How Countries are Preparing for Climate Change - 3a Extreme Weather - Severe Storms, Rain Bombs, Cyclones and Typhoons
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| -Image by Copilot |
Countries Currently Experiencing Extreme Weather
China (southern provinces — Hainan, Guangdong, Zhanjiang area) — Typhoon Matmo made landfall in southern China with torrential rain and strong winds, evacuations and transport disruptions reported.
Vietnam — Heavy rain from Typhoon Matmo has caused renewed flooding in Hanoi and northern provinces; authorities warn of more storms possible.
India (northeast / Darjeeling region and parts of western India) — Persistent heavy rains triggered deadly floods and landslides in Darjeeling and nearby districts; separate post-monsoon cyclone activity (Cyclone Shakhti) has threatened western coastal areas (Gujarat, Maharashtra).
Nepal — Severe rainfall and landslides in recent days with significant casualties and ongoing rescue operations.
In Bhutan — Reports of extremely heavy rainfall and flood/landslide destruction across southern regions tied to the recent low-pressure systems.
Philippines, Taiwan, Hong Kong — These areas were battered recently by Super Typhoon Ragasa (late Sept); ongoing recovery and local flooding/storm-damage reports continue in places still affected.
Mexico (Pacific coast / Guerrero, Michoacán) — Hurricane/tropical system Priscilla formed off Mexico’s Pacific coast, producing dangerous waves and heavy rain — coastal flooding/wave hazards reported.
Oman (and parts of the Arabian Sea region) — Cyclone Shakhti (post-monsoon Arabian Sea system) has been tracked as it moves and generates rough seas and heavy rain affecting western India and nearby coasts including Oman.
Ghana- Many parts of the country are flooding due to heavy rain over several days
Japan has been experiencing violent windstorms and flooding. Arizona has been hit with torrential flooding. Severe floods and landslips have also occurred in Panama.
Things aren't looking much better in Europe. Roads have turned into rivers in France. Northern Italy has been battling severe storms. Spain is experiencing severe flooding after intense rain. Devastation continues in Bulgaria and not even Norway has been spared. This isn't even a full list, but I'm sure you get the idea. Egypt, Sudan and Ethiopia are today's additions. Before I continue, here are some definitions:
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| -Image by Copilot, info from Wikipedia |
More New Words
Medicane sounds rather like something you might take for a headache, but it is used to describe the cyclone -like phenomenon which has brought heavy flooding to Spain and Greece in recent years. Seldom reaching more than Cat 1-2, they are slow moving systems, but they are becoming increasingly common.
Freak wind gusts called Microbursts may also occur. These happen when a
column of air - wet or dry, suddenly plummets to earth. Although only small
in comparison to cyclones - only 1 -3 km (up to 2 mi) wide and only of 5 to 15 minutes duration, they too can be very destructive. They have caused air crashes, brought
down trees and powerlines and are believed to have been responsible for a Jumping Castle tragedy in Devonport, Tasmania. The castle was lofted 20 metres into the air, leading to the deaths of six primary
school children and causing injuries to others.
Rain Bomb is another term which has entered our weather lexicon. It is used to describe a very heavy rainfall in a short space of time, leading to flash flooding, landslides and extensive damage to homes
and infrastructure and sometimes, because of their sudden onset, also loss of life.
By way of example, Brisbane received 60% of its annual rainfall in three days in 2022 - almost as much as London gets in a whole year, causing much devastation and loss of life. In July 2025, young people attending a summer camp in Texas were swept away as the river rose almost 8 m in 45 minutes due to flash flooding. In Argentina in May 2025, between 8 and 15 inches (300 and 400 mm) of rain fell within 72 hours in a region which normally only receives 1.7 inches a month.
Last year's Typhoon Haikui (2023 brought more rain to Hong Kong than it usually receives in a year, in fact, it was the heaviest rainfall since records began in 1884. This resulted in flooding of its subway stations which literally brought the city to a standstill. Hurricane Eta which raged across Central America in 2020, dumped 100 mm (4 ") of rain on Nicaragua, 260 mm (10") in Honduras and 300 mm (12") on Guatemala in just 24 hours.
According to Climate Central, nearly 90% 0f US cities have experienced an increase in hourly rainfall since 1970.
Why it's happening
The reason we are getting heavier rainfalls and more destructive winds and cyclones appears to be primarily linked to ocean warming and climate change. As temperatures rise on land and sea, there is more evaporation and hence more moisture in the atmosphere. For every degree of warming the atmosphere can absorb another 7% more water. The added moisture fuels more intense storms and can turn them into cyclones or rain bombs. According to the latest Climate Council report, the frequency of such events is likely to double with each degree of global warming.
