Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sediments cause problems for the world’s rivers and coasts

24.06.2005


Billions of tonnes of sediment are clogging up the world’s coastal zones, rivers and estuaries with devastating results to the environment, say scientists attending an international meeting organised by the Land-Ocean Interactions in the Coastal Zone (LOICZ) project, a global network of coastal and marine scientists.



Nutrient-laden mud, gravel and sand, pushed downstream by large rivers and estuaries, are changing the shape of coastlines, destroying aquatic life and even filling up parts of shallow continental shelves, they say.

Ironically, a seemingly opposite problem is also occurring in many regions. Damming of rivers is causing a loss of an estimated 1.4 billion tonnes of sediment that never make it to the coast. This results in a shortage of nutrient supply to the coast and severe erosion. An average of 1 dam higher than 15 m is built daily and large rivers are “managed” to extremes with almost no net run-off to the sea. These result in declines in fisheries and increased sediment-related risks for coastal cities.


Unfortunately the two forces do not cancel each other out since the primary impacts are local and regional rather than global.

The meeting will highlight future scenarios for coastal zones and how science is helping communities adapt to change and deal with catchment-to-coast issues.

As coastal mega cities and urban sprawl expand across all continents, estuaries, beaches and shallow seas are being consumed by polluted mud, gravel and silt at frightening rates, the scientists warn. Large cities are among the worst offenders. Of the world’s mega cities with populations over 10 million inhabitants, 14 are coastal.

Roughly 3.1 billion people – half of the world’s population – are estimated to live within 200 kilometres of a coast. In Latin America, the most urbanised of the developing regions, three-quarters of the population - 382 million – live within 200 kilometres of a seacoast.

While rivers are the main conduits of sediment transport and large dams are man-made reservoirs that reduce their delivery to the coast, it appears that climate change and incremental sea level rise will have an even more insidious and damaging affect over time. Coastal engineer Dr Boot, of the Department of Marine and Coastal Management at Delft in the Netherlands said widespread beach erosion is already occurring at a global scale. He estimates that 70% of the world’s sandy beaches are already eroding and increasing sea levels will only exacerbate the problem.

Using a new model called DIVA (Dynamic Interactive Vulnerability Assessment), developed by a multi-disciplinary team of researchers from Germany, United Kingdom and The Netherlands, Dr Boot said the model shows that, without adaptation, coastal retreat could be significant in nearly all regions of the world, with impacts such as land loss, urban inundation and damage to beach-based tourism.

The science meeting will also review how coastal development has led to the systematic overexploitation of near-shore fisheries; pollution from urban settlement, tourism and industrial development; poor estuarine water quality for ecosystem and public health; the rapid decline of waterways, mangrove forests and degradation of coastal ecosystems, such as seagrass beds and coral reefs.

But it’s not all “gloom and doom” says LOICZ Chairperson, Liana McManus from the University of Miami Rosenstiel School. “The meeting will present new tools to address these threats, and innovative approaches to show how societies contribute to coastal problems and what their options are to move current scenarios to more sustainable states,” she says.

“We need a coordinated global effort to overcome the many and complex changes occurring in the world’s coastal zones. LOICZ is about the integrated science of coasts and the people dependent on these systems. Along with our research partners, we strive to provide the science so people can make better informed decisions on how they can manage their coastal systems. To sustain these, all sectors of the community must be engaged”.

Don Alcock | alfa
Further information:
http://www.loicz.org/loicz_nl/loicz_nl_homepage.php

More articles from Ecology, The Environment and Conservation:

nachricht Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

nachricht Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München

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: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>