Features
The inexplicable rise of kidney disease in Sri Lanka’s farming communities
In the sleepy, verdant village of Ambagaswewa, in the Polonnaruwa district of Sri Lanka’s North Central province, 63-year-old TMH Gamini Sunil Thennakoon’s life is peaceful for the most part. On the brink of retirement, he still spends most days out working his rice paddies but is also content spending his days playing with his grandchildren and chatting with his wife and two daughters. Since boyhood, Thennakoon has farmed rice here across 2 hectares (20,000sqm). A majority-farming nation, agriculture plays a central role in Sri Lanka’s economy and constitutes 21.7 percent of total exports.
But for more than seven years, Thennakoon has been coping with unexplained kidney problems. The symptoms of his condition – abdominal and back pain – are not bad enough to require dialysis yet, but he does take tablets to keep the pain under control.
“I’m not sure what caused the issue, because the rest of my family seems fine,” he says calmly, his granddaughter straddling his lap. She reaches over to swipe at one of the puppies roaming the front porch of their home, where we’re sitting. Ambagaswewa, proliferated by rice paddies, is otherwise a jungle – birdsong twangs through the already humid morning air, luscious vines and creepers on the verge of overtaking farmers’ homes. It’s a peaceful place.
Every month, Thennakoon makes a round trip of more than 30km to a local government hospital for a check-up; during these trips, he has to hire labourers to work in the rice paddies and cover his absence.
Rice farmer Gamini Sunil Thennakoon, 63, pictured with his granddaughter, suffers from unexplained kidney disease [Al Jazeera]
Thennakoon is not the only one who has been affected in this way, here.
U Subasinha, a 60-year-old former rice farmer, is one of his neighbours. He has had a particularly hard life. One of his three children has been disabled since birth and, now aged 23, cannot walk. Seventeen years ago, Subasinha’s wife, Kamalavathi, now 54, started experiencing pain and was eventually diagnosed with chronic kidney disease.
Subasinha himself has suffered from acute kidney failure for the past eight years. He is so frail that he can barely leave his cramped, hot bedroom most days, let alone work. But for the past seven years, he’s been going for dialysis four times a week at a government hospital, more than 25km away.
He has to find the money for the medicine he needs (16,000 rupees or $54) a month for himself and Kamalavathi), and for the hefty transportation costs – upwards of $16 for the round trip of a bumpy, 45-minute tuk-tuk ride each way to the hospital in Polonnaruwa.
None of this is covered by any sort of government-provided healthcare. It’s a huge sum for a household without an income.
The couple says they have no idea what made them sick and they seem surprised at the question. “No one has ever come to ask us this before,” says Kamalavathi.

The rise of kidney disease ‘hotspots’
According to statistics from the National Kidney Foundation in the United States, 10 percent of the world’s population is affected by chronic kidney disease and it is the 12th most common cause of death. Millions die annually due to a lack of access to affordable treatment.
Furthermore, according to an analysis by the Global Burden of Disease Study in 2019, chronic kidney disease (CKD) has increased by 40 percent over the past 30 years and is one of the fastest-rising major causes of death. Common precursors to CKD include diabetes and hypertension – diseases increasingly endemic to urbanising populations.
But across rural Sri Lanka, there’s a relatively new phenomenon; “chronic kidney disease of unknown aetiology (cause)” (CKDu). A flurry of scientific research studies has provided no concrete reason as to why as many as 22.9 percent of residents in several “hotspot” areas in the north-central districts of Polonnaruwa and Anuradhapura, plus some neighbouring districts, are suffering from acute kidney damage or failure.
On a national level, 10 to 15 percent of Sri Lankans are impacted by kidney diseases, according to Nishad Jayasundara, who is from a farming community in Sri Lanka and now works as an environmental toxicologist at Duke University in Durham, North Carolina, US, and specifically researches the causes of CKDu.
“The disease disproportionately impacts farming communities,” he tells Al Jazeera. “The current estimates indicate that more than 20,000 people [in Sri Lanka] are at end-stage kidney failure, with no alternatives left, while 6 to 10 percent of the population in impacted communities are diagnosed with CDKu.”
Indeed, research published by the US government’s National Library of Medicine in 2016 states: “Geographical mapping indicates a relationship between CKDu and agricultural irrigation water sources in Sri Lanka”

A lack of early symptoms
While CKD has identifiable symptoms, such as weight loss and poor appetite, swollen ankles or hands, shortness of breath and itchy skin, early on, CKDu is asymptomatic until the latter stages of the disease, so early detection is nearly impossible, say doctors. By the time a patient receives a diagnosis, the disease is usually untreatable.
