At least 300,000 people across parts of the Himalayan region could be living in areas threatened by potentially devastating natural disasters as rapid construction pushes more settlements towards dangerous rivers and glacial lakes, a new study has found.
Researchers discovered that built-up land in high-risk areas of northern Nepal, south-eastern Tibet and India’s Uttarakhand state increased by about 45% between 2016 and 2023.
Development in areas particularly exposed to flooding from glacial lakes grew even faster, rising by almost 78% over the same period, according to the peer-reviewed study published in Scientific Reports.
The researchers warned that the actual number of people exposed to danger could be considerably higher because their analysis covered only a specific territory, excluding neighbouring areas facing similar threats.
The study was conducted before devastating floods struck Nepal in August, killing more than 1,400 people and leaving thousands missing.
Further flooding along the Budhi Gandaki River on 11 October damaged 200 houses, swept away five bridges and left five people missing.
The nine researchers from the UK, Nepal and India examined settlements along Himalayan rivers, covering areas up to 50km downstream, as well as approximately 1,360 glacial lakes.
They identified substantial development in potentially dangerous locations, driven by expanding tourism facilities, infrastructure projects and real estate construction.
The impact is particularly visible in Pokhara, a major tourism destination at the foot of the Himalayas that has expanded considerably over the past 30 years to accommodate growing visitor numbers.
Mayor Dhana Raj Acharya said managing the danger posed by the Seti Gandaki River, which originates in the Annapurna mountain range and flows through the city, remains a major challenge.
According to Acharya, many older buildings stand just five metres from riverbanks, despite newer regulations requiring greater separation.
“Where we move them, and how we do that, is the real challenge.
Further north, the internationally recognised Annapurna trekking region has also experienced considerable growth in settlements along rivers, with some communities recently affected by floods and landslides.
Phurpa Chhiring Lama, who operates a homestay in the region, said the disasters had severely affected his business.
Although all 20 rooms would normally be occupied during the peak trekking season, only five are currently booked.
“We have been doing this business for more than 40 years, but we’ve never seen this kind of disaster.”
Hotel owner Krishna Gauchan, whose property stands near the glacier-fed Modi River, also expressed concern about the possibility of another disaster. “This river can flood if the glacier collapses or if the glacial lake bursts out and we are living in constant fear.”
Khagendra Poudel, a geographer at a local campus of Tribhuvan University, suggested that some tourism investors were promoting destinations without adequately considering the dangers.
He said similar development patterns were occurring in Himalayan valleys in northern India, where major religious pilgrimages attract large numbers of visitors.
President of the Hotel Association Pokhara, Laxman Subedi, acknowledged that tourism businesses had expanded without proper planning and that destinations had been promoted without sufficient consideration of safety. “By the time disasters hit, it is too late, as a professional body we are trying to create awareness among tourism entrepreneurs and investors.”
Construction is not limited to tourism facilities. Areas surrounding the Bhotekoshi and Trishuli rivers have also experienced significant growth in hydropower projects.
Lead researcher C Scott Watson, a glaciologist at the University of Leeds, warned that current development decisions could have consequences for generations. “As river valleys become increasingly populated, development decisions being made today will shape disaster risk for decades to come.”
Researchers classified buildings as exposed to danger if they stood within 50 vertical metres of a river or glacial lake’s surface.
But the actual threat could extend considerably further.
During catastrophic flooding on 26 August, residents of Nepal’s Rasuwa district reported that river levels rose by as much as 70 metres in some locations, destroying buildings situated relatively far from the riverbanks and burying others beneath mud and debris.
Scientists say warming across the Himalayan region is occurring at approximately twice the global rate, accelerating the melting of glaciers, icefields, snowpacks and permanently frozen ground.
These changes can destabilise mountain slopes, which are also frequently affected by earthquakes, increasing the possibility of destructive landslides and flooding downstream.
Melting glaciers are also filling and expanding glacial lakes, raising the danger of sudden outburst floods.
Nepal alone has documented approximately 30 such incidents since 1940.
Rising temperatures are creating additional dangers by allowing rainfall to reach higher altitudes that previously experienced mainly snowfall. This can trigger slope failures, rockfalls and icefalls.
Nepal’s Prime Minister Balendra Shah recently raised the issue at the United Nations General Assembly, arguing that his country was bearing a disproportionate burden from climate change.
He said Nepal was paying a “colossal price” for a problem it had not created. “Every major disaster threatens to erase years of development. And it forces a poor country to borrow money to repair damage it did not cause.”
Alton Byers, a mountain geographer at the University of Colorado who was not involved in the research, said the findings should provide a basis for developing more effective early-warning systems and other protective measures.
But experts and campaigners warned that weak enforcement of construction regulations remained a major obstacle.
Professor Surya Raj Acharya, an urban planning expert and registrar at the University of Nepal, said roads, hotels, hydropower facilities and market towns had expanded along low-lying river valleys because the land was accessible and easier to develop.
He argued that developers frequently disregarded safety measures, including restrictions on building close to riverbanks.
“A fragile ecosystem like the Himalaya demands stricter planning and building regulations than elsewhere, yet these rules have been weak and poorly enforced.”
Nepalese authorities say they are introducing measures to address the growing danger.
According to the country’s national disaster agency, settlements within 15 metres of riverbanks along the recently devastated Rasuwa-Bhotekoshi corridor will soon be prohibited.
Similar restrictions are being prepared for other river corridors.
The agency’s chief executive, Dharam Raj Uprety, acknowledged that implementing the measures would be difficult because many residents have longstanding emotional attachments to their land and properties. “It is a challenging job because people in many places have sentimental attachments with their land and property but we cannot ignore the increasing risks.”
Across the border in India’s Uttarakhand state, environmental activist Anoop Nautiyal alleged that tourism limits and environmental regulations had repeatedly been bypassed in pursuit of economic growth.
Although zoning regulations prohibit construction too close to rivers, Nautiyal said enforcement remained inadequate. “You can see rampant construction all over.”
On 12 October, Uttarakhand’s government approved new floodplain zoning regulations intended to control land use and development.
According to the state cabinet, the measures are designed to protect lives, property and essential infrastructure from flooding while preserving the natural movement of floodwaters.
Basanta Raj Adhikari, director of the Centre for Disaster Studies at Tribhuvan University, warned that completely eliminating the region’s natural disaster risks would be impossible.
He suggested introducing insurance classifications based on geographical risk as another way to encourage safer construction.
Under such a system, authorities would categorise locations as high, moderate or low risk, allowing insurance coverage to reflect the level of danger.
Adhikari believes this could encourage residents and developers to choose safer locations by offering better insurance protection for properties built in lower-risk areas.
Despite growing scientific warnings and repeated disasters, construction across the Himalayan region continues to expand.
Erizia Rubyjeana
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