Natural Disasters in Sri Lanka: past and future risks
Sri Lanka is quite a popular tourist destination for many countries around the world. Millions of tourists annually come here to relax on the marvellous beaches and experience the centuries-old culture of the island. And of course they should know in advance what natural disasters or catastrophes they may encounter. A natural disaster always comes unexpectedly, but knowing its potential can help you prepare for it.
Climatic characteristics of Sri Lanka
Sri Lanka is located in a subequatorial climate zone. Its weather is heavily influenced by the monsoon, a seasonal wind that blows in and out of the ocean.
During the summer, the south-western monsoon dominates, bringing heavy rainfall over most of Ceylon. In winter, the north-eastern monsoon blows with dry, cooler air.
The average temperature stays the same throughout the year. Humidity, on the other hand, increases in May and July.
Another feature of Ceylon is the absence of coral reefs along the coast. This makes the island defenceless against storms or tsunami waves.
In the central part of the island there is a mountain plateau, with high cliffs and peaks. After heavy rains, landslides are not uncommon in this region.
Tectonically, Sri Lanka lies on the Indian Plate, quite old and stable. There are no active volcanoes on the island and earthquakes are not severe.
Potential hazards that could cause a natural disaster include:
- Long coastline and lack of coral reef. It can threaten severe storms, high waves, including tsunamis.
- Seasonality of rainfall. Causes regular waterlogging, landslides in the mountains.
- Mountainous terrain. Carries the threat of rockfalls and landslides.
- Proximity to regions of high volcanic and seismic activity. Threatened by earthquakes and tsunami waves.
The importance of learning about the history of natural disasters in Sri Lanka
The history of natural disasters is important information to learn before travelling to your chosen country. Knowing the potential dangers that may be waiting for you, you can not only choose the right place, but also the time, the season of the year, when the threat of being at the epicentre of a natural disaster will be minimal.
For example, knowing that Sri Lanka is most vulnerable to storms in October and November, and that the south-west is flooded with heavy rains in summer, you may want to visit the country at a different time of year or place.
From this article, you will learn the chronology of natural disasters that have occurred in Sri Lanka in the past.
Sri Lanka itself is located in a tectonically calm area and has not experienced major earthquakes in a very long time. Historical records indicate that a major earthquake struck the area around 1481. It led to the collapse of the isthmus connecting Ceylon and India and the formation of the so-called Adam’s Bridge. But no exact information about that earthquake has survived.
The island is now mostly reverberating with earthquakes that have their epicentres in either northern India or Indonesia. Local residents do not notice these shocks, they are recorded only by special instruments.
However, the effects of strong earthquakes can cause serious damage, even at great distances. This happened in December 2004, as you can read below.
Tsunami killer waves pose a serious threat to Sri Lankan coastlines, as the island is not protected by a wall of coral reefs. Tsunamis occur after earthquakes, including underwater earthquakes, or volcanic eruptions.
The most catastrophic tsunami has occurred after the Greatest Earthquake on December 26, 2004. The epicentre of the earthquake was off the coast of the Indonesian island of Sumatra, and its magnitude exceeded 9. The tremors themselves were not felt in the Republic, but the tsunami caused enormous damage. The height of waves reached 15 meters in some places.
Authorities reported 30 thousand deaths. One and a half million more people were forced to leave their homes. The situation was complicated by outbreaks of infectious diseases, including cholera.
In the southwest, a tsunami destroyed a passenger train travelling from Colombo to Galle. It caused the deaths of 1700 people, making it the biggest railway disaster in history.
In Trincomalee, the tsunami wave travelled two kilometres inland. A military base was destroyed and hotels and shops damaged. Vast areas of rice fields were washed away.
At the time, many countries helped the republic to rebuild its economy.
Storms and hurricanes
The Indian Ocean has always had a reputation amongst seafarers as a very restless place with frequent storms. Sri Lanka, which lies in the heart of this ocean, experiences the full brunt of this neighbourhood every year.
The island’s worst storm season occurs in mid-autumn. But that doesn’t mean it’s very calm in the other months of the year. Tropical cyclones are notable for their year-round occurrence, and they can be expected to form during any season.
For example, in late January 2023, the first tropical cyclone of the season formed near Indonesia. It quickly enough reached the coast of Sri Lanka, but upon reaching land it immediately lost its full potential and became a simple strong wind.
Here is a list of other typical storms of recent years:
30 November 2017
A major storm with heavy rains hit the south of the island. A maximum red danger level was declared in five provinces of the country. As a result, four people died and 23 others are missing. Many resorts and towns were left without power and transport was disrupted.
20 May 2018
A severe storm hit the Eastern Province and the city of Trincomalee. The storm was accompanied by thunderstorms and lightning strikes killed 3 people. About 200 houses were damaged, and 250 people had to be evacuated.
9 December 2022
A strong cyclone passed along the coast of Ceylon on its way to India. It only touched the island by an edge, but caused severe air pollution. As a result, school classes were cancelled en masse in the country.
The most frequent floods hit Ceylon during May and early June with the arrival of the southwest monsoon. It is these winds that bring the maximum amount of rainfall from the vast Indian Ocean.
Thus, the 2021 season was particularly disastrous. At that time, heavy rainfall affected all southern and central provinces of the Republic.
In May 2021, Cyclone Yaas struck the island. It killed four people and affected more than 40,000. Many houses were washed away by the flood.
In June of the same year, a southwest monsoon brought record rainfall and caused flooding again. Roads and rice paddies were flooded. Fourteen people died and five more were reported missing. More than a thousand people were left homeless.
The May 2016 flooding was even more catastrophic, caused by the passage of Cyclone Roanu. A total of 101 people died and 100 more went missing. Five hundred houses were completely destroyed and one third of Colombo’s population was displaced. The total damage from the floods was $2 billion.
Heavy rains and floods in the mountainous areas of the island are often accompanied by landslides. In 2021, for example, several landslides occurred following catastrophic flooding, killing four people. Hundreds of houses were destroyed and highways damaged.
In May 2016, landslides in the country were catastrophic. Rescuers recovered 26 bodies from under the rubble in a 24-hour period on 21 May alone. A total of 82 people were killed by landslides. Three villages in the mountainous region of Kegalle were almost entirely destroyed by landslides. More than 400 people are missing.
This type of disaster is not typical of Sri Lanka, and no cases of catastrophic fires have been recorded here. However, due to climate change, the once permanently wet country has started to suffer from drought. Thus, in April 2019, Sri Lanka was hit by the worst drought in a hundred years. The abnormal heatwave lasted more than a week and 320,000 inhabitants experienced a shortage of fresh water.
The biggest threat to tourists in Sri Lanka are the violent storms for which the Indian Ocean is so famous. They are particularly strong during the autumn months of October and November. This period is called the off-season, when the monsoons subside for a while and the ocean roughness increases.
Therefore, autumn is considered the worst and most dangerous time of the year to visit Sri Lanka.
However, during the summer and spring there are frequent floods which can cause disturbance to the tourist centres.
Another serious danger is the constant threat of tsunamis. It is impossible to predict the occurrence of this wave because it is triggered by earthquakes or underwater eruptions. Such catastrophes occur regularly in the Pacific Ring of Fire, which runs through the islands of Indonesia.
There are no threats of volcanic eruptions, earthquakes or forest fires on the island.
The best time to visit the southwest coast of Ceylon is in winter, from late November to early March. The best time to visit the north-east coast of the island is summer, from late May to early October.