Over the years, India has experienced numerous devastating cloudbursts. One of the most devastating incidents took place in 2013 in Uttarakhand, a northern state of India with a significant portion of its territory located in the Himalayan mountain range. This catastrophic cloudburst triggered flash floods and landslides, resulting in the loss of thousands of lives, extensive damage to infrastructure, and the disruption of livelihoods. In another instance, in 2021, Himachal Pradesh, a state in the western Himalayas, faced a cloudburst that wreaked havoc in the tribal district of Lahaul and Spiti. The sudden deluge caused fatalities, inflicted extensive property damage, and severed road connections.
Now, within the last week itself, the Himalayan regions of India experienced various cloudburst events in Shimla, Kinnaur and Kullu districts of Himachal Pradesh, Srinagar and Kulgam district of Jammu & Kashmir, and Leh region of Ladakh. While cloudbursts in themselves are no strange events in the Himalayan regions of India, what concerns the experts is the frequency and intensity with which they are now occurring in the region, leaving climate change as a major catalyst.
A cloudburst takes the phrase “raining cats and dogs” to a whole new level. So, the word “cloudburst” doesn’t literally mean that some cloud somewhere actually burst open like a balloon. Rather, it means that there has been a sudden spurt of extreme rainfall over a small local region within a short span of time. Therefore, the word “cloudburst” is used to convey the explosive and overwhelming nature of the phenomenon, fittingly describing the dramatic and significant impacts of the event.
The Indian Meteorological Department (IMD) defines a cloudburst as 100 millimetres of rainfall pouring down in just an hour, which is concentrated within a radius of around 10 square kilometres. And because of this crazy intensity, the poor drainage systems can’t handle all that water, leading to flash floods and havoc in the affected areas.
Cloudbursts often occur in the Himalayan regions because of its unique topography. When the moisture-laden winds from over the surface of the Indian Ocean entering the subcontinent during monsoon, encounter the steep slopes of these towering peaks, they are forced to rise up rapidly. This ascension leads to condensation, resulting in cloud formation. The clouds thus formed are known as cumulus clouds, which are the fluffy looking cauliflower-shaped clouds indicating pleasant weather conditions.
But, as the updraft continues against these gigantic mountains, the cumulus clouds keep growing vertically to become giant tall cumulonimbus clouds which can grow up to 12 to 15 kilometres in height. These tropospheric clouds can carry the energy of up to 10 Hiroshima-sized atom bombs, as per the Meteorological Office of the United Kingdoms.
As the water droplets within these clouds keep getting bigger and newer ones keep forming along with, the cloud ultimately loses its capacity to hold them together resulting in cloudburst. And since the mountains provide a longer vertical traction, these clouds form more often in these regions. To make things worse, rapid urbanisation and climate change can exacerbate cloudbursts in urban areas. As per the Clausius Clapeyron relationship, a 1o Celsius increase in temperature can increase the air’s capacity to hold moisture by 7 to 10 per cent. On the other hand, concrete jungles with limited green spaces can alter local weather patterns and create “urban heat islands,” intensifying rainfall.
Flash Floods: The sudden and intense downpour overwhelms drainage systems, leading to flash floods that can inundate cities and towns. Flash floods can result in loss of life, damage to property, and disruption of essential services.
Landslides: Cloudbursts in hilly regions trigger landslides, as the water-saturated soil becomes unstable and slides downhill. Landslides can block roads, damage infrastructure, and pose serious threats to human settlements.
Agricultural Losses: While rainfall is generally beneficial for agriculture, cloudbursts can be detrimental. Excessive rainfall in a short time can flood fields, destroy crops, and result in significant economic losses for farmers.
Ecological Impact: Cloudbursts can disturb fragile ecosystems, causing soil erosion, altering river courses, and impacting wildlife habitats. The sudden surge of water can also lead to water pollution, affecting aquatic life.
To better prepare for cloudbursts, India can implement a comprehensive and proactive approach. Firstly, strengthening early warning systems through advanced weather monitoring technology and radar systems is crucial. The indigenously built X-Band Doppler Weather Radars are a good step in this direction as they will enable timely alerts to vulnerable communities in the Himalayan region, allowing them to take necessary precautions and evacuate if needed.
Additionally, reinforcing critical infrastructure, such as drainage systems and bridges, can minimise damage and disruption. Encouraging afforestation and watershed management practices will help retain water during heavy rainfall, reducing the risk of flash floods and soil erosion. Furthermore, establishing flood monitoring systems and pre-positioning rescue and relief resources will aid in swift response during cloudburst emergencies. By integrating climate change adaptation strategies into disaster management planning and promoting international cooperation for data sharing and disaster strategies, India can enhance its preparedness and resilience to cloudbursts, ensuring the safety and well-being of its communities.