Researchers have developed a novel statistical model for prediction of floods and its duration. It also accurately determines the timescale of flooding. “It is possible to predict the duration of floods by coupling atmospheric dynamics and land surface conditions in the watershed,” said study researcher Nasser Najibi from the City College of New York.
For the study published in the journal Nature Research, researchers analysed data from the Missouri river basin from the last 50 years to develop the Bayesian network statistical model.
The research team found that long duration floods first require high flow conditions in rivers created by recurrent high-intensity rainfall events, which is then followed by a large stable long-lived low-pressure system — a storm cell. These conditions may then result in large-scale devastating floods.
In shorter duration, however, this land-atmospheric coupling is negligible thus explaining why not all storms result in widespread flooding.
The researchers said that with the help of this statistical model, potential risk imposed by longer duration floods on critical infrastructure systems such as flood control dams, bridges and power plants can be mitigated. It is also possible to predict how long the duration of flooding and inundation will be, they said. (IANS)
About 400 million are likely to be affected by coastal flooding by the end of the century if Greenland ice melt continues at its current rate, scientists have warned.
Greenland is losing ice seven times faster than in the 1990s, according to a study published in the journal Nature.
“As a rule of thumb, for every centimetre rise in global sea level another six million people are exposed to coastal flooding around the planet,” said one of the study authors Andrew Shepherd, Professor at University of Leeds in Britain.
“On current trends, Greenland ice melting will cause 100 million people to be flooded each year by the end of the century, so 400 million in total due to all sea level rise,” Shepherd said.
For the study, a team of 96 polar scientists from 50 international organisations combined 26 separate surveys to compute changes in the mass of Greenland’s ice sheet between 1992 and 2018.
Altogether, data from 11 different satellite missions were used, including measurements of the ice sheet’s changing volume, flow and gravity.
The findings showed that Greenland has lost 3.8 trillion tonnes of ice since 1992 — enough to push global sea levels up by 10.6 millimetres.
In 2013, the Intergovernmental Panel on Climate Change (IPCC) predicted that global sea levels will rise by 60 centimetres by 2100, putting 360 million people at risk of annual coastal flooding.
But this new study shows that Greenland’s ice losses are rising faster than expected and are instead tracking the IPCC’s high-end climate warming scenario, which predicts seven centimetres more.
So 40 million more people are likely to be exposed to coastal flooding by 2100 than earlier projected.
“These are not unlikely events or small impacts; they are happening and will be devastating for coastal communities,” Shepherd said.
The team also used regional climate models to show that half of the ice losses were due to surface melting as air temperatures have risen.
Onam celebrations in Kerala will be a low key affair as the state is recovering from devastating floods, the state Cabinet decided at its weekly meeting here on Wednesday.
Heavy rains have battered several districts of the state since the past fortnight leaving 125 people dead and destroying property worth crores. Over 6,000 people are still staying in 86 relief camps set up in the state.
Last year, the state government was forced to cancel Onam celebrations after the state witnessed similar floods and devastation.
Onam is the harvest festival of the state. It is primarily celebrated for three days, but the festivities continue for more than a week with educational institutions closed and the state holding cultural programmes in all the 14 district headquarters. This year however, the gala may be subdued.
The state government has announced distribution of Rs 10,000 relief payment to all the flood-affected families before September 7. The concerned secretaries and the village officials have been asked to distribute the compensation amount to the victims. (IANS)
Rain-swollen rivers in Bangladesh broke through at least four embankments, submerging dozens of villages and doubling the number of people fleeing their homes overnight to 400,000 in one of the worst floods in recent years, officials said Friday.
Heavy rains and overflowing rivers have swamped 23 districts in northern and northwestern Bangladesh, officials said. At least 30 people have been killed since the floods began last week.
“The government has opened more than 1,000 temporary shelters but due to deep waters and lack of communications, many people aren’t able to reach them,” Raihana Islam, an official in the flood-afflicted district of Bogra, told Reuters.
Islam said scores of people had instead camped on embankments, railway lines and highways, where traffic has come to a standstill. Aside from concern over crops, authorities are also worried that rising flood waters could take a toll on livestock.
South Asia receives monsoon rains between June and October that often lead to floods later in the season, but the intensity of the deluge in Bangladesh is uncommon. “The severity of the flood of this year is worse compared to recent years,” Ariful Islam, an executive engineer of Bangladesh Water Development Board, said.
The floods worsened after three embankments on the Brahmaputra river, which flows down from the Himalayas, through northeastern India and into Bangladesh, gave way late Thursday, said Mohammad Moniruzzaman, an official in the federal agriculture ministry.
“The onrush of water submerged a vast area along with several dozen villages,” he told Reuters.
Millions displaced in India
In the neighboring Indian state of Assam, floods on the Brahmaputra and its tributaries since last week displaced some 5.8 million people, but the situation has improved with waters receding, a state minister said.
“While some people have started going back to their homes, about 70% continue to remain in makeshift relief camps,” Assam Water Resources Minister Keshab Mahanta said.
Water levels were also coming down in the northern Indian state of Bihar, where floods have killed at least 78 people. “We are now taking measures to prevent outbreak of any disease,” Manish Kumar, the emergency officer at Bihar’s worst flood-hit district of Sitamarhi, told Reuters.
Two people died in Sri Lanka and five were missing because of heavy rain that forced hundreds to flee their homes across the island nation, the state-run Disaster Management Center said. The central districts of Nuwara Eliya and Ratnapura were the worst affected. (VOA)