October 9, 2025
THIMPHU – With support from the International Centre for Integrated Mountain Development (ICIMOD), the National Centre for Hydrology and Meteorology (NCHM) will soon establish an autonomous black carbon monitoring station at high altitudes.
The initiative aims to determine whether black carbon is present in glaciers and higher altitudes, where its deposition accelerates the melting of ice and snow.
Black carbon is a fine particulate pollutant produced by burning fuels like coal, diesel, wood, or crop waste. When it settles on glacier surfaces, it darkens the ice, absorbs more heat, and accelerates melting.
While studies on the Tibetan Plateau and other Himalayan regions have confirmed that black carbon enhances melting rates, no such research has been conducted in Bhutan.
According to the NCHM, Bhutan has 567 glacial lakes within its four river basins, 17 of which are classified as potentially dangerous. Thorthormi Lake is considered the most critical.
Director of NCHM, Karma Dupchu, said that Bhutan has limited data on black carbon.
“Currently, there are no black carbon monitoring stations in Bhutan,” he said. “Under a partnership with ICIMOD, we will receive technical assistance and instruments to establish stations, starting with the Shodug Glacier headwaters.”
ICIMOD’s Air team will lead the equipment installation, addressing a major data gap in understanding black carbon’s impact on Bhutan’s glaciers.
This partnership between NCHM, the Department of Local Governance and Disaster Management (DLGDM), and ICIMOD is designed to strengthen Bhutan’s cryosphere monitoring, research, and disaster preparedness.
An official said that the collaboration will enhance catchment-scale cryosphere monitoring and research in the Shodug Glacier Catchment, improving the accuracy and timeliness of cryosphere and weather data sharing.
He added that the partnership will also build Bhutan’s capacity to monitor permafrost in unexplored areas.
As a first step, in November 2024, NCHM and ICIMOD initiated pilot permafrost monitoring by installing 19 HOBO Tidbit temperature sensors in the headwaters of the Wangchu River at Yaree La.
The Shodug Glacier was selected for long-term mass balance monitoring and catchment-scale integrated studies due to its proximity to Thimphu.
Institutional and community support
Field staff often face logistical challenges when monitoring for glacial lake outburst floods (GLOFs), as they must camp at remote sites.
NCHM reported that during past events in 2019 and 2023, essential equipment could not be transported due to helicopter weight limits.
To address this, ICIMOD and NCHM plan to pre-position camping gear at the Lunana field office, with support continuing until 2029. Longer-term plans include providing high-end equipment.
Currently, NCHM operates 17 manual snow stations across Bhutan, but limited resources have made it difficult to develop seasonal and daily snow cover maps.
“ICIMOD will provide technical support for satellite-based snow cover mapping to enhance Bhutan’s monitoring capabilities,” an official said.
Beyond glacier and snow monitoring, the partnership will pilot a Community-Based Flood Early Warning System in the Haa watershed. This system will provide end-to-end flood warnings, enabling vulnerable communities to take anticipatory action.
The project will also test community awareness systems in highly vulnerable areas like Apachu.
“In response to the rising number of disasters, especially flash floods, we aim to pilot community awareness systems in vulnerable catchments,” said the NCHM Director Karma Dupchu. “Communities in Trashiyangtse, Trashigang, and other districts have expressed the need for an early warning system.”
Capacity building and knowledge exchange
The project also includes extensive capacity building.
ICIMOD and its partners will provide need-based experts in areas such as machine learning, climate modeling, workflow automation, cryosphere, hydrology, meteorology, climate, air studies, and disaster risk reduction.
“Besides monitoring, a great deal of capacity building, knowledge sharing, and skills exchange will occur under this project over the next two years,” an official said.
ICIMOD has committed approximately USD 164,000 in-kind for goods and services. All contributions will be managed directly by ICIMOD, with no funds transferred to NCHM or DLGDM.
Officials said the goal is to enhance Bhutan’s knowledge of glaciers, permafrost, and related cryosphere systems while addressing urgent disaster risks.
“Primarily, this initiative aims to deepen our understanding of glaciers and permafrost,” the Director Karma Dupchu said. “Concurrently, due to the rising number of disasters, we are piloting community-based awareness and early warning systems, where communities take charge of maintenance with NCHM’s technical support.”