Even when symptoms do appear, they usually include back pain, swelling in the arms and legs and “body aches”, not uncommon for farmers and fishermen used to hard manual labour.
Dr S B A M Mujahith is a nephrologist – a doctor who specialises in treating kidney diseases – at Batticaloa Teaching Hospital on Sri Lanka’s eastern coast. He grew up just 50km down the coast from Batticaloa in the town of Nintavur and this played an important role in his career choice: “It was a community investment,” he tells Al Jazeera.
CKDu was first identified as an issue in Sri Lanka in the 1990s. There’s a geographical link, says Mujahith – some parts of the eastern and north-central provinces seemed especially hard hit. Many, like himself, wanted to investigate further and identify the causes.
A World Health Organisation (WHO) team even came to investigate the causes of CKDu in the 2010s, but ultimately the study was inconclusive.

Mujahith likes to use the term “chronic interstitial nephritis in agricultural communities” (CINAC) since the disease is rather specific to the nation’s agricultural workers. It affects mainly men – most patients live and work in poor agricultural communities and may be exposed to toxic agro-chemicals through work, inhalation, and ingesting contaminated water and food, explains Mujahith.
Sri Lanka, a small tropical nation with a population of about 22 million people, is undergoing the fifth year of the worst economic crisis in its history. The result has been limited access to medicine and food which hinders treatment and management of the disease, particularly in remote and under-served places such as Ambagaswewa.
‘Education is key’
Jayasundara, who grew up in a farming village in southern Sri Lanka, is currently working to isolate the factors of CKDu in his research, which examines phenomena such as how agrochemical concentration increases during drought (due to evaporation), or how the economic decline has affected the rest of the country.
Chronic disease in one specific organ of the body – in this case, the kidneys – can be a telltale sign of environmental harm, he says. “Sri Lanka serves as a clear example of how environmental change leads to so many downstream effects that affect people’s lives.”

The confounding cause of CKDu means it’s difficult to prescribe solutions for villagers, although those with the means are switching from drinking groundwater to filtered water.
Filtered water is not an option for many, however.
“If you’re choosing between food and sending your kids to school, you’re not going to be spending money on filtered drinking water,” says Sumuthuni Sivanandarajah, a marine biologist working at Blue Resources Trust, a marine research and consultancy organisation based in Sri Lanka.
Her work focuses on the self-employed fishing communities along the coasts of Sri Lanka, among whom kidney disease is also on the rise.
Sameera Gunasekara is a research scientist at Theme Institute in Sri Lanka exploring how climate change and diverse environmental exposures affect public health – specifically kidney diseases.
He agrees that the economic crisis has made it harder for people in remote farming and fishing communities to buy water filters. “People know, are conscious that clean water helps,” he explains. “But there’s some misunderstanding. [People] think that chlorinated water, or boiling, will help. That does with bacteria, but not the removal of hazardous materials.” The need for more education in these underserved regions is key, says Gunasekara.

Across the afflicted north-central farming provinces, Gunasekara is working to help educate the local population on reducing agrochemical usage, not staying in the sun for a long time, and preventing dehydration.
“Farming and fishing people have a stereotype, they are hard groups to convince,” the researcher continues. To begin with, biomarkers for the initial stages of the disease – back pain and leg swelling – are very subtle; not everyone experiences them. But even those who do experience them may not pay them heed.
“They just take a painkiller and get back to the field – they tend to suffer for a long time without doing proper [kidney] screening.” For many of these households, says Gunasekara, since the father is the only person earning money, the whole family collapses when he falls ill.
An economic crisis and chronic dehydration
Batticaloa on Sri Lanka’s east coast, known for both its aquaculture and agricultural activities, in the form of shrimp farms and rice and fish processing facilities, was the site of a brutal massacre during the nation’s relatively recent, long running civil war between the Sinhalese and Tamils. It is also one of the hotspots identified for the prevalence of CKDu, he says.
The civil war was an ethnic conflict that lasted for 26 years, ending in 2009 after killing more than 100,000 civilians and 50,000 soldiers from both the Tamil and Sinhalese sides.
Christy PL Navil, 58, has been working as a fisherman here for 12 years – before that, he worked as a helper on the boats. Along Pasikuda beach near Batticaloa, a landing site where 106 fishermen work each day, Navil fishes for calamari from 5am, not returning until the afternoon.
“Sometimes it’s many fish, sometimes it’s no fish,” he says. On the boat, they bring very little water considering the conditions – just 5 litres for two people to last for more than nine hours in the tropical heat. “The sun is hot, but we are just used to it. Sometimes fishing is busy, we aren’t drinking water or eating,” the fisherman admits. “We want to catch the fish.”