While the overall number of cyclones in the Atlantic is currently about the same or may even decrease, the proportion of Category 4 and 5 cyclones is increasing. These storms bring stronger winds, higher storm surges and more destructive rainfall. Cyclones are also lingering longer over land, increasing flood risk and intensifying rapidly, leaving little time for people to prepare or evacuate.
Researchers at Hong Kong City University say the territory usually has around six typhoons annually but this year it has already had nine and they are not only becoming more frequent, but more powerful as well.
They are also occurring in places which rarely or never had them before. Take New Zealand's Cyclone Gabrielle for example, which occurred in Feb 2023. Cyclones usually weaken before they reach these latitudes, but in this case it caused widespread flooding, triggered over 800,000 landslides and caused 11 direct deaths well as making it the costliest cyclone in the Southern Hemisphere.
As I was writing this, a Hydro electric dam in Vietnam burst after receiving 1600 cubic metres of water per second during Typhoon Matmo. During the passage of Typhoon Ragasa only a few days earlier, China had to evacuate 1.9 million people in the province of Guangdong and shut down schools, factories and transit services. Streets in Hong Kong were also deserted as "waves taller than lamp posts" struck."
Protecting the People
As with wildfires, until recently 97% of disaster expenditure has been on response and recovery, but as costs and the human toll from repeated natural disasters keeps growing, focus is shifting to prevention in this case too.
We have already discussed many of these modifications when we talked about coastal flooding and storm surges in Part 1, so I don't want repeat them too much, but I will add a few points which I have learnt about in the meantime. We do need to move people away from flood plains if possible, and also need to be changing our building regulations to take into account higher rainfall and stronger winds. We also need to continually upgrade our drainage systems to accommodate larger flows, as Japan and many other countries are finding out.
Nature - based flood mitigation involves the use absorbent surfaces such as wetlands, permeable pavements and green roofs to take up excess water that can then be slowly released back into the environment so that it doesn't cause flash flooding. And let's not forget the power of trees to intercept winds and reduce their velocity. Just don't plant them too near the house! They also do much to stabilise soils against landslips and storm surges.
In this context I should also mention that some farmers in the UK are putting bends back into rivers which had previously been straightened, so that water flow slows down and allows more water to percolate into soils and groundwater.
Improved Infrastructure and planning
Post Hurricane Katrina New Orleans is an excellent case study in flood water management. During Hurricane Katrina (2005), 80% of this low lying coastal city was flooded, thousands lost their lives and were displaced and the economic losses in today's figures, are estimated to have been in the order of $US 201.3 billion, making it one of the costliest natural disasters in US history. Since then, New Orleans has spent $US 14.5 billion upgrading its flood defences. Here are some of the measures it has taken:
- Strengthening and increasing the height of its levees
- Adding flood walls and gates – its Lake Borgne Surge Barrier is currently the largest surge barrier in the world
- It has added powerful pumping stations that can remove million of gallons of water in minutes to keep flood water out of the city
- It has restored wetlands and barrier islands because they are the first line of defence against storm surges
- Added Green Infrastructure such as permeable pavements, rain gardens and green roofs to absorb rainwater and reduce pressure on drainage systems.
- The city is also adding climate -resilient infrastructure, including stronger buildings and flood-proof structures, to protect its residents and economy.
The Trouble with Dams
Traditionally, aside from their other uses in water supply and power generation, dams have been used as a flood mitigation measure. However, under increasingly volatile weather conditions and increased flows, they are not always effective and can pose their own risks. One of the reasons for the excessive death toll in the Brisbane floods of 2011, was that water had to be released from the Wivenhoe Dam upstream to prevent it collapsing due to the high volume of water. Had that happened, the death toll would have been far higher. A list of dam failures generated by ChatGTP follows:
Dam Failures Triggered by Excessive Rainfall
Libya (2023): During Storm Daniel, the Derna and Abu Mansour dams collapsed, causing a tsunami-like flood that killed 6,000 to 20,000 people. The dams were small but poorly maintained.
Sudan (2024): The Arbaat Dam failed during heavy monsoon rains, killing over 60 people and destroying 20 villages.
Brazil (2024): A hydroelectric dam in Rio Grande do Sul burst after days of rain, leaving 300,000 people without power.
Kenya (2024): A dam north of Nairobi collapsed during historic rainfall, causing widespread flooding and fatalities.
Norway (2023): The Braskereidfoss dam broke after heavy rain, but timely evacuations prevented deaths.
USA (2020): The Edenville and Sanford dams in Michigan failed after intense rainfall, leading to mass evacuations and infrastructure damage.
