Natural Disasters 3Wild Weather Deadly weather – cyclones, severe storms, storm surges, tornadoes, floods and extreme temperatures – often strikes with little warning time. In , severe storms occur more often than any other natural hazard.

Introduction World faces growing Two case studies … The second strongest In Victoria, a strong La but floodwaters gradually spread wild weather threat La Nina event on record Nina influence and warm downstream until much of Victoria 1 since 1918 gave much of 2 ocean temperatures around looked like an inland sea. Flooding ripple of air over warm, blue sea, a puff of cloud in the sky. Australia an unusual rainy season at Australia helped trigger record affected 75 towns. These major, Innocent enough, but is it the birth of a that the end of 2010 and in early 2011. humidity and heavy rain at the end riverine floods were some of the Amay kill hundreds, displace thousands and cause billions of Large areas of were of 2010. In January, more rain gave most extensive seen in Victoria. The dollars in property damage? Around the world, more than 1 billion flooded, including parts of Brisbane, the Campaspe, Lodden, Avoca SES answered thousands of calls people have lost their lives from weather and climate-related events and more than 78 per cent of the and Wimmera river catchments for help. Some floodwaters were over the past 60 years. They are the only category of natural disaster state was declared a disaster area. record flood peaks. After initial local 20 kilometres wide and damage has that is increasing in force and the number of deaths and amount Much of Australia was soaked. flash flooding, the weather cleared been estimated at $1.3 billion. Two “big wets” in 2011 show of destruction they cause. A leading natural disaster database the difference between flash and (NatCatService) shows that weather-related catastrophes have more riverine flooding. Flash floods can than tripled over the past 30 years. In alone, weather-related occur almost anywhere. Bursts 1 disasters have quadrupled since 1980. of heavy rain can be too much for Also, a report by the Geneva-based Internal Displacement drainage systems. On January 10, Monitoring Centre (IDMC) reveals the large number of people forced 2011, Toowoomba, in south-east from their homes because of sudden, natural disasters – 42 million Queensland, was struck by intense in 2010, 17 million in 2009 and 36 million in 2008. More than 90 per storms that dumped as much as cent of this displacement was because of weather-related disasters, 60 millimetres of rain an hour. This followed months of wet weather; the mostly floods and storms. ground was already saturated. Three Why are these disasters getting worse? Many experts are pointing natural creeks, which once flowed to climate change, with rising sea and land temperatures. They warn through the city, had been narrowed that record-breaking weather will only increase as our human impact and altered through development. on the environment grows. These streams swelled into raging “The intensity and frequency of extreme weather events are torrents that tore through the centre increasing, and this trend is set only to continue. With all probability, of town, picking up cars like toys. the number of those affected and displaced will rise as human- A mother and her 13-year-old son induced climate change comes into full force,” says the IDMC. died after making an emergency call for help. It was just one of the tragic And why do people in poorer countries suffer most? The stories to emerge from the disaster. International Disasters Database EM-DAT records that between Toowoomba sits on an escarpment 2 1991 and 2005, more than 90 per cent of natural-disaster deaths on the Great Dividing Range west of and 98 per cent of people affected by natural disasters were from Brisbane, about 700 metres above developing countries. sea level. Some of the water, as well Consider these examples. Cyclone Nargis, which struck Burma in as heavy rain falling on the slopes of May, 2008, was one of the deadliest storms in history. About 140,000 the range, quickly filled the creeks people died. High winds and a powerful destroyed running down to Lockyer Valley 700,000 homes in the coastal delta, killed three quarters of the below. The speed of flash floods livestock, sank half the fishing fleet and flooded rice paddies with salt here caught residents by surprise. Surging waters pushed water tanks, water. Burma’s military rulers were highly secretive about the damage, machinery, vehicles and buildings forcing international ships bringing aid to wait offshore for weeks. along roads and through paddocks, Record-breaking summer monsoon rains triggered massive sucked furniture and people from floods and landslides in Pakistan in July, 2010. With 1760 killed, it homes and destroyed buildings, was the world’s fourth deadliest natural disaster that year. A fifth of roads, rail lines and livestock. In all, the