With the economic crisis, many fishermen also have to cut back on food, only taking one meal a day.

The resulting chronic dehydration is a major problem, says Sivanandarajah. She points to a combination of hereditary issues, water sources and pollution, toxins in agro-chemicals, anthropogenic factors (for example improper pesticide container disposal), and lifestyle issues as possible CKDu causes.
Some fishermen are accustomed to drinking local “arrack” – a form of liquor – to help manage seasickness, she adds. “This is wearing on the body, the kidneys. And with the rising temperatures, it may not be a root cause, but it’s definitely a stressor.”
The lack of formal fishing collectives or societies, the marine researcher continues, means that little is known about the impact of ocean resource depletion on these self-employed communities – or the subsequent health ramifications.
“Government officials lack the knowledge on how to communicate [with fishermen,] they don’t like being out in the field,” says Sivanandarajah. “Sri Lanka’s fisheries sector depends on politics, what the admin implements. No one knows about the fishermen’s income or situation on the ground. It’s very top down, and no one is actually doing anything with the data.”
Food scarcity is a major issue – particularly during the off-season and especially with the ongoing economic crisis, Sivanandarajah says.

There is also the high use of tube wells, inserted deep into the ground – deeper than wells – which extract very hard water as they break past phosphorus barriers in the earth which would normally act as a water softener, making the water easier on the human kidneys. “These became popular during the tsunami and monsoon seasons since ground wells are destroyed and contaminated by seawater,” Sivanandarajah explains.
Geological shifts linked to climate change can also increase the likelihood of earthquakes and volcanic eruptions, which in turn heighten the risk of tsunamis, say scientists. It is estimated that by the end of the 21st century, the global mean sea level will rise by at least 0.3 meters given current greenhouse gas emission rates, which would further inundate coastal communities with brackish water.
Crippling debt
Nadaraja Pereatambi, 62, has been working as a fisherman from Pasikuda beach since his youth. Two years ago, he was suffering from unexpected, acute kidney pain, culminating in an emergency operation and a 50-day hospital stay.
The treatment was largely successful – Pereatambi is cautiously back at work on the fishing boats. However, he had little choice but to take a 2 lakh loan (200,000 rupees, nearly $675 – an unthinkable sum for someone who makes as little as $4 a day, depending on the catch) to pay off the hospital bill.
“Six other fishermen working on this beach also have issues with kidneys,” he says. “Most have no money for hospital, even when suffering from kidney stones.”
It could be a water problem, he surmises. In the Pasikuda area, he continues, it is common knowledge that the water quality is poor: there’s too much calcium and fluoride, among other minerals: “It’s all very hard.”

Outside the government-funded District General Hospital in Negombo along Sri Lanka’s western coast, a little north of the capital city of Colombo, 48-year-old W Sirani Silva is easing into a tuk-tuk that her husband will drive her home in.
Two years ago, she found out she had acute kidney damage – with less than 10 percent function remaining – after experiencing nauseating back and stomach pain.
Each week, Silva makes the 20km journey twice for dialysis sessions in hospital, and is on the waiting list for a transplant. She is far too sick to take care of the house or her three children but is grateful that they are healthy. Since the onset of her illness, the family has switched to drinking filtered water, but still uses well water for cooking and other household needs.
Since Silva is so weak, her husband, K Usdesangar, 51, accompanies her to every dialysis visit, which means he loses income from working as a tuk-tuk driver – he was previously a fisherman – on those days.
“We have no idea where this comes from,” he says, since Silva had an otherwise clean medical history and never suffered from hypertension or diabetes, the main precursors for most kidney disease patients. “Perhaps, it just comes with the family.”
(Aljazeera)
Features
When floods strike: How nations keep food on the table
Insights from global adaptation strategies
Sri Lanka has been heavily affected by floods, and extreme flooding is rapidly becoming one of the most disruptive climate hazards worldwide. The consequences extend far beyond damaged infrastructure and displaced communities. The food systems and supply networks are among the hardest hit. Floods disrupt food systems through multiple pathways. Croplands are submerged, livestock are lost, and soils become degraded due to erosion or sediment deposition. Infrastructural facilities like roads, bridges, retail shops, storage warehouses, and sales centres are damaged or rendered inaccessible. Without functioning food supply networks, even unaffected food-producing regions struggle to continue daily lives in such disasters. Poor households, particularly those dependent on farming or informal rural economies, face sharp food price increases and income loss, increasing vulnerability and food insecurity.
