September 8, 2026
Keshav Lall Maharjan
Vice president, Association of Regional Agricultural and Forestry Economics, Japan



I had intended to write my second report sooner, but I just haven’t been able to bring myself to do it. Lately, I’ve just been idly gathering information. Today, realizing I have to do something about it, I’m sitting down at my computer. There are several reasons why I’m not in the mood. First, I lack the knowledge to fully understand what has happened this time. Second, the scale of the disaster is simply too immense—the daily toll of casualties reported in the news keeps rising, the heartbreaking sight of bodies (including partial remains such as limbs or torsos), and the sight of people at morgues, rescue centers, and evacuation shelters, searching desperately for their families, relatives, and friends while struggling to cope with their grief. the activities of rescue teams working tirelessly around the clock to save lives and carry out rescue operations despite every obstacle; the disappointment felt by people—especially the bereaved families and relatives of the victims—that the results are not meeting their expectations; certain politicians attempting to exploit the situation for political gain; and the proliferation of inaccurate information on some social media platforms (including individuals using TikTok, X, etc.) that sensationalize the events—all of these factors had left me feeling deeply disheartened.

What Happened: the supplement
As mentioned previously, the weather forecast for the Rasuwa region on August 26 called for sunny skies followed by rain, and it appeared there had been no rain, just as on the previous day. However, shortly before 9:00 a.m., a flash flood suddenly surged forward with tremendous force. The image shows that torrential floodwater collided with the Chinese border checkpoint, creating a huge wave that, in the blink of an eye, engulfed the imposing, magnificent building, as well as dozens of parked buses and cars, and swept them away.” However, the above document does not fully and accurately explain the phenomenon. On August 27, I replied to an acquaintance who had contacted me out of concern for my safety: “It’s a flash flood, yet the water looks like sludge? I think there is much to learn about the Earth, the climate, and the geological strata of the Tibet and Himalayan regions.” In other words, the flash flood I saw in the images was different from the mudslides and muddy torrents I had previously experienced in India, Japan, Nepal, Bangladesh, and Bhutan. That flood, laden with debris, contained so much earth and rock that it could not be fully described simply as a mudslide or muddy torrent; it was essentially slurry or mudslurry itself, cascading down like a wall of water from a height of 10 meters—and in some places, as high as 30 meters—above the ground (the river’s surface). Last time, I described it as an “inland tsunami,” but Nepal’s Foreign Minister Mr. Kanal referred to it as a “Himalayan tsunami,” noting that it was a dramatic flow originating not from the sea but from the Himalayas. Viewed from above, the watershed between Raswagadi and Shabru Besi looks almost as if a thick cloud were flowing by. This is likely due to dust and water vapor rising from the forest. So, what exactly is the nature of this flood? There is certainly much to learn from it.

Experts both in Nepal and abroad have confirmed that this disaster was not caused by an earthquake, based on ground-based seismic waves, satellite imagery, photographs taken by drones, and observations from helicopters. According to the USGS (U.S. Geological Survey), at 8:37 a.m. Nepal time (10:52 a.m. China time) on that day, seismic waves equivalent to a 5.2-magnitude earthquake were detected along the Nepal-Tibet-China border. This was caused by a massive collapse of a glacier and bedrock on the northern slope of Mount Lantang Lirung near the border (according to experts at the University of Zurich in Switzerland, the bedrock collapsed first, followed by the glacier). The falling mass is said to have a vertical drop of approximately 1 km, a width of 600 m, and a thickness of 50 m, with a total weight estimated at 4.4 Mt (megatons). This glacier and bedrock fell into the Lhende River along the border; due to the pressure and heat generated, the glacier melted, the bedrock shattered and flowed downstream, and part of it was naturally dammed and then breached, surging with tremendous force into southern Nepal.

Nearly three hours later, seismic waves equivalent to a 4.2-magnitude earthquake were also recorded in the same area (though pinpointing the exact location is difficult due to the weak seismic waves), and this is also believed to have been caused by a collapse of the glacier and bedrock. In other words, there were not one but two collapses of the glacier and bedrock on this occasion. As the glacier melted, the water volume increased and the flow accelerated, eroding the mountains on both sides of the narrow river valley and rushing down rapidly while sweeping up debris. It traveled a distance of approximately 20 km—a vertical drop of over 3,300 m—from 5,140 m to the Kerung border post at 1,800 m, covering the distance in 7 minutes (at over 170 km/h), completely obliterating the Chinese checkpoint at the Kyirong/ Gyirong (Jilong-xian; Nepali: Kerung) border (see Photo 1 in Report 1). The Nepalese border checkpoint at Rasuwagadi was similarly swept away without a trace.

Within Nepal, the Lhende River becomes the Bhotekoshi and Trisuli Rivers as it flows southward; it eventually crosses the Nepal-India border and, in India, becomes the Gandak River. In the states of Uttar Pradesh and Bihar, it swells in size and becomes a major tributary of the Ganges River. The recent major flooding has been confirmed as extending to these regions of India.
The Bhotekoshi and Trisuli Rivers flow through narrow mountainous basins without losing any of their force, and their massive floodwaters sweep away not only the soil, rocks, and trees eroded from both banks—as is typical of turbulent rivers—but also villages, towns, roads, bridges, power plants, factories, warehouses, homes, schools, hospitals, cars, livestock sheds, farms, livestock, crops, and people—sweeping away everything in its path in the blink of an eye, while heavy debris is deposited here and there. In open areas, the rivers, which are typically several dozen meters wide, flooded over an area more than 1 km wide, engulfing towns and other settlements. Local residents report that where the floodwaters slowed, large amounts of debris were deposited, raising the riverbed by more than 10 meters. This phenomenon is particularly evident in the towns of Betrawati, Trisuli, Bidur, Debghat, and Galchi.
This massive flood was caused by multiple factors, and the nature of the flooding (water volume, what was swept away) and its characteristics (current, inundation, etc.) varied by region. In particular, the bazaars, homes, lodging facilities, and eateries along the rivers in Timle and Shabru Besi were completely swept away; thereafter, the floodwaters came to contain not only debris, mudslurry, and brush but also bridges, dams, buildings, vehicles, and people.

The International Centre for Integrated Mountain Development (ICIMOD), an international organization based in Kathmandu, experienced a flood on the Rende River 14 months ago. Since the scale was small, the damage was minimal, it did not attract much attention, and it seems to have left little impression on local residents, who do not seem to remember it very well. Furthermore, during the 7.8-magnitude Nepal earthquake in 2015, depending on the seismic intensity, the southern slope of Mount Langtang Lirung collapsed from a height of approximately 5,000 meters and slid down about 2,000 meters. The beautiful Langtang Valley—once considered a mecca for Himalayan mountaineers and enthusiasts—was completely destroyed. More than 200 people lost their lives in that disaster.
The people of Nepal are saying that this natural disaster may mark the beginning of the destruction of the Himalayas—and indeed, of the Earth itself. The Himalayas, often referred to as the “Third Pole” after the North and South Poles, are of vital importance in terms of water reserves and continental formation, so the gravity of these words resonates deeply.