About the Response

On August 26, 2026, devastating floods and mudslides swept through the Lhende Khola river valley, leading to a heavy toll on lives and damage to critical infrastructure. As of August 31, 2026, at least 903 people had lost their lives and 4,247 people were reported missing in Nepal, with an additional 16 lives lost and 546 missing in the Tibet Autonomous Region of China. In particular, the Rasuwa District was heavily affected by the disaster.

In response, HOT's Open Mapping Hub - Asia-Pacific and NAXA, in collaboration with the local mapping community MapBuds, launched a coordinated humanitarian mapping initiative focusing on the Bhote Koshi and Trishuli river valleys.

In addition, HOT worked with imagery providers, including local drone operators and Vantor, to coordinate and share critical, open imagery needed to assess the affected areas pre- and post-disaster.

The initiative is being coordinated closely with the Nepal National Disaster Risk Reduction and Management Authority (NDRRMA) to identify priority mapping needs and provide essential open geospatial data to support emergency response, recovery, and longer-term reconstruction efforts.

How You Can Support

• Map via HOT Tasking Manager

We are seeking intermediate-level volunteer mappers to support mapping activities through the HOT Tasking Manager. Current tasks focus on mapping buildings, roads, and residential settlement areas across priority upstream and downstream areas of the Bhote Koshi and Trishuli river valleys.

• Share your data needs

If you are part of an organization or community involved in the response and have OSM data needs, please reach out to bernard.heng@hotosm.org to share your priority locations and/or features for mapping.

Access the Data

Data is available for download through the Humanitarian Data Exchange (HDX), with continuous updates as mapping progresses and new information becomes available:

• Flood Affected Area – Targeted data on areas affected by the floods
• River Corridor – Data covering the entire Bhote Koshi and Trishuli river corridors
• fAIr Damage Assessment – AI-scored building damage from post-event imagery

Latest Progress

Progress as of September 3, 2026:

• Five HOT Tasking Manager projects have been launched to map buildings, roads, and residential settlements in priority upstream and downstream areas.
  • Buildings and roads data in the affected areas have been 100% mapped and validated.
  • Residential settlement boundaries have been 100% mapped and are currently undergoing validation.
• More than 300 global contributors have participated in the mapping efforts. Together, they mapped 19,000+ buildings and 400+ km of roads in the affected areas (Source: ohsomeNow).
• 2600+ dataset downloads from HDX.

The activation team will continue coordinating with NDRRMA, local stakeholders, humanitarian partners, and the mapping community to identify emerging data needs and priorities for further mapping activities.

Thank you to everyone who has contributed their time and expertise to the mapping efforts so far.

For latest updates and complete information about the activation, visit the activation’s wiki page.