Many countries now recognie that traditional emergency responses alone are no longer enough. Instead, they are adopting a combination of short-term stabilisation measures and long-term strategies to strengthen food supply chains against recurrent floods. The most common immediate response is the provision of emergency food and cash assistance. Governments, the World Food Programme, and other humanitarian organisations often deliver food, ready-to-eat rations, livestock feed, and livelihood support to affected communities.
Alongside these immediate measures, some nations are implementing long-term strategic actions. These include technology- and data-driven approaches to improve flood preparedness. Early warning systems, using satellite data, hydrological models, and advanced weather forecasting, allow farmers and supply chain operators to prepare for potential disruptions. Digital platforms provide market intelligence, logistics updates, and risk notifications to producers, wholesalers, and transporters. This article highlights examples of such strategies from countries that experience frequent flooding.
China: Grain Reserves and Strategic Preparedness
China maintains a large strategic grain reserve system for rice, wheat, and maize; managed by NFSRA-National Food and Strategic Reserves Administration and Sinograin (China Grain Reserves Corporation (Sinograin Group), funded by the Chinese government, that underpins national food security and enables macro-control of markets during supply shocks. Moreover, improvements in supply chain digitization and hydrological monitoring, the country has strengthened its ability to maintain stable food availability during extreme weather events.
Bangladesh: Turning Vulnerability into Resilience
In recent years, Bangladesh has stood out as one of the world’s most flood-exposed countries, yet it has successfully turned vulnerability into adaptive resilience. Floating agriculture, flood-tolerant rice varieties, and community-run grain reserves now help stabilise food supplies when farmland is submerged. Investments in early-warning systems and river-basin management have further reduced crop losses and protected rural livelihoods.
Netherlands, Japan: High-Tech Models of Flood Resilience
The Netherlands offers a highly technical model. After catastrophic flooding in 1953, the country completely redesigned its water governance approach. Farmland is protected behind sea barriers, rivers are carefully controlled, and land-use zoning is adaptive. Vertical farming and climate-controlled greenhouses ensure year-round food production, even during extreme events. Japan provides another example of diversified flood resilience. Following repeated typhoon-induced floods, the country shifted toward protected agriculture, insurance-backed farming, and automated logistics systems. Cold storage networks and digital supply tracking ensure that food continues to reach consumers, even when roads are cut off. While these strategies require significant capital and investment, their gradual implementation provides substantial long-term benefits.
Pakistan, Thailand, Indonesia, and Vietnam: Reform in Response to Recurrent Floods
In contrast, Pakistan and Thailand illustrate both the consequences of climate vulnerability and the benefits of proactive reform. The 2022 floods in Pakistan submerged about one-third of the country, destroying crops and disrupting trade networks. In response, the country has placed greater emphasis on climate-resilient farming, water governance reforms, and satellite-based crop monitoring. Pakistan as well as India is promoting crop diversification and adjusting planting schedules to help farmers avoid the peak monsoon flood periods.
Thailand has invested in flood zoning and improved farm infrastructure that keep markets supplied even during severe flooding. Meanwhile, Indonesia and Vietnam are actively advancing flood-adapted land-use planning and climate-resilient agriculture. For instance, In Vietnam’s Mekong Delta, pilot projects integrate flood-risk mapping, adaptive cropping strategies, and ecosystem-based approaches to reduce vulnerability in agricultural and distribution areas. In Indonesia, government-supported initiatives and regional projects are strengthening flood-risk-informed spatial planning, adaptive farming practices, and community-based water management to improve resilience in flood-prone regions. (See Figure 1)
The Global Lesson: Resilience Requires Early Investment
The global evidence is clear: countries that invest early in climate-adaptive agriculture and resilient logistics are better able to feed their populations, even during extreme floods. Building a resilient future depends not only on how we grow food but also on how we protect, store, and transport it. Strengthening infrastructure is therefore central to stabilising food supply chains while maintaining food quality, even during prolonged disruptions. Resilient storage systems, regional grain reserves, efficient cold chains, improved farming infrastructure, and digital supply mapping help reduce panic buying, food waste, and price shocks after floods, while ensuring that production capacity remains secure.
Persistent Challenges
However, despite these advances, many flood-exposed countries still face significant challenges. Resources are often insufficient to upgrade infrastructure or support vulnerable rural populations. Institutional coordination across the agriculture, disaster management, transport, and environmental sectors remains weak. Moreover, the frequency and scale of climate-driven floods are exceeding the design limits of older disaster-planning frameworks. As a result, the gap between exposure and resilience continues to widen. These challenges are highly relevant to Sri Lanka as well and require deliberate, gradual efforts to phase them out.