China (1975): The Banqiao Dam collapse—triggered by Typhoon Nina—remains one of the deadliest dam failures, with 171,000 fatalities.
Apart from issues such as poor maintenance and aging, a major reason for the collapse of dams is that they were designed using now outdated climate data. Obviously older dams and infrastructure must be inspected for strength and capacity to accommodate the new weather regime and the one we are likely experience in future. Alternatives include smaller deeper dams, which also reduce evaporation, the use of surge tanks, and uptake of excess water in household tanks.
Surge Tanks, Tunnels and Barriers
Japan, Hong Kong, Denmark, and South Korea use large underground surge tanks to accommodate periodic flooding. Mexico has also vowed to build a deep surge tank after its latest brush with flooding.
- Japan's was the first and is also the largest. Completed in 2006, its system of five huge underground shafts and pumps carry excess water from Tokyo's five smaller rivers via 6.3 km
of tunnels and pump it into the larger Edo River, thus largely preventing flooding of urban areas. However, Japan’s rainfall intensity has nearly doubled since the1980s, with more frequent events exceeding 100 mm (3-4 ") per hour. Climate change has also extended
typhoon seasons and made rainfall patterns more erratic.
In consequence, although Tokyo Metro and Toei Subway have elevated entrances, watertight doors, barriers to prevent street-level water intrusion and anti -flood sensors embedded in street grates to detect and block incoming water, some stations still flooded in its most recent floods. In anticipation of worse to come, subway operators are now working to make them able to withstand six metre floods rather than two.
Japan has developed a compact modular radar which gives early warning of heavy localised rain and will be particularly useful in remote areas and where rainfall diverges greatly from centralised forecasts. This is particularly true of mountainous regions such as Korea, New Guinea and possibly the South Island of New Zealand. Hong Kong - which receives both monsoons and typhoons, has had a similar system of giant surge tanks and tunnels since 2009 - again after devastating floods and downpours in 2008. The system diverts water pouring down the mountains, away from its Central Business District, through the mountain and to the other side or into the harbour. The largest tank is directly below its Happy Valley Race Course which used to flood regularly. Now this water is being earmarked for irrigation and the toilets of nearby housing estates, an idea definitely worth emulating. Rural communities are protected by dykes and channels.
A mobile phone App warns residents when "Black Rain" or Typhoons are expected, so that they stay indoors and avoid unnecessary travel. Although the system has so far prevented serious flooding Edward Ng, professor of architecture at the Chinese University in Hong Kong, warns against complacency. Although speaking mainly about coastal flooding he says," “It (the drainage system) can cope with what happened thirty years ago, but not with what will happen in the next fifty years.”
- Copenhagen's surge tanks were part of its massive new storm water upgrade after flooding in 2011. Once floodwaters soak through its porous paving, they are held in huge underground tanks. What isn't needed for parks or other purposes, is then pumped into the harbour- rather than allowing them to overwhelm the city or its sewerage system. See also its rain parks in the following video. You may also notice its raised kerbs and flood barriers.
South Korea: Unfortunately - as with aeroplane crashes, it took another disaster for South Korea to begin its flood prevention strategy. It wasn't a cyclone, but two days of torrential rain in August of 2022, in which 17" of rain (141.5 mm) per hour fell on low lying areas of Seoul. Nine people lost their lives and 2,800 houses were damaged. The city then pledged to ensure that no person would ever again be put in harm's way through flooding.
It's flood prevention strategy included increasing the capacity of its drainage system and the building of underground rainwater storage tunnels and surge tanks, especially in those areas which had been hardest hit, such as Gangnam Station. These tunnels aim to handle up to 110 mm of rainfall per hour, up from the previous 95 mm capacity. Seoul also uses portable water-blocking boards for flash flood response at subways and underground apartments.
The city’s real-time flood prediction system integrates data from precipitation, topography, and drainage infrastructure to guide evacuations and interventions.
- To get a glimpse of how Germany is managing its floods, see this video about the small village of Döblen, near Dresden or how the mighty Danube, is being kept in check.
As part of their flood defences Berlin, Hamburg and Munich have steps at the entrances to their subways which first go up, before descending into the depths to stop water coming in. [A simple and inexpensive idea for Japan if that hasn't been done yet]. Some subways also have hidden barriers or floodgates.A German Company has developed the “LauternBarrier” a self- closing concrete barrier to protect underground facilities such as parking garages and building entrances. Its advantage is that it deploys automatically and it doesn’t require someone to set it up, which could be vital in situations where flooding comes quite unexpectedly as occurred in Germany’s Ahr Valley in 2021.
