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.
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.
Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute
How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Health and Medicine
13.12.2017 | Physics and Astronomy
13.12.2017 | Life Sciences