The Role of International Trade and global markets
When domestic production falls in such situations, international trade serves as an important buffer. When domestic production is temporarily reduced, imports and regional trade flows can help stabilise food availability. Such examples are available from other countries. For instance, In October 2024, floods in Bangladesh reportedly destroyed about 1.1 million tonnes of rice. In response, the government moved to import large volumes of rice and allowed accelerated or private-sector imports of rice to stabilize supply and curb food price inflation. This demonstrates how, when domestic production fails, international trade/livestock/food imports (from trade partners) acted as a crucial buffer to ensure availability of staple food for the population. However, this approach relies on well-functioning global markets, strong diplomatic relationships, and adequate foreign exchange, making it less reliable for economically fragile nations. For example, importing frozen vegetables to Sri Lanka from other countries can help address supply shortages, but considerations such as affordability, proper storage and selling mechanisms, cooking guidance, and nutritional benefits are essential, especially when these foods are not widely familiar to local populations.
Marketing and Distribution Strategies during Floods
Ensuring that food reaches consumers during floods requires innovative marketing and distribution strategies that address both supply- and demand-side challenges. Short-term interventions often include direct cash or food transfers, mobile markets, and temporary distribution centres in areas where conventional marketplaces become inaccessible. Price stabilisation measures, such as temporary caps or subsidies on staple foods, help prevent sharp inflation and protect vulnerable households. Awareness campaigns also play a role by educating consumers on safe storage, cooking methods, and the nutritional value of unfamiliar imported items, helping sustain effective demand.
Some countries have integrated technology to support these efforts; in this regard, adaptive supply chain strategies are increasingly used. Digital platforms provide farmers, wholesalers, and retailers with real-time market information, logistics updates, and flood-risk alerts, enabling them to reroute deliveries or adjust production schedules. Diversified delivery routes, using alternative roads, river transport, drones, or mobile cold-storage units, have proven essential for maintaining the flow of perishable goods such as vegetables, dairy, and frozen products. A notable example is Japan, where automated logistics systems and advanced cold-storage networks help keep supermarkets stocked even during severe typhoon-induced flooding.
The Importance of Research, Coordination, and Long-Term Commitment
Global experience also shows that research and development, strong institutional coordination, and sustained national commitment are fundamental pillars of flood-resilient food systems. Countries that have successfully reduced the impacts of recurrent floods consistently invest in agricultural innovation, cross-sector collaboration, and long-term planning.
Awareness Leads to Preparedness
As the summary, global evidence shows that countries that act early, plan strategically, and invest in resilience can protect both people and food systems. As Sri Lanka considers long-term strategies for food security under climate change, learning from flood-affected nations can help guide policy, planning, and public understanding. Awareness is the first step which preparedness must follow. These international experiences offer valuable lessons on how to protect food systems through proactive planning and integrated actions.
(Premaratne (BSc, MPhil, LLB) isSenior Lecturer in Agricultural Economics Department of Agricultural Systems, Faculty of Agriculture, Rajarata University. Views are personal.)
Key References·
Cabinet Secretariat, Government of Japan, 2021. Fundamental Plan for National Resilience – Food, Agriculture, Forestry and Fisheries / Logistics & Food Supply Chains. Tokyo: Cabinet Secretariat.
· Delta Programme Commissioner, 2022. Delta Programme 2023 (English – Print Version). The Hague: Netherlands Delta Programme.
· Hasanuddin University, 2025. ‘Sustainable resilience in flood-prone rice farming: adaptive strategies and risk-sharing around Tempe Lake, Indonesia’, Sustainability. Available at: https://www.mdpi.com/2071-1050/17/6/2456 [Accessed 3 December 2025].
· Mekong Urban Flood Resilience and Drainage Programme (TUEWAS), 2019–2021. Integrated urban flood and drainage planning for Mekong cities. TUEWAS / MRC initiative.
· Ministry of Agriculture and Rural Affairs, People’s Republic of China, 2025. ‘China’s summer grain procurement surpasses 50 mln tonnes’, English Ministry website, 4 July.
· National Food and Strategic Reserves Administration (China) 2024, ‘China purchases over 400 mln tonnes of grain in 2023’, GOV.cn, 9 January. Available at: https://english.www.gov.cn/archive/statistics/202401/09/content_WS659d1020c6d0868f4e8e2e46.html
· Pakistan: 2022 Floods Response Plan, 2022. United Nations / Government of Pakistan, UN Digital Library.
