Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Floods forecast for Bangladesh

31.10.2001


Better flood forecasting could save lives in Bangladesh.
© AP/Abu Taher Khokon


With a weather monitoring network a new model could predict coastal floods in Bangladesh.

A new model should help forecast the massive floods to which the northern coast of Bangladesh is prone1. In principle, the model can predict the heights and arrival times of the huge waves that cyclones cause, and so could improve the planning of sea defences.

The effectiveness of the model will depend on the availability of accurate, timely and detailed meteorological data, cautions Bangladeshi scientist Junaid Amin As-Salek. He has spent six years in Japan with Takashi Yasuda of Gifu University developing the mathematical picture of the interactions between Bangladesh’s ocean, atmosphere and shoreline.

Gathering input data remains a formidable challenge. The technology for a weather-monitoring network exists, says As-Salek, who is now at the Great Lakes Environmental Research Laboratory in Michigan, USA. But a shortage of funding hampers its use in Bangladesh.

Bangladesh’s coast is in constant danger of devastating floods. Tropical hurricanes in the Indian Ocean move towards the coast, pushing a wall of water ahead of them. This creates a great wave called a storm surge, which can reach 12 meters high. In 1970, a five-metre wave flooded a million acres of rice fields, killing at least 200,000 people. More than 100,000 further lives were lost this way in 1991.

The country is densely populated and lacks the resources to erect defences or carry out evacuations. Also, the land is so low that even flood waves a couple of metres high can have terrible consequences.

Making waves

A coastal wave can have different effects at different times and places, making flooding hard to predict. As-Salek and Yasuda focused on the estuary of the Meghna River in the north of the Bay of Bengal - the region generally hit hardest by storm surges.

Their model provides a framework for predicting specific floods. It takes into account how coastal winds, the shape of the estuary, and the ebb and flow of the local tides affect a storm surge. A surge that coincides with a high tide, for example, is much more destructive. The estuary can also have a funnelling effect that accentuates flooding, As-Salek says.

The model could also help in planning permanent sea defences. At present, defences in Bangladesh are "very scattered and inadequate", says As-Salek who feels they were not based on scientific predictions.

Coastal engineering relies on estimates of the ’design cyclone’: the hypothetical hurricane that generates the flood wave with the largest water volume at a particular point. As-Salek hopes his model will help make these calculations, putting sea defences on a rational footing. Whether sufficient resources will be available to implement such planning is another matter.

References

  1. As-Salek, J. A. & Yasuda, T. Tide-surge interaction in the Meghna estuary: most severe conditions. Journal of Physical Oceanography, 31, 3059 - 3072, (2001).

PHILIP BALL | Nature News Service
Further information:
http://www.nature.com/nsu/011101/011101-9.html
http://www.nature.com/nsu/

More articles from Earth Sciences:

nachricht Fossil coral reefs show sea level rose in bursts during last warming
19.10.2017 | Rice University

nachricht NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>