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 Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>