· Shigemitsu, M. & Gray, E., 2021. ‘Building the resilience of Japan’s agricultural sector to typhoons and heavy rain’, OECD Food, Agriculture and Fisheries Papers, No. 159. Paris: OECD Publishing.
· UNDP & GCF, 2023. Enhancing Climate Resilience in Thailand through Effective Water Management and Sustainable Agriculture (E WMSA): Project Factsheet. UNDP, Bangkok.
· United Nations Development Programme (UNDP), 2025. ‘Rice Bank revives hope in flood hit hill tracts, Bangladesh’, UNDP, 19 June.
· World Bank, 2022. ‘Bangladesh: World Bank supports food security and higher incomes of farmers vulnerable to climate change’, World Bank press release, 15 March.
Features
Can we forecast weather precisely?
Weather forecasts are useful. People attentively listen to them but complain that they go wrong or are not taken seriously. Forecasts today are more probabilistically reliable than decades ago. The advancement of atmospheric science, satellite imaging, radar maps and instantly updated databases has improved the art of predicting weather.
Yet can we predict weather patterns precisely? A branch of mathematics known as chaos theory says that weather can never be foretold with certainty.
The classical mechanics of Issac Newton governing the motion of all forms of matter, solid, liquid or gaseous, is a deterministic theory. If the initial conditions are known, the behaviour of the system at later instants of time can be precisely predicted. Based on this theory, occurrences of solar eclipses a century later have been predicted to an accuracy of minutes and seconds.
The thinking that the mechanical behaviour of systems in nature could always be accurately predicted based on their state at a previous instant of time was shaken by the work of the genius French Mathematician Henri Poincare (1864- 1902).
Eclipses are predicted with pinpoint accuracy based on analysis of a two-body system (Earth- Moon) governed by Newton’s laws. Poincare found that the equivalent problem of three astronomical bodies cannot be solved exactly – sometimes even the slightest variation of an initial condition yields a drastically different solution.
A profound conclusion was that the behaviour of physical systems governed by deterministic laws does not always allow practically meaningful predictions because even a minute unaccountable change of parameters leads to completely different results.
Until recent times, physicists overlooked Poincare’s work and continued to believe that the determinism of the laws of classical physics would allow them to analyse complex problems and derive future happenings, provided necessary computations are facilitated. When computers became available, the meteorologists conducted simulations aiming for accurate weather forecasting. The American mathematician Edward Lorenz, who turned into a reputed meteorologist, carried out such studies in the early 1960s, arrived at an unexpected result. His equations describing atmospheric dynamics demonstrated a strange behaviour. He found that even a minute change (even one part in a million) in initial parameters leads to a completely different weather pattern in the atmosphere. Lorenz announced his finding saying, A flap of a butterfly wing in one corner of the world could cause a cyclone in a far distant location weeks later! Lorenz’s work opened the way for the development branch of mathematics referred to as chaos theory – an expansion of the idea first disclosed by Henri Poincare.
We understand the dynamics of a cyclone as a giant whirlpool in the atmosphere, how it evolves and the conditions favourable for their origination. They are created as unpredictable thermodynamically favourable relaxation of instabilities in the atmosphere. The fundamental limitations dictated by chaos theory forbid accurate forecasting of the time and point of its appearance and the intensity. Once a cyclone forms, it can be tracked and the path of movement can be grossly ascertained by frequent observations. However, absolutely certain predictions are impossible.
A peculiarity of weather is that the chaotic nature of atmospheric dynamics does not permit ‘long – term’ forecasting with a high degree of certainty. The ‘long-term’ in this context, depending on situation, could be hours, days or weeks. Nonetheless, weather forecasts are invaluable for preparedness and avoiding unlikely, unfortunate events that might befall. A massive reaction to every unlikely event envisaged is also not warranted. Such an attitude leads to social chaos. The society far more complex than weather is heavily susceptible to chaotic phenomena.
by Prof. Kirthi Tennakone (ktenna@yahoo.co.uk)
Features
When the Waters Rise: Floods, Fear and the ancient survivors of Sri Lanka
The water came quietly at first, a steady rise along the riverbanks, familiar to communities who have lived beside Sri Lanka’s great waterways for generations. But within hours, these same rivers had swollen into raging, unpredictable forces. The Kelani Ganga overflowed. The Nilwala broke its margins. The Bentara, Kalu, and Mahaweli formed churning, chocolate-brown channels cutting through thousands of homes.
When the floods finally began to recede, villagers emerged to assess the damage, only to be confronted by another challenge: crocodiles. From Panadura’s back lanes to the suburbs of Colombo, and from the lagoons around Kalutara to the paddy fields of the dry zone, reports poured in of crocodiles resting on bunds, climbing over fences, or drifting silently into garden wells.