country was underwater for weeks, and 11 million people were 17 people died and three are still forced to leave their homes, with hundreds of thousands still living in missing. makeshift camps months later. The damage bill was $US9.5 billion, a heavy burden for an emerging economy. Flooding historically has been the worst of Australia’s natural disasters. (Although it is not well recognised, heat waves cause A deadly mix of factors the most deaths.) In the past two years, a strong La Nina, plus the highest sea temperatures measured off the Queensland coast, isastrous weather does contributed to unusually extreme weather – including a category not always arrive in the 5 cyclone (Yasi) in Queensland, plus heavy rain and floods in Dform of a severe cyclone. Queensland, Victoria and Western Australia. The weather, which swamped the island of in December 2011, was a tropical Tropical sea surface temperature was the highest on storm with winds of about 60 km/h record for the second half of 2010 and gusting to 100 km/h, but never reaching typhoon status. However, a number of factors combined to make this a major natural disaster. The region is mountainous, and when Tropical Storm Washi, or “Sendong”, dumped heavy rain – up to 200 millimetres over 12 hours – water gushed down hillsides, overwhelming rivers and flooding communities on the coast. Rescue operations at , Philippines. More than 1000 people died and 1582 were injured. Many people heightening the risk of disease. or lack of awareness, may have were washed away by flash-flooding Most fatalities were in two cities, been another factor in the disaster n Highest on record while they were asleep. Others were Cagayan De Oro and City, because Mindanao Island is not n Very much above average buried in landslides. although hundreds of those killed usually in the path of the 20 or so n Above average Deforestation had denuded hills, were in slum settlements along the typhoons that hit the Philippines n Average so rain water ran off quickly. River coast. Nearly 340,000 people were each year. n Below average n Very much below average systems in which river beds were affected by the disaster, with more Washi began on December 13 as n Lowest on record already silted, filled and overflowed. than 88,000 displaced and moved a tropical depression and intensified Families were swept out to sea to makeshift evacuation centres. to a tropical storm. Sep-Dec 2010, rainfall deciles (used to rank historic climate data). from coastal towns, and corpses More than 10,000 houses were See: earthobservatory.nasa.gov Courtesy National Climate Centre / Australian Bureau of Meteorology remained unburied for many days, damaged or destroyed. Surprise, /NaturalHazards/view.php?id=76702

NASA’s Aqua satellite shows approaching Some of the worst the Queensland coastline Fact file on February 2, 2011. One of , March 1899, North Queensland Australia’s biggest cyclones It was responsible for more deaths than any other natural disaster in Australia’s in a century, it devastated history. A category 5 cyclone, it killed about 400 people. No reliable records of wind speed exist, but barometer readings suggest central pressure was several towns and cut power 914 hPa (hectopascals), one of the most powerful to reach Australia. Central to 175,000 people. pressure is one indication of cyclone intensity; the lower the pressure, the Photo: Jeff Schmaltz / NASA greater the intensity. (, 1989, 905 hPa, 950 hPa).

Cyclone Tracy, December 1974, Darwin Tracy was a compact storm, just 50 kilometres wide but a powerful, category 4 cyclone. It swung over the Arafura Sea to hit a complacent Darwin early on Christmas Day. Fierce winds (217 km/h before the recorder was destroyed) How tropical cyclones Tornadoes in Victoria? We’ve seen a few and the inadequate design of many buildings meant the city was virtually destroyed. The storm killed 49 people in town and 16 more at sea. In a build their fury Tornadoes are violent, rotating A lightning storm over Sydney. Flash flooding in Melbourne. Cyclone Yasi’s destructive path. population of 43,000, 25,000 were left homeless. columns of air that touch down ome of the world’s wildest mass starts to rotate around a low- to earth in the well-recognised n Lightning causes 5 to 10 deaths Victoria are susceptible to flooding more than 2100 deaths in Australia weather comes in the form pressure centre. The rising, moist funnel shape from a storm cloud. and more than 100 injuries in at least once in a 100-year period. since 1839. Sof severe tropical cyclones, air cools and the water condenses The worst tornados can pack Australia each year. About 80 Most flood deaths occur when n Severe storms, with lightning, high also called hurricanes and typhoons. as rain. This condensation releases winds of more than 450 km/h. lightning-strike injuries result from people enter flood waters – in cars, winds and heavy rain, occur more They are spinning, low pressure latent