Glacial Lake Outburst Floods (GLOFs) pose significant dangers and have a range of negative impacts. One of the most alarming consequences is the loss of human lives. The devastating event that occurred in Kedarnath in 2013 is a reminder of the destructive potential of GLOFs. The cloudburst triggered an outburst of the Chorabari Glacier lake, resulting in flash floods that tragically claimed the lives of over 6,000 individuals. This catastrophic incident underscores the urgent need to address the risks associated with glacial lakes.
In addition to the loss of lives, GLOFs also pose threats to vital infrastructure, such as hydropower projects. The sudden release of water from a glacial lake can cause severe damage to these facilities, leading to significant economic losses and disruptions in power supply. Moreover, the destructive power of GLOFs extends to properties in the affected areas. Flash floods resulting from glacial lake outbursts can sweep away homes, businesses, and other structures, causing extensive damage and displacing communities.
Furthermore, the health of individuals is profoundly impacted by GLOFs. The torrential floods can contaminate water sources, leading to the spread of waterborne diseases and posing severe risks to public health. The destruction of infrastructure, including healthcare facilities, exacerbates the challenges faced in providing timely medical assistance and relief efforts to affected populations.
Reflecting on the recent event in Sikkim on October 4th, 2023, it is crucial to determine whether it qualifies as a GLOF.
What exactly is a GLOF?
According to the definition provided by the International Centre for Integrated Mountain Development (ICIMOD), a GLOF involves the sudden release of water from a glacier-fed lake. In the case of South Lhonak Lake, there was indeed a breach of water from the lake, although the boundaries of the lake, known as the moraine dam, did not break entirely. Nevertheless, this breach implies that the dam, which held the water, was triggered by external factors, causing the water to breach its own barrier. This occurrence raises concerns about the potential increase in water levels in the lake in the coming years. It is worth noting that similar occurrences, known as Jokulhaups, are more commonly observed in Iceland and, are also considered a type of GLOF.
What triggered that GLOF at South Lhonak Lake?
To determine the trigger for the GLOF at South Lhonak Lake, satellite imagery provides valuable insights. The images confirm the presence of a landslide-like thing (we will call it a landslide for common understanding) in the northwestern part of the lake. The Department of Science and Technology (DST) in Sikkim, in one of its recent press releases, interpreted this as the detachment of a wall from the lateral moraine. Consequently, it is evident that the abrupt release of water was not caused by a cloudburst, but rather by a landslide. However, there was significant rainfall in the last couple of days at the lake area before the event which was confirmed by IMD. 3D rendering of the area using Sentinel 2 Satellite data clearly indicates the location of the landslide. The imagery also reveals the accumulation of ice after the water levels in the lake decreased.
Post Event Image (7th October)
Pre-event Image (26th September).
Post Event Image (7th October)
Pre-event image (26th September).
How intense the water flow was?
The intensity of the water flow at the onset of the event was indeed significant. This can be observed from the Satellite data, particularly in the first image given below where there is visible evidence of muddy soil/sand deposition right from the start. The presence of such sedimentation indicates that the water flow possessed considerable force and velocity from the initial stages of the release.
Furthermore, the satellite data provides valuable insights into the intensity of the water flow within the channel. Based on this data, it can be inferred that the water must have been flowing at a substantially high rate following the release. This suggests that the water flow was intense throughout the course of the event.
In light of these observations, it is inaccurate to claim that the water flow was not intense from the beginning which many people claimed earlier. On the contrary, the evidence points to a strong and forceful water flow right from the initial moments of the release.
Post Event Image (7th October)
Pre-event image (26th September).
Did Chungthang dam intensify the floods?
The question of whether the Chungthang dam was responsible for increasing the intensity of the damage is indeed complex. While the dam itself was completely damaged, it can be argued that its destruction slightly intensified the floods in the Chungthang region. There are a few reasons to support this argument.
Firstly, the gates of the dam were not opened, resulting in increased pressure on the structure. The failure to release water through the gates added to the overall stress on the dam, potentially contributing to its ultimate failure. The added pressure caused by the closed gates could have exacerbated the intensity of the floods in the surrounding area.
In addition, the satellite imagery provides some preliminary evidence to support the notion of increased damage due to the dam’s failure. From the images taken by Planet Labs, it is visible that the dam reservoir had an extra spill-over of debris and sediments, extending up to 1.2 km from the dam. While this observation is based on satellite data and not on hydrodynamic or hydrological analysis, it suggests that the destruction of the dam had an impact on the extent of the flooding in the region. The polyline marked on the images below indicates the extra spillover.
Post Event (12th October)
Pre Event (29th September)
It is important to note that further investigation and comprehensive analysis would be required to fully understand the role of the Chungthang Dam in the intensity of the damage caused by the floods. The preliminary observations from the available satellite data, however, suggest that the dam’s failure likely had at least a slight intensifying effect on the floods in the Chungthang region, though not on maximum as flow itself was intense from the beginning.
Three major reasons identified for the damage of Chungthang Dam.
- Overloading: A significant release of water from South Lhonak lake causing excessive flow supported by gravity led water to accumulate behind the dam. Dam was unable to handle this increased flow putting excessive pressure on the structure that led to its failure.
- Human Error: Human error during operation and maintenance activities could also have led to dam failure. Improper operation, failure to follow established protocols, or inadequate response to warning signs, all factors jointly contributed to the failure of the hydropower dam.
- Poor Design or Construction and Structural Weakness of dam: Inadequate design or construction practices would have also contributed to the dam. Flaws in the design phase, such as miscalculations of water flow or insufficient consideration of geological factors, could have led to structural instability.