For many, these encounters were terrifying. But to Sri Lanka’s top herpetologists, the message was clear: this is what happens when climate extremes collide with shrinking habitats.
“Crocodiles are not invading us … we are invading floodplains”
Sri Lanka’s foremost crocodile expert, Dr. Anslem de Silva, Regional Chairman for South Asia and Iran of the IUCN/SSC Crocodile Specialist Group, has been studying crocodiles for over half a century. His warning is blunt.
“When rivers turn into violent torrents, crocodiles simply seek safety,” he says. “They avoid fast-moving water the same way humans do. During floods, they climb onto land or move into calm backwaters. People must understand this behaviour is natural, not aggressive.”
In the past week alone, Saltwater crocodiles have been sighted entering the Wellawatte Canal, drifting into the Panadura estuary, and appearing unexpectedly along Bolgoda Lake.
“Saltwater crocodiles often get washed out to sea during big floods,” Dr. de Silva explains. “Once the current weakens, they re-enter through the nearest lagoon or canal system. With rapid urbanisation along these waterways, these interactions are now far more visible.”
- An adult Salt Water Crocodile (Crocodylus porosus) (Photo -Madura de Silva)
- Adult Mugger (Crocodylus plaustris) Photo -Laxhman Nadaraja
- A Warning sign board
- A Mugger holding a a large Russell ’s viper (Photo- R. M. Gunasinghe)
- Anslem de Silva
- Suranjan Karunarathna
This clash between wildlife instinct and human expansion forms the backdrop of a crisis now unfolding across the island.
A conflict centuries old—now reshaped by climate change
Sri Lanka’s relationship with crocodiles is older than most of its kingdoms. The Cūḷavaṃsa describes armies halted by “flesh-eating crocodiles.” Ancient medical texts explain crocodile bite treatments. Fishermen and farmers around the Nilwala, Walawe, Maduganga, Batticaloa Lagoon, and Kalu Ganga have long accepted kimbula as part of their environment.
But the modern conflict has intensified dramatically.
A comprehensive countrywide survey by Dr. de Silva recorded 150 human–crocodile attacks, with 50 fatal, between 2008 and 2010. Over 52 percent occurred when people were bathing, and 83 percent of victims were men engaged in routine activities—washing, fishing, or walking along shallow margins.
Researchers consistently emphasise: most attacks happen not because crocodiles are unpredictable, but because humans underestimate them.
Yet this year’s flooding has magnified risks in new ways.
“Floods change everything” — Dr. Nimal D. Rathnayake
Herpetologist Dr. Nimal Rathnayake says the recent deluge cannot be understood in isolation.
“Floodwaters temporarily expand the crocodile’s world,” he says. “Areas people consider safe—paddy boundaries, footpaths, canal edges, abandoned land—suddenly become waterways.”
Once the water retreats, displaced crocodiles may end up in surprising places.
“We’ve documented crocodiles stranded in garden wells, drainage channels, unused culverts and even construction pits. These are not animals trying to attack. They are animals trying to survive.”
According to him, the real crisis is not the crocodile—it is the loss of wetlands, the destruction of natural river buffers, and the pollution of river systems.
“When you fill a marsh, block a canal, or replace vegetation with concrete, you force wildlife into narrower corridors. During floods, these become conflict hotspots.”
Past research by the Crocodile Specialist Group shows that more than 300 crocodiles have been killed in retaliation or for meat over the past decade. Such killings spike after major floods, when fear and misunderstanding are highest.
“Not monsters—ecosystem engineers” — Suranjan Karunaratne
On social media, flood-displaced crocodiles often go viral as “rogue beasts.” But conservationist Suranjan Karunaratne, also of the IUCN/SSC Crocodile Specialist Group, says such narratives are misleading.
“Crocodiles are apex predators shaped by millions of years of evolution,” he says. “They are shy, intelligent animals. The problem is predictable human behaviour.”
In countless attack investigations, Karunaratne and colleagues found a repeated pattern: the Three Sames—the same place, the same time, the same activity.
“People use the same bathing spot every single day. Crocodiles watch, learn, and plan. They hunt with extraordinary patience. When an attack occurs, it’s rarely random. It is the culmination of observation.”
He stresses that crocodiles are indispensable to healthy wetlands. They: control destructive catfish populations, recycle nutrients, clean carcasses and diseased fish, maintain biodiversity, create drought refuges through burrows used by amphibians and reptiles.