heat from the warm vapour, We think of tornadoes as striking people using fixed telephones during boats, to swim or to play. often than any other natural hazard systems of torrential rain, thunder which is the source of energy for the mainly in the US and indeed, thunderstorms, when the phone n Victoria’s SES rescued two in Australia. and sustained, damaging winds of storm. This heat warms and expands 2011 was a deadly tornado year. system may become highly charged. teenagers who were riding a life- n Category 5 tropical Cyclone at least 118 km/h. They are referred the surrounding air so the cloud Preliminary figures show that n A lightning bolt can travel sized inflatable doll down the Yasi in 2011 wiped out nearly all to as hurricanes in the north Atlantic continues to grow. Because warm air in April alone, there were 748 at 160,000 km/h and reach swollen Yarra River in January 2011. of Australia’s banana crop and Ocean, the north-east Pacific is lighter than cold air, the pressure tornadoes, and 553 fatalities for temperatures of 28,000 degrees, n A typical tornado lasts for only a destroyed the popular resort of Ocean east of the dateline or in the drops further, and more air is sucked that year. Australia has them, hot enough to fuse soil and turn few minutes and every tornado has Dunk Island, which was then sold for south Pacific, east of 160 degrees in and up, continuing the cycle. too, the worst probably being in sand to glass. its own colour, sound and shape. a fraction of its previous value. east. Typhoon is the name used in If the atmospheric conditions are Brighton on February 2, 1918, n Most flash flood deaths occur at n Natural disasters, many weather- n More than 350 people, most of the north-west Pacific west of the right, the system will strengthen, causing widespread destruction. night, while more river flood deaths related, cost insurers $US110 billion them elderly, died from Victoria’s dateline. Australia uses the term with the clouds growing wider Bureau of Meteorology records occur during the day, according to in 2009, according to Swiss extreme heatwave in January/ Hurricane Katrina, August 2005, US Gulf of Mexico coast “tropical cyclone”. Other names are and deeper and the wind speed that Victoria has had 160 the State Emergency Service (SES). Re, a reinsurance company. In February 2009. High water temperatures intensified the storm to a category 5 hurricane. Wind used too, for example “severe” or increasing. Meteorologists use tornadoes since 1918, with more n Floods cost Victorians, on 2010, the cost almost doubled to n Heatwaves are Australia’s least gusts reached 340 km/h. Katrina made landfall near Miami, then destroyed “super” cyclonic storm when they satellite imagery, they watch the probably unseen or unreported. average, $465 million a year. About $US218 billion. recognised but deadliest natural offshore oilfields before again striking the coast close to New Orleans. occur in the north Indian Ocean. If system’s wind speed and use other Bendigo was struck by a 150,000 homes and businesses in n Tropical cyclones have caused hazard. Katrina’s storm surge broke the levees protecting low-lying New Orleans, and the sustained wind speed is less, techniques to track its development strong tornado in 2003. A tornado at Dimboola, western Victoria, 1992. 80 per cent of the city was flooded. More than 1300 people died. Millions of between 63 km/h and 117 km/h, the before giving it a name. people were left homeless. Losses totalled about $US125 billion. storm is called a tropical cyclone, It officially becomes a severe without the “severe”. tropical cyclone, hurricane or Wreaking havoc Tropical cyclone tracks, 1985-2005 Tropical cyclones form over typhoon when sustained wind Measuring the force, from 1 to 5 oceans roughly between the Tropic speeds reach about 118 km/h. n Tropical cyclones, through their of Capricorn and the Tropic of These complex, spiralling systems yclones, hurricanes The uses a 21 per cent the tropical cyclones ferocious winds, heavy rain that Cancer, beginning where there can be 500 kilometres wide, and typhoons are graded different hurricane intensity that reach land. causes flooding and water damage, is already low-pressure activity although they vary greatly. The is Caccording to their intensity. rating called the Saffir-Simpson Cyclone season in Australia is and through storm surges and disturbing the weather. Moisture normally 20 to 60 kilometres across. Different countries use different scale, also with a 1 to 5 rating. A nominally from November to April, sometimes tornadoes, can inflict evaporating from warm sea water, Severe tropical cyclones can intensity rating systems, but they category 1 hurricane packs winds although cyclones can occur significant damage when they strike with a temperature above 26.5 traverse the ocean gathering force, are all based on potential damage averaging 119 km/h to 153 km/h. outside of these months. The the