Hindu Kush Himalayas at greater risk of landslides, floods this monsoon: Report

There is a high risk of flash floods, landslides and glacial lake outburst floods in the Hindu Kush Himalaya (HKH) region this monsoon season owing to forecasts of above-average rainfall, experts from an intergovernmental organisation said on Wednesday.

The International Centre for Integrated Mountain Development (ICIMOD) also said temperatures across the HKH region are expected to be up to 2ºC higher than normal during the monsoon.

In India, as per the ICIMOD website, the HKH covers the entire territory of 11 mountain states — Assam, Uttarakhand, Himachal Pradesh, Manipur, Jammu & Kashmir (Union Territory), Meghalaya, Mizoram, Nagaland, Sikkim, Tripura, Arunachal Pradesh — and Darjeeling district of West Bengal.

It is also the source of 10 major Asian river systems — Amu Darya, Indus, Ganges, Brahmaputra (Yarlungtsanpo), Irrawaddy, Salween (Nu), Mekong (Lancang), Yangtse (Jinsha), Yellow River (Huanghe), and Tarim (Dayan). Apart from providing livelihoods to around 240 million people, the basins of these rivers also provide water to 1.9 billion people, or a fourth of the world’s population.

"Above-normal precipitation between June and September, as predicted by the various meteorological agencies, is fraught with the high risks of disastrous flash floods and landslides along the mountainous terrains," ICIMOD said in a report.

It added that rising temperatures in the HKH can speed up the melting of glaciers and snow, leading to short-term increases in river flows and a higher risk of glacial lake outburst floods (GLOFs). Warmer temperatures also reduce snow build-up, which threatens the long-term water supply for millions of people living downstream.

The HKH region is very sensitive to the monsoon, especially the systems linked to the Indian Ocean and southern Asia. Rainfall between June and September is the main source of water for the region. It has a major effect on river systems that support nearly 2 billion people.

While the monsoon is crucial for refilling these rivers, the danger from water-related disasters, such as floods, landslides, storms, heatwaves, wildfires, droughts and GLOFs, is increasing due to the worsening impacts of climate change. For example, more than 72.5 per cent of flood events in the region between 1980 and 2024 happened during the monsoon season.

"The forecasts we have studied are unanimous in predicting a hotter monsoon across the entire HKH, with a trend towards higher-than-normal rainfall in major parts of HKH," said Arun Bhakta Shrestha, senior advisor at ICIMOD.

He said higher temperatures and more extreme rainfall increase the risk of water-related disasters such as floods, landslides and debris flows and can have long-term effects on glaciers, snow and frozen ground.

"Lower rainfall, meanwhile, particularly in water-stressed countries such as Afghanistan, may pose risks to food and water security in a country with already extraordinarily high levels of malnutrition," Shrestha said.

Saswata Sanyal, manager of ICIMOD’s disaster risk reduction work, said, "Given the extremely high exposure and risks in our region, we urgently need impact-based early warning systems adopted at scale and for government and donor support to build up disaster preparedness to increase."

With PTI inputs