satellite observations will allow us to extend the time-series and observe large-scale changes in Africa."

Regions where more rainfall led to greener plants were mapped in West Africa, Central African Republic, West Cameroon and north-eastern part of South Africa. Areas of climatic vegetation degradation were located in Southern Madagascar, Nigeria, Kenya and the Garden Route region of South Africa.

Meteorological stations in Africa are far and between. Satellites can fill in the gaps in weather observations. The researchers used a rain dataset that is produced by the National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Centre and combined the best qualities of local rain gauge stations with the satellite data. The system is used by the US for a famine early warning system.

The findings highlight areas where climatic changes are the likely cause of greener or browner vegetation. More rain can lead to a 'greening up' of large regions, as was the case in the West African Sahel zone. If rains become scarcer, in dry areas the plants cannot 'green up' as much. This effect is large enough to be observed from satellite.

The new concept developed by the research team interprets satellite observations of rainfall and vegetation greenness at the same time. If the plants lost some of their greenness over time, then the researchers checked for climatic changes, meaning reduced rainfall. If reduced rains coincide with browner plants, the chances are that the climatic change causes the changes in the plants.

If there was more rain and the plants greened up over the ten years of data, the researchers think that there was a positive impact of climatic change on the plants. However, in areas where the weather got wetter but plants were browning, non-climatic factors are likely behind the change. Such factors can be human land use change, agricultural expansion, overgrazing or ecological disturbances.

With over 30 million km2 in size, Africa is a vast continent with over 200 times the area of England. Many countries are plagued by armed conflicts, water scarcity, diseases such as Ebola and HIV, slow economic development and high dependence on natural resources. Africa's vegetation plays a vital role in securing livelihoods and providing a basis of living for local communities.

Dr Agata Hoscilo, the postdoctoral researcher responsible for producing the satellite maps, added: "The results have shown that spatial patterns of different change processes can be detected in specific regions of Africa, which are generally consistent with independently reported literature on longer-term trends, El Ni?o effects and decadal-scale climate oscillations.

"This study confirms that most of the vegetation in sub-Saharan Africa depends on rainfall variability, particularly in the semi-arid and arid environments; however, there are areas where degradation of vegetation condition is driven by other anthropogenic or natural factors. The concept proved to be less reliable in the wet tropics. Use of coarse resolution satellite data can be a valuable source of information leading to better understanding of the drivers of change."

###

The study 'A conceptual model for assessing rainfall and vegetation trends in sub-Saharan Africa from satellite data' is published in the top-rated International Journal of Climatology, and is already available online. It is open access, free of charge. The journal has an Impact Factor of 3.4 and features in the top 20 journals in Meteorology & Atmospheric Sciences (ISI Journal Citation Reports © Ranking: 2013: 17/76).

The research was supported by the EU-FP7 funded Geoland-2 project.

Heiko Balzter | EurekAlert!

More articles from Earth Sciences:

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>