coast. In hilly areas, rain can also degrees, starts to form a mass of but they lose power and dissipate from wind. In Australia, cyclones A category 5 has sustained winds earliest cyclone hit the north-west trigger mud and landslips, damaging cloud. As the water vapour rises, the when they cross onto a large land are given a category of 1(weakest) of more than 249 km/h. coast, near Broome, on 19 or destroying property and causing pressure falls and more air moves in mass, which cuts off moisture and to 5 (strongest), according to Generally, the damage November, 1910. loss of life. to fill the “gap”. Under the influence heat supply. wind speeds. The strongest, increases by a factor of four for One of the latest was on May n A storm surge is when low of the Coriolis effect, which is when The most damaging winds are which are extremely dangerous, each category increase. Category 21, 1998, over Shark Bay, about atmospheric pressure and strong the Earth’s rotation deflects the in the dense wall of thunderstorms have average wind speeds of 3, 4 and 5 hurricanes are referred 800 kilometres north of Perth. onshore winds in the cyclone cause Flooding in China, July, 1931 incoming air – to the right in the surrounding the calm centre, or eye. more than 200 km/h and gusts of to as “major” and they cause more The most cyclone-prone part of an upward bulge in the ocean. The Flooding along the Yellow River in 1931 is said to be the world’s worst natural northern hemisphere and the left in The storm’s outer rain bands can more than 280 km/h. Most of the than 83 per cent of damage in the Australia is the north-west coast force of the cyclone piles this high disaster. The death toll was estimated at 3.7 million. People lost their lives the southern hemisphere – the cloud extend hundreds of kilometres. damage is caused by fierce gusts. US, although they account for just between Broome and Exmouth. water up in a mound and pushes through drowning, disease and lack of food. The Yellow River has had many it ashore, inundating property and deadly floods and China has severe flooding in river systems every summer. Weather catastrophes worldwide 1980-2010 Measuring a storm threatening lives. In 2010, thousands died as heavy rains caused floods (below) and landslides. Number of events with trend Category Maximum mean Typical strongest Central pressure Typical A storm surge may be metres The Beijing Climate Centre says extreme weather events are increasing. wind (km/h) gust (km/h) (hPa) effects higher than a normal tide, with Go to: en.wikipedia.org/wiki/File:Global_tropical_cyclone_tracks-edit2.jpg Number n Meteorological events (storm) waves on top and stretching 1 63-88 < 125 > 985 Negligible house damage. Damage 1200 n Hydrological events (flood, mass movement) kilometres. Many people drown in to some crops, trees and caravans. n Climatological events (extreme temperature, drought, forest fire) storm surges around the world, Craft may drag moorings. including in Australia. In 1970 in 1000 2 89-117 125-164 985-970 Minor house damage. Significant Bangladesh, Cyclone Bhola pushed Learn more at: damage to signs, trees and caravans. one of the deadliest storm surges n bom.gov.au/cyclone/about/ 800 Heavy damage to some crops. Risk on top of a high tide, drowning more n ga.gov.au/hazards/cyclone.html of power failure. Small craft may than 300,000 people. n disasters.ema.gov.au/ break moorings. n ses.vic.gov.au 600 3 118-159 165-224 970-955 some roof and structural damage. n nhc.noaa.gov/ Some caravans destroyed. Power n munichre.com/en/media_relations/company_news/2011/2011-11-11_ company_news.aspx 400 failures likely (e.g. Winifred) 4 160-199 225-279 955-930 significant roofing loss and structural damage. Many caravans destroyed 200 and blown away. Dangerous airborne Flooding in Pakistan, July, 2010 Produced on behalf debris. Widespread power failures. of The Age by Record monsoon rains, which meteorologists say were linked by Clemson Text & Design. 0 (e.g. Tracy, Olivia) atmospheric conditions to severe heat waves and wildfires in Russia, caused Research and writing by unprecedented flooding and landslips in Pakistan. Flooding caused 1760 5 > 200 > 279 < 930 Extremely dangerous with Published by The Age Company Pty Ltd Leith Young.

2000 2002 2010 ABN 85 004 262 702 of 655 Collins Street, 1982 1992 2004 2006 2008 deaths, 1000 from flash floods and landslides in the Swat River valley near 1980 1984 1986 1988 1990 1994 1996 1998 widespread destruction. (e.g. Vance) Design by Docklands 3008. Source: © Australian Bureau of Meteorology Andrew Wolf. Peshawar. Because about 175 million people live in the Swat and Indus river © 2011 Münchener Rückversicherungs-Gesellschaft, Geo Risks Research, Series edited by Ben Haywood, manager, www.davidclemson.co regions, this was a humanitarian disaster. The damage totalled $US9.5 billion. NatCatSERVICE – As at January 2011 In Pakistan, a family waits for help. Education Resource Centre