The International Atomic Energy Agency (IAEA) organised an event on 14 November at its Atoms4Climate pavilion – on the sidelines of COP27 meeting in Egypt – to discuss scientific solutions being implemented to monitor and manage water availability in mountainous regions.

Approximately one-tenth of the earth’s landmass is covered in glaciers or other forms of permanent ice, according to the United Nations Environment Programme (UNEP). This ice is often one of the only sources of fresh water in high altitude regions, and as it melts populations increasingly face water scarcity. The event brought together partners and collaborators of the IAEA, including UNEP and the governments of Nepal and Bolivia.

The many people in Nepal who depend upon the Himalayan glaciers as a water source are now facing a water crisis, and entire villages have had to relocate. To address the increasing water scarcity, the country plans to install a cosmic ray neutron sensor with IAEA support in early 2023, to provide measurements that can inform the development of improved adaptation measures. “Improved research tools are crucial – data collection through nuclear techniques can identify subtle changes in the environment,” said Binod Heyojoo, Campus Chief at Tribhuvan University, Pokhara Campus, in Nepal.

Evidence-based data provided by the cosmic ray neutron sensor enables policymakers in mountainous regions to develop approaches that help their countries to adapt to new environmental conditions.

“Nuclear science and technology provides countries with accurate and reliable data to make climate change adaptation policies that will ensure access to resources, such as water and food, for future generations,” said Christoph Henrich, Programme Management Officer at the IAEA.

Since 2014, the IAEA has been working with mountainous countries to measure glacial retreat and the impact that this has on the availability of soil and water resources, through the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture. The Centre uses nuclear techniques, such as cosmic ray neutron sensors and isotopic tracing, which provide precision of measurements.

“The data collected by cosmic ray neutron sensors could lead to the development of early warning systems for signs of water scarcity due to climate change,” said Edson Ramirez Rodriguez