The short version
- Built-up land in high-risk Himalayan zones grew by roughly 45 percent between 2016 and 2023, with areas near glacial lakes seeing a nearly 78 percent increase.
- At least 300,000 people now reside in paths of potential disaster across parts of Nepal, India, and Tibet, though the actual number may be higher due to limited study scope.
- Warming temperatures are accelerating ice melt and expanding glacial lakes, increasing the frequency and severity of floods that overwhelm existing infrastructure and safety buffers.
A surge in construction across parts of the Himalayas has placed approximately 300,000 people in direct proximity to potential natural disasters, according to a new peer-reviewed study. The research highlights a troubling convergence of rapid urbanization and climate-driven environmental instability in northern Nepal, southeastern Tibet, and India’s Uttarakhand region. Between 2016 and 2023, the amount of developed land in high-risk zones expanded by about 45 percent. In areas specifically threatened by flooding from glacial lakes, development accelerated even more sharply, rising by nearly 78 percent over the same seven-year period.
The study, published in Scientific Reports, was conducted by a team of nine researchers from the United Kingdom, Nepal, and India. They analyzed territories up to 50 kilometers downstream from Himalayan rivers and examined the surroundings of roughly 1,360 glacial lakes. The findings indicate significant growth in tourism facilities, infrastructure projects, and real estate developments within these vulnerable corridors. However, the authors caution that the true number of people at risk is likely much higher, as their analysis focused on specific territories and did not include neighboring areas that face similar geological and climatic threats.
The timing of this research underscores its urgency. The study was completed before the devastating mass floods in August 2026, which killed more than 1,400 people and left thousands missing in Nepal. Since then, smaller but destructive incidents have continued to occur. In early October, flooding along the Budhi Gandaki river damaged hundreds of homes, destroyed five bridges, and resulted in several missing persons. These events illustrate the immediate danger posed by the region’s expanding footprint in unstable landscapes.
Pokhara, a major tourism hub at the foot of the Himalayas, exemplifies the challenges facing local authorities. The city has grown substantially over the past three decades to accommodate a massive influx of visitors. Mayor Dhana Raj Acharya noted that managing the risk posed by the Seti Gandaki River is a significant hurdle. Many older structures stand just five meters from riverbanks, despite new regulations requiring greater setbacks. The logistical difficulty of relocating these buildings and enforcing safety standards remains a critical unresolved issue for city planners.
Beyond urban centers, trekking regions such as the Annapurna circuit have seen a major increase in settlements along riverbanks. Local business owners report severe disruptions to their livelihoods. Phurpa Chhiring Lama, who operates a homestay in the area, described a sharp decline in occupancy during peak season due to recent disasters. He noted that after four decades in the industry, he had never witnessed such destructive events. Similarly, Krishna Gauchan, whose hotel is near the glacier-fed Modi river, expressed constant fear of potential floods triggered by glacier collapse or bursting glacial lakes.
Experts suggest that tourism promotion often overlooks these inherent risks. Khagendra Poudel, a geographer at Tribhuvan University, indicated that investors frequently market destinations without adequately factoring in geological dangers. This pattern mirrors developments in north India’s Himalayan valleys, which host major religious pilgrimages. Laxman Subedi, president of the Hotel Association Pokhara, admitted that tourism businesses have expanded haphazardly and without proper planning. He emphasized that disaster preparedness efforts often come too late, once infrastructure is already entrenched in hazardous zones.
The threat extends beyond tourism to energy infrastructure. Regions surrounding the Bhotekoshi and Trishuli rivers have experienced a significant rise in hydropower plant construction. C Scott Watson, a glaciologist at the University of Leeds and lead author of the study, warned that development decisions made today will shape disaster risk for decades. As river valleys become increasingly populated, the consequences of future floods or landslides could be far more severe than current models predict.
The underlying driver of these risks is rapid warming in the Himalayan region, which scientists say is occurring at twice the global average rate. This accelerated heating is melting glaciers, icefields, and snowpacks, while also thawing permafrost that normally stabilizes mountain slopes. The resulting instability makes the terrain more susceptible to earthquakes and landslides. Additionally, rising temperatures are causing glacial lakes to expand and eventually burst, leading to deadly floods. Nepal has documented around 30 such events since 1940, a trend expected to continue as climate impacts intensify.
Current risk assessments may underestimate the danger faced by communities. The study categorized buildings at risk as those within 50 vertical meters of a river or glacial lake surface. However, during the catastrophic August flooding, residents in Rasuwa district reported that river levels rose by up to 70 meters in some locations. This means that even structures situated relatively far from riverbanks were inundated and buried by debris. The discrepancy between modeled risk zones and actual flood behavior suggests that safety buffers may be insufficient against extreme events.
As the region grapples with these challenges, the intersection of climate change and unchecked development presents a complex policy dilemma. While economic growth through tourism and energy production is a priority for local governments, the long-term sustainability of building in high-risk zones remains questionable. Without stricter enforcement of zoning laws and better integration of climate risk into planning decisions, the number of people exposed to potential disasters is likely to continue rising.
Sources behind this briefing
Go to the original reporting
- BBC Science & Environment↗Building boom puts 300,000 people in the path of potential Himalayan disasters
