The Himalayan mountains are home to many glaciers and lakes that are vulnerable to sudden flooding, which can cause serious damage to nearby communities. In August 2024, a major flood in Nepal’s Thame Valley was triggered by heavy rains and fast melting of glaciers, which broke natural dams holding back glacial lakes. This released large amounts of water and sediment, damaging homes and infrastructure downstream.

To better understand and monitor such floods, our study used satellite images and elevation data to accurately map glacial lakes and floodwaters mixed with sediment at high mountain elevations. We developed a new, simpler method that improves detection by combining water and sediment signals with height information, reducing errors caused by snow or clouds.

Our results closely matched the actual flooded areas from the 2024 event, showing the method’s reliability. This approach can help authorities track flood risks and sediment flows more effectively in remote Himalayan regions, improving early warning and disaster management as climate change increases the likelihood of such hazards.