Cyclone Mahasen - A Case Study

Cyclone Mahasen is beginning to make landfall in the Bay of Bengal today...

A useful study for A level students is below:

Causes
A quick reminder of Hurricane formation is here. The shallow coastal shelf and warm seas in the Bay of bengal will channel Cyclones and magnify their strength as they approach land.

The path of the storm and its storm surge can be seen below:

Hazards
Tropical storms bring the fourfold hazard of strong winds, heavy rain, storm surges and large waves.As it goes these are not as severe as they could be since it satarted to make landfall at low tide and the winds have only been clocked at 60mph thus far. It has been reported as not being severe in twerms of these primary hazards but Bangladesh's low lying and flat terrain still make it susceptible to the secondary hazard of flooding from storm surges and the heavy rain may induce a secondary hazard - landslides.

Effects
Thus far, 2 people have been reported dead in Bangladesh and up to 50 Rohingya muslims being evacuated may have drowned as an evacuation boat capsized.
Dozens of houses collapsed in Patuakhali district as it inundated the land with waist deep water.
Though ti did not make landfall in Sri lanka, the heavy rain triggered mudslides and floods which killed 7 people.

Responses
Bangladeshi authorities have given out a warning level of 7 out of 10 for the incoming storm in the low lying areas around Chittagong and Cox's bazaar; a good example of identifying areas most at risk and focussing strategies to mitigate for hazard risk.
The main response has been the evacuation of large numbers of people from areas at risk. At least 956,372 people have been evacuated in Bangladesh to more than 3200 storm shelters. All schools and colleges and some hotels have been declared cyclone shelters. In Burma more than 160,00 people have been evacuated.
Bangladesh has also shut airports in the areas at risk.

Magnifying the Hazard
The presence of tens of thousands of Rohingya Muslims displaced by internal conflict last year in temporary refugee camps in Rakhine state has increased the overall risk from this storm.

Scale
In terms of the strength of the primary hazards it is not as large as it could be, but the scale in terms of area covered is still large - affecting 3 countries and millions of people. By contrast the Tornadoes in Granby in Texas (link here) have kileld at least 6 as a result of much more forceful wind but have affected a much smaller area of land, thus decreasing the overall risk of the hazard.

A link to the BBC news story on the event is HERE

Solving Global Water Problems

Year 10 pupils were set a task to research global water supply issues and attempt to solve them. Two excellent offerings are below:

Bangladesh Water Crisis from BSGeography

Water Shortages in China (and possible solutions) from BSGeography

What Causes Monsoons?

With the AS group looking at flooding causes and A2 at earth hazards, the video below on what causes India's monsoons may be useful:

The fearless ferrymen of Dhaka's Buriganga river

The article extract below is from the BBC news website. Follow this link: http://m.bbc.co.uk/news/magazine-19349949 to read the full article which gives an excellent insight into the scale of poverty and hardship for some people in Bangladesh:

25 August 2012 Last updated at 01:30

Rush hour in the Bangladeshi capital sees thousands of Dhaka's commuters boarding small wooden boats to cross the busy waters of the Buriganga river, one of the most dangerous waterways on Earth, especially for the ferrymen.

"To do this you need all your strength and courage. If you lose your bravery then you are finished."

Ferryman Muhammed Abdul Loteef takes passengers and goods across a quarter-mile (400m) stretch of the Buriganga river every day.

It is hard physical work in temperatures of up to 40C - especially for a 70-year-old.

There are few bridges across the Buriganga river. For the 25,000 people who commute every day between the city centre and the residential areas on the other side, the sampans - small wooden boats, powered and steered by one oar - are a lifeline.

The ferrymen must negotiate huge gravel barges, cargo ships and passenger boats, which dominate the river.

"Every day here one or two boats capsize," says Loteef.

"Sometimes small boats go under the big boats and people die."

There are no emergency services here. If there is an accident, it is up to the other boatmen to come to the rescue.

One of Loteef's friend's boats was hit by a launch a few months ago, when it was fullly laden with nine passengers.

"Of them, I rescued eight," he said. "They found the (other) body three days later," he says.

"It is our duty to save our passengers. Sometimes we risk our lives to save passengers."

For that dedication, there is not much financial reward. It costs two taka (just over £0.01 or under $0.02) to cross the river.

To make enough money to support his family, Loteef has to make the crossing more than 60 times a day, and sometimes works into the night.



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