“Removing crocodiles destroys an entire chain of ecological services. They are not expendable.”
Karunaratne notes that after the civil conflict, Mugger populations in the north rebounded—proof that crocodiles recover when given space, solitude, and habitat.
Floods expose a neglected truth: CEEs save lives—if maintained In high-risk communities, Crocodile Exclusion Enclosures (CEEs) are often the only physical barrier between people and crocodiles. Built along riverbanks or tanks, these enclosures allow families to bathe, wash, and collect water safely.
Yet Dr. de Silva recounts a tragic incident along the Nilwala River where a girl was killed inside a poorly maintained enclosure. A rusted iron panel had created a hole just large enough for a crocodile to enter.
“CEEs are a life-saving intervention,” he says. “But they must be maintained. A neglected enclosure is worse than none at all.”
Despite their proven effectiveness, many CEEs remain abandoned, broken or unused.
Climate change is reshaping crocodile behaviour—and ours
Sri Lanka’s floods are no longer “cycles” as described in folklore. They are increasingly intense, unpredictable and climate-driven. The warming atmosphere delivers heavier rainfall in short bursts. Deforested hillsides and filled wetlands cannot absorb it.
Rivers swell rapidly and empty violently.
Crocodiles respond as they have always done: by moving to calmer water, by climbing onto land, by using drainage channels, by shifting between lagoons and canals, by following the shape of the water.
But human expansion has filled, blocked, or polluted these escape routes.
What once were crocodile flood refuges—marshes, mangroves, oxbow wetlands and abandoned river channels—are now housing schemes, fisheries, roads, and dumpsites.
Garbage, sand mining and invasive species worsen the crisis
The research contained in the uploaded reports paints a grim but accurate picture. Crocodiles are increasingly seen around garbage dumps, where invasive plants and waste accumulate. Polluted water attracts fish, which in turn draw crocodiles.
Excessive sand mining in river mouths and salinity intrusion expose crocodile nesting habitats. In some areas, agricultural chemicals contaminate wetlands beyond their natural capacity to recover.
In Borupana Ela, a short study found 29 Saltwater crocodiles killed in fishing gear within just 37 days.
Such numbers suggest a structural crisis—not a series of accidents.
Unplanned translocations: a dangerous human mistake
For years, local authorities attempted to reduce conflict by capturing crocodiles and releasing them elsewhere. Experts say this was misguided.
“Most Saltwater crocodiles have homing instincts,” explains Karunaratne. “Australian studies show many return to their original site—even if released dozens of kilometres away.”
Over the past decade, at least 26 Saltwater crocodiles have been released into inland freshwater bodies—home to the Mugger crocodile. This disrupts natural distribution, increases competition, and creates new conflict zones.
Living with crocodiles: a national strategy long overdue
All three experts—Dr. de Silva, Dr. Rathnayake and Karunaratne—agree that Sri Lanka urgently needs a coordinated, national-level mitigation plan.
* Protect natural buffers
Replant mangroves, restore riverine forests, enforce river margin laws.
* Maintain CEEs
They must be inspected, repaired and used regularly.
* Public education
Villagers should learn crocodile behaviour just as they learn about monsoons and tides.
* End harmful translocations
Let crocodiles remain in their natural ranges.
* Improve waste management
Dumps attract crocodiles and invasive species.
* Incentivise community monitoring
Trained local volunteers can track sightings and alert authorities early.
* Integrate crocodile safety into disaster management
Flood briefings should include alerts on reptile movement.
“The floods will come again. Our response must change.”
As the island cleans up and rebuilds, the deeper lesson lies beneath the brown floodwaters. Crocodiles are not new to Sri Lanka—but the conditions we are creating are.
Rivers once buffered by mangroves now rush through concrete channels. Tanks once supporting Mugger populations are choked with invasive plants. Wetlands once absorbing floodwaters are now levelled for construction.
Crocodiles move because the water moves. And the water moves differently today.
Dr. Rathnayake puts it simply:”We cannot treat every flooded crocodile as a threat to be eliminated. These animals are displaced, stressed, and trying to survive.”
Dr. de Silva adds:”Saving humans and saving crocodiles are not competing goals. Both depend on understanding behaviour—ours and theirs.”
And in a closing reflection, Suranjan Karunaratne says:”Crocodiles have survived 250 million years, outliving dinosaurs. Whether they survive the next 50 years in Sri Lanka depends entirely on us.”
For now, as the waters recede and the scars of the floods remain, Sri Lanka faces a choice: coexist with the ancient guardians of its waterways, or push them into extinction through fear, misunderstanding and neglect.
By Ifham Nizam
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