Early Warnings and Public Awareness
There are several lessons to be learned from what has been one of Germany's deadliest and costliest disasters in modern times.The Ahr Valley flood caused "unprecedented" loss of life - (134 people) and property damage of around €33 billion as 8,800 homes were damaged or destroyed, along with the majority of the region's famous vineyards.
- The first is that its flood maps hadn't been updated since 1947, thus many people received no warning or evacuation orders.
- The rainfall, at 150 mm per hour (almost 5") was so far in excess of the usual rainfall that its rainguages were too small to measure it accurately e
- Even when authorities had some idea, neither they, nor residents could believe what was happening.
Australians all along the East Coast, had much the same incredulous response when they were suddenly told to prepare for Cyclone Alfred. Australia's cyclones usually occur only in the Top End - around Karratha in Western Australia and Far North Queensland. Beyond that, people have little idea what to expect. Resources and Emergency personnel were called in, even the Army.
As it happened, Alfred quietly made a right turn just before hitting the City, everyone breathed a sigh of relief, complained loudly about the Bureau of Meteorology's forecasting and went back to what they were doing. Imagine if the cyclone had hit and the warnings had not been issued? We'd be sitting there like the remaining residents of Ahr or the people of Darwin in 1974. Think of it as a drill.
Darwin had never had a serious Cyclone either until Cyclone Tracy came along on Christmas Eve, in 1974 and flattened 70% the town. The cloud mass had been seen on satellites, but had been expected to pass to the north of Australia, before it abruptly turned right. When Darwin was rebuilt, it was built to cyclone code - buildings were stronger and more substantial and each one had at least one reinforced inner room -usually the bathroom, which was cyclone -proof.
People in cyclone -prone regions or those with high winds - e.g. in 'Tornado Alley' in the USA, already have storm shelters, shutter their windows and evacuate in the event of a storm, but the rest of us have little idea. Here's what's happening in countries which have had to live with extreme weather and natural disasters.
Preparing for Floods and Cyclones
Anticipatory Action Systems – Global Aid Shift
Internationally, there is also a shift from reactive response to anticipatory aid. Aid groups are now deploying resources before disasters strike. For example, the Uganda Red Cross used storm forecasts to distribute water purification tablets ahead of flooding. Other forms include funds which pay out money for evacuations and the like before a disaster strikes, although there is still considerable debate about how such funds should be managed and allocated.
People complain about the cost of such preparations, about the cost of their power bills and about the cost of getting to Net Zero, but when you add up the costs -human and economic, of natural disasters, they are far greater than these. The USA alone has had 403 disasters in excess of $USD 1 billion between 1980 and and 2024 and totalling $2.19 trillion. Furthermore, such events have increased from approximately 9 per year, to 27 per year over the last 5 years.
A Word About High Tech Solutions
Ocean Cooling
Cyclogenesis
An international team with its headquarters in Canberrra is looking at cyclone dynamics in order to lessen their intensity. So far cloud seeding has shown the most promise and current efforts are about modelling the impact of aerosols in order to intercept and prevent the rapid intensification of cyclones.
Geoengineering
- Solar Radiation Management which can take the form of Stratospheric Aerosol Injection or Marine Cloud Brightening
- Carbon Dioxide Removal from the Atmosphere - several different methose as detailed below, none of which have so far proved very successful
Main Geoengineering Approaches
| Type | Mechanism | Risks & Concerns | Sources |
|---|---|---|---|
| Solar Radiation Management | Reflects sunlight to cool Earth (e.g. aerosols, cloud brightening). | Alters rainfall, disrupts monsoons, may damage ozone, uneven regional effects. | CIEL |
| Stratospheric Aerosol Injection | Sprays particles (e.g. sulfur dioxide) into the stratosphere. | Ozone depletion, reduced rainfall, unpredictable climate feedback. | Live to Plant |
| Marine Cloud Brightening | Sprays sea salt into clouds to increase reflectivity. | Regional weather shifts, ecological uncertainty, limited scalability. | Sustainability Directory |
| Carbon Dioxide Removal | Extracts CO₂ via biological, chemical, or mechanical methods. | Energy-intensive, slow impact, land-use conflicts. | CIEL |
| Ocean Fertilization | Adds iron to stimulate phytoplankton growth for CO₂ absorption. | Algal blooms, oxygen depletion, marine dead zones. | Live to Plant |
| Direct Air Capture | Machines pull CO₂ directly from ambient air. | High energy demand, costly infrastructure, toxic waste risks. | Sustainability Directory |
| Enhanced Weathering | Spreads crushed minerals to bind atmospheric CO₂. | Soil disruption, heavy metal leaching, uncertain long-term effects. | CIEL |
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