By June 2024, Sri Lanka was grappling with a severe flood crisis that had caused widespread devastation across multiple regions. Heavy rainfall had led to significant flooding and landslides, particularly affecting the southwestern and northeastern districts. The Disaster Management Centre (DMC) reported substantial impacts, including at least 17 fatalities and the displacement of over 85,000 people. The recent floods wreaked havoc, disrupting the lives of hundreds of thousands of individuals. The worst-hit districts included Colombo, Gampaha, Kalutara, Galle, Ratnapura, Ampara, and Badulla. Of particular concern were the areas around the Deduru Oya valley, which remained under continuous flood warnings due to rising water levels.
The heavy rainfall had been relentless, with some regions receiving over 250mm of rain within a 24-hour period. Agalawatta in the Kalutara district recorded a staggering 336mm of rain, exacerbated by the storm "Tauktae." This intense and sudden deluge overwhelmed both natural and man-made drainage systems, leading to widespread flooding.
The immediate consequences were catastrophic. Nearly 300 homes were damaged, with many completely destroyed. Infrastructure took a significant hit, with roads, bridges, and train services disrupted, causing major delays in commercial and regional transportation. The Sri Lankan Navy and Army were deployed for rescue operations, yet the scale of the disaster overwhelmed these efforts.
The human toll was tragic. At least 30 people lost their lives, and over 175,000 were impacted across various districts. More than 9,000 individuals were evacuated from their homes and were living in temporary shelters. The displaced population faced numerous challenges, including limited access to clean water, food, and medical care.
Climate change emerged as a significant contributor to the increasing frequency and severity of flooding in Sri Lanka. Located in the Indian Ocean, we are particularly vulnerable to climate-related disasters due to its geographical and climatic conditions.
Sri Lanka experiences two primary monsoon seasons—the southwest monsoon from May to September and the northeast monsoon from October to February. These seasonal rains, which are crucial for agriculture and water resources, are now becoming increasingly unpredictable and intense due to climate change. This section explores the historical context, present impacts, and the potential future threats posed by climate change.
Historical Context
Historically, Sri Lanka has experienced periodic flooding during the monsoon seasons. However, the frequency and intensity of these floods have escalated over the past few decades. Data from the Sri Lanka Meteorological Department indicates that the average annual rainfall has increased by approximately 7% over the past century. The Intergovernmental Panel on Climate Change (IPCC) has also noted a rise in extreme weather events in South Asia, including Sri Lanka, attributing this trend to global warming.
For instance, the floods of May 2017 were among the worst in recent history, resulting in over 200 fatalities and affecting more than 600,000 people. This event underscored the growing threat of climate change, as it was preceded by an extended drought, highlighting the erratic nature of weather patterns. The 2016 floods also caused significant damage, with nearly 500,000 people affected and widespread destruction of infrastructure.
Intensified Weather Patterns
Global warming has led to more erratic and extreme weather patterns. The warmer atmosphere holds more moisture, which results in heavier and more frequent rainfall events. This phenomenon is evident in the recent storms that have brought unprecedented amounts of rain in short periods. For example, the storm "Tauktae" in May 2024 caused some regions to receive over 250mm of rain within 24 hours, overwhelming both natural and man-made drainage systems.
The data reveals a worrying trend: the number of extreme rainfall events has increased by about 20% in the past decade. These events are characterized by high-intensity, short-duration rainfall that leads to flash floods. The increase in sea surface temperatures around Sri Lanka also contributes to these extreme weather events, as warmer oceans provide more energy for storm development.
Deforestation and Urbanization
Deforestation and unplanned urban development have significantly exacerbated the flooding issue in Sri Lanka. Forests play a crucial role in absorbing rainwater and reducing surface runoff. However, Sri Lanka has lost a considerable portion of its forest cover over the past several decades due to illegal logging, agricultural expansion, and infrastructure development. Between 1990 and 2020, the country lost approximately 30% of its forest cover, according to the Food and Agriculture Organization (FAO).
This reduction in forested areas has diminished the land's natural ability to absorb rainwater, leading to increased surface runoff and a higher likelihood of floods. Urban areas, with their impermeable surfaces such as concrete and asphalt, contribute further to rapid water runoff. The rapid expansion of urban areas, often without adequate drainage infrastructure, has strained the existing systems, leading to frequent urban flooding.
For instance, the Colombo Metropolitan Region, which has seen rapid urbanization, frequently experiences flash floods even with moderate rainfall. The inadequacy of the drainage infrastructure, combined with the loss of natural wetlands and green spaces, has made the city particularly vulnerable to flooding.
Topographical Challenges
Sri Lanka's diverse topography, with its mountainous regions and low-lying coastal plains, naturally predisposes certain areas to flooding. The central highlands, where many rivers originate, can experience rapid swelling of rivers during heavy rains, leading to downstream flooding. Rivers such as the Kelani Ganga, Kalu Ganga, Gin Ganga, and Deduru Oya are prone to overflowing, affecting the densely populated areas along their banks.
The country's topographical features also include numerous river basins that are susceptible to flash floods. The low-lying coastal areas, particularly in the southwestern region, are at risk due to sea-level rise and storm surges, which can exacerbate inland flooding. The lack of adequate flood protection infrastructure, such as dams, levees, and proper drainage systems, further compounds the problem.
The 2018 floods in Ratnapura district, a region with significant topographical variations, highlighted these challenges. The area experienced severe landslides and flooding, which were attributed to the steep terrain and intense rainfall. The floods caused extensive damage to homes and infrastructure, and the response efforts were hampered by the difficult terrain.
Future Threats and Necessary Actions
The current flood crisis is a very important reminder of the urgent need for effective climate adaptation and disaster management strategies. The Sri Lanka Meteorological Department has forecasted continued adverse weather conditions, including more heavy rains and strong winds, particularly in the Eastern and Uva provinces. Without significant intervention, these climate-induced disasters will become more frequent and severe, threatening lives, property, and the country's economy.
Building Resilience
To mitigate future risks, Sri Lanka must prioritize building resilience against climate change. This includes enhancing early warning systems, improving flood defenses, and investing in sustainable urban planning. Reforestation and the preservation of natural habitats are essential to restore the land's capacity to absorb rainwater.
Enhancing early warning systems involves improving weather forecasting capabilities and ensuring timely dissemination of information to the public. The integration of advanced technologies such as remote sensing and GIS (Geographic Information Systems) can enhance the accuracy of flood predictions and aid in better preparedness.
Improving flood defenses requires significant investment in infrastructure. This includes the construction of dams, levees, and floodwalls, as well as the rehabilitation of existing structures. Proper maintenance of drainage systems and the creation of retention basins can help manage excess water during heavy rains.
Sustainable urban planning is critical to address the challenges posed by rapid urbanization. This involves incorporating green infrastructure, such as parks, wetlands, and permeable surfaces, into city planning to enhance water absorption and reduce runoff. Additionally, implementing zoning regulations that restrict construction in flood-prone areas can mitigate the risk of flood damage.
The recent devastating floods have highlighted the pressing need for Sri Lanka to adopt comprehensive climate adaptation strategies. With over 85,000 people affected, 17 lives lost, and significant infrastructure damage, the stakes have never been higher. As we face continuous flood warnings and increasingly unpredictable weather patterns, the question remains: will Sri Lanka take the necessary steps to fortify itself against future climate-induced disasters, or will these catastrophic events continue to escalate, pushing the country to the brink? Only time will tell, but the urgency for action has never been clearer.