BANGLADESH 1970 BHOLA CYCLONE AND NUMEROUS OTHER FLOODS

What was the deadliest cyclone in history?

1. Great Bhola Cyclone, Bangladesh (year) 1970, (Ocean Area) Bay of Bengal (Deaths)550,000

SOME CAUSES OF FLOODING

1. Monsoon climate 2. Spring snowmelt 3. Deforestation 4. River silt-up 5. Low elevation 6. Decreased wetland sedimentationdue to irrigation 7. Cyclones 8. Tsunamis (added by Mossa)

OROGRAPHIC PRECIPITATION

Orographic refers to mountains •Air forced upwards over mountains; When rises, it cools • Air masses decrease in temperature when rising

PREPARATIONS, BHOLA CYCLONE 1970

The Indian government received many ship reportson the cyclone • Indo-Pakistani relations were generally hostile, theinformation was not passed on to the Pakistanigovernment. • The Pakistan Meteorological Department issued areport calling for "danger preparedness" in thecoastal regions during the day on November 12. Asthe storm neared the coast, a "great danger signal"was broadcast on Pakistan Radio. • Much of the population in the area was aware of thecyclone before it hit, but only about 1% sought refugein fortified structures (largely because they did notexist)

Continentality

This seasonal reversal of wind direction andprecipitation is thus caused by the differential heating andcooling of landmass and oceans between summer andwinter.

CHERRAPUNJI, INDIA:

WETTEST PLACE ON EARTH elevation: 1400 m Precipitation: 11,777 mm (463.7 in)

BANGLADESH

• A country of southern Asia on the Bay of Bengal. Formerly part of Bengal, it became East Pakistan when Indiaachieved independence in 1947. After a civil war with West Pakistan (1971) culminating in military intervention byIndia, Bangladesh formed a separate nation. Dhaka is the capital and the largest city.• Population: 165,000,000 (as of 2018) (US: 330,0000,000). 56,980 mi² (147,600 km²) vs. 3,794,000 mi² (9,827,000km²), 66 times area

BANGLADESH AND CYCLONES

•Historically, Bangladesh has been hit by many cyclones•The massive population density coupled with the country's mostlyimpoverished people adds to the problems that cyclones bring.http://banglapedia.net/Maps/MC_0397.GIF

CHARS

Chars are small silt islands inthe Ganges-Brahmaputradelta. • On the mainland, a bigha (1/3of an acre) costs $75-$1750.On the char, it costs $2.50 .• On a char people can growenough food to subsist. Thereare one-room schools but noclinics, electricity, and doctors • Dhaka has overcrowding,hunger and unemployment.

RESPONSE

In the ten days following the cyclone, one militarytransport aircraft and three crop-dusting aircraft wereassigned to relief work by the Pakistani government.• The Pakistani government said it was unable totransfer military helicopters from West Pakistan as theIndian government did not grant clearance to cross theintervening Indian territory, a charge the Indiangovernment denied.• A week after the cyclone's landfall, President Khanconceded that his government had made "slips" and"mistakes" in its handling of the relief efforts. He saidthere was a lack of understanding of the magnitude ofthe disaster. He also said that the general electionslated for December 7 would take place on time,despite the poor state of impacted districts.

COMPARE AND COMBINE (Cyclone and Monsoon season)

Monsoon flooding season coincides with cyclone season

POST-1970 MITIGATION: SHELTERS

• After the 1970 cyclone, > 200 cyclone shelterswere constructed in coastal Bangladesh.• When the 1991 cyclones approached,volunteers warned people 2-3 days beforelandfall. Over 350,000 people fled to shelters,other brick structures, or high ground.• Cyclone shelters were few in relation to need• At least 20% more deaths would have occurredin the absence of these shelters.• Now, Bangladesh has more than 14,000shelters, which have the capacity toaccomodate 2.4 million people. As a result,over the last 25 years, the number of fatalitieshas been reduced by 75%.

1970 BHOLA CYCLONE

• Deadliest cyclone in human history• Not particularly strong, 115 mph max winds (111mph = Cat 3) • Storm surge (~10m), lack of preparation and poor responsewere causes for the catastrophic amount of deaths (>500,000) • From 1955-1971, Bangladesh= East Pakistan, part of Pakistan

PRECEDENT: A HISTORIC CONCERT

• George Harrison turned music into a political andsocial force. In August 1971, he staged two concerts atNew York's Madison Square Garden with fellowmusicians to alert the world to the plight of theBangladeshi people.• They were ravaged by floods, famine and civil war,leaving 10 million people fleeing their homes.• Harrison set the precedent that music could be usedto serve a higher cause.• The Concert for Bangladesh produced >$15 million forUNICEF. The concert was released as a triple-albumboxed set December 1971 and a feature film in 1972.That year, it won the Grammy for best album.

BANK EROSION

• In Bangladesh, each year over 10,000 ha ofriverbank are lost and 1,000,000 people aredisplaced due to bank erosion • Leads to avulsions, abandoned courses, etc. • Engineering approaches to reduce bankerosion are expensive and not necessarilyeffective

MONSOON

• January: Land is cooler than ocean, H over land (cold airmore dense), offshore wind (H to L), dry because of source• July: Land becomes warmer than ocean, L over land (warmair less dense), onshore wind (H to L), wet because of source• Continentality: This seasonal reversal of wind direction andprecipitation is thus caused by the differential heating andcooling of landmass and oceans between summer andwinter.• 'Monsoon' is derived from the Arabic, meaning seasons.• The lifting of the summer wet air masses over the Himalayas(orographic) brings lots of rainfall

LARGE RIVERS:GANGES AND BRAHMAPUTRA

• The Ganges and the Brahmaputra are the two large rivers thatflow through Bangladesh. This delta plain has built up thecountry through regular avulsions.

SOON AFTER: FLAG OF BANGLADESH

• The Pakistani government was severely criticized for itshandling of the relief operations following storm, both by localpolitical leaders in East Pakistan and by international media.• The opposition Awami League gained a landslide victoryContinuing unrest between East Pakistan and the centralgovernment triggered the Bangladesh Liberation War in 1971• Concluded with the creation of Bangladesh, later in 1971.• Flag: The red disk represents the rising sun and the sacrifice toachieve independence; the green field symbolizes the lushvegetation of Bangladesh.