TNR News Network
Shimla:
Himachal Pradesh is witnessing a disturbing surge in cloudburst incidents, with over 50 such events recorded in this year’s monsoon season alone. The increasing frequency of intense rainfall, flashfloods and landslides has raised serious concerns among scientists and disaster management experts.
According to the Himachal Pradesh State Disaster Management Authority, since June, the state has seen over cloudbursts and more than 90 flashflood events. The number of cloudbursts, once rare and confined to higher altitudes, has now become a frequent occurrence even in lower and more populated regions.
Experts from IIT-Roorkee, Wadia Institute of Himalayan Geology in Dehradun and other earth science institutions have attributed this growing trend to climate change, unchecked construction and changes in Himalayan geography due to glacier melt and rising temperatures.
Climate change, human activity fuelling crisis
Over the past 30 years, the frequency of extreme rainfall events in the Himalayas has increased by nearly 200 per cent, according to recent scientific studies. These events are not only more common but also far more intense.
An environmentalist explains that glacier lakes — formed as Himalayan glaciers melt faster due to global warming — are now acting as ticking time bombs. During heavy rainfall, these glacial lakes can overflow or burst their natural embankments, triggering cloudburst-like flooding. Without proper monitoring, such lakes pose a serious threat to downstream villages and towns.
Adding to the vulnerability are the growing number of hydropower projects, dams and tunnels being constructed across the state. A hydroelectric expert warns that these projects are altering local weather patterns by increasing atmospheric moisture through excessive evaporation from large reservoirs. This raises the risk of localised heavy rainfall.
Roads and tunnels carved through unstable mountain terrain further destabilise the geology, making the hills more prone to landslides and flashfloods following intense rainfall.
From remote peaks to urban slopes: Cloudbursts reach new areas
Traditionally, cloudbursts were limited to remote, high-altitude regions, but now they are striking closer to human settlements. A retired engineer notes that rapid urbanisation and loss of forest cover have destroyed natural water drainage systems. In many areas, unplanned concrete construction blocks water flow, leading to pooling and sudden runoff, mimicking the impact of cloudbursts.
These urban modifications to the landscape have made it easier for large volumes of rainwater to accumulate and surge downhill rapidly, causing destruction similar to that of a cloudburst — even when the actual rainfall volume may not qualify as one by traditional definitions.
Cloudbursts typically involve 100 mm or more of rain in an hour over a small area. The phenomenon occurs when heavily moisture-laden clouds become trapped against mountains, rapidly releasing massive amounts of rain due to high humidity and temperature variations. They often occur in the afternoon or night, when atmospheric moisture peaks.
Experts say risk remains, call for vigilance and policy action
Meteorologists warn that the threat is far from over. Dr Manmohan Singh, former director of the Meteorological Centre in Shimla and Chandigarh, explains that global warming has significantly increased moisture content in the atmosphere. Massive cumulonimbus clouds —linked to thunderstorms, hail and high winds — are now forming more frequently in the Himalayan region.
He adds that intense, short bursts of rain are replacing the traditional pattern of steady monsoon showers. “What used to be a month’s worth of rain is now falling in a single day,” he says, exacerbating erosion, landslides, and flooding.