While it’s true that not all dams are created equal and there have been instances where inadequately designed or maintained dams have faced challenges, a well-constructed and properly maintained dam can play a pivotal role in controlling floods. Dams, when engineered with precision, serve as vital tools in managing water resources, preventing the devastation caused by floods, and ensuring a stable supply of water for various purposes.
Dikchu Dam and its hero saved lives.
The case of the Dikchu Dam is an example of the positive impact such structures can have on local communities. On the 4th of October, the Dikchu Dam demonstrated its capacity to hold a substantial volume of water. This reservoir not only showcased its ability to control water but also safeguarded the lives and properties of those residing in areas such as Singtam, Majhitar, Rangpo, and Teesta Bazar. By effectively regulating the flow of water dam exemplified how good engineering and maintenance practices can transform dams into essential guardians.
Also, salute to Mr. Dawa Lepcha who sacrificed his life while opening the gates of the dam.
Therefore, it is imperative to recognize the potential of dams when they are built and managed correctly, as they stand as robust defenses against the forces of nature, enhancing both public safety and environmental stability.
Below is the image showing how Dikchu dam held the water and saved lives (Image from the social media).
Who is responsible for the disaster?
The easy answer for this is all of us, let’s understand how.
The responsibility for the disaster of global warming and its associated consequences is indeed a shared burden. It is a collective issue that involves the actions and choices of individuals, communities, industries, and nations around the world.
Individually, our daily activities, such as driving cars, using energy, and consuming products, contribute to the emission of greenhouse gases. Even seemingly unrelated actions, like the choices we make as consumers, can indirectly impact the environment. Production of food, medicines, alcohol, and other goods in factories significantly contributes to pollution, adding to the overall environmental strain.
Do you know that 14.5% of all human-caused greenhouse gas emissions are attributable to livestock farming? This means eating meat or milk also contributes to climate change.
So, let’s learn first.
On a larger scale, countries play a crucial role. The top three polluters—China, the United States of America, and India—have substantial carbon footprints due to their industrial activities, energy consumption, and population size. However, it’s important to note that these nations are also taking steps to address environmental issues, and efforts are being made globally to mitigate the impact of climate change.
Is there a solution to global warming?
Certainly, addressing global warming demands a coordinated effort on a global scale. It’s not a challenge that can be tackled in isolation; it necessitates the commitment of every individual and nation worldwide. The idea that the environment can be saved if some people pollute while others do not is a fallacy. Every corner of the world, from bustling cities to remote villages, plays a role in this shared responsibility.
Take the case of Sikkim as an example. While it’s essential for Sikkim to focus on its development, it’s equally vital for the state to prioritize its ecosystem. Being susceptible to various disasters due to its geographical location, Sikkim must strike a balance between progress and environmental conservation. However, this responsibility does not fall solely on Sikkim’s shoulders. Every person, community, and nation must recognize the detrimental effects of climate change and actively contribute to the solution.
At the core of this effort lies awareness. Creating widespread awareness about the urgent need for environmental preservation is paramount. People need to comprehend the gravity of the situation, realizing that their actions matter. One of the most straightforward yet impactful solutions is to advocate for the preservation of trees and the expansion of green cover. Trees act as nature’s carbon absorbers, pulling harmful gases from the atmosphere and helping to cool the Earth. Encouraging afforestation and discouraging deforestation are fundamental steps.
It’s crucial to grasp that the consequences of climate change are far-reaching and diverse. Beyond the obvious effects like the melting of ice and the formation of glacial lakes, even subtle shifts in our surroundings, such as the migration of animals like monkeys due to rising temperatures, underscore the intricate web of changes caused by climate change.
What is climate emergency and why do we need to act now?
A climate emergency is a situation in which there is a drastic and urgent need to address climate change due to its severe and immediate impacts on the environment, ecosystems, societies, and economies. It signifies a critical state where the Earth’s climate system is rapidly changing, leading to extreme weather events, rising sea levels, loss of biodiversity, and disruptions in agriculture and water resources, among other challenges. So yes, we are in the climate emergency.
We need to act now for several crucial reasons mentioned below so that we can reverse many changes in this century itself, otherwise, we will suffer for sure but future generations will suffer more:
- Rapid Warming: The Earth’s average temperature is rising at an alarming rate due to human-induced activities such as burning fossil fuels, deforestation, and industrial processes. This warming contributes to a multitude of adverse effects, including heatwaves, droughts, and more intense storms.
- Melting Polar and Non-Polar Ice: The Arctic, Antarctic, and Himalayan regions are experiencing rapid melting of glaciers and ice sheets. This contributes to rising sea levels and, formation of glacial lakes posing a significant threat to communities and low-lying lands.
- Extreme Weather Events: Climate change intensifies extreme weather events, leading to more frequent and severe hurricanes, floods, wildfires, and heatwaves. These events cause widespread destruction, displacement of communities, and loss of lives.
- Loss of Biodiversity: Climate change threatens ecosystems and biodiversity. Many plant and animal species are struggling to adapt to changing temperatures, leading to habitat loss and potential extinction.
- Impact on Agriculture: Changes in temperature and precipitation patterns affect crop yields and food production. This can lead to food shortages and increase the risk of hunger in vulnerable communities.
- Social and Economic Impacts: Climate change exacerbates existing social and economic inequalities. Vulnerable populations, including low-income communities and developing nations, are disproportionately affected by climate-related disasters and challenges.
- Tipping Points: There are critical thresholds or tipping points in the climate system, beyond which certain impacts become irreversible. Acting now can help prevent crossing these points and facing catastrophic consequences.
- Global Cooperation: Climate change is a global issue that requires collaborative efforts from nations, industries, and individuals worldwide. Acting promptly allows us to work together to find solutions and implement policies that can mitigate the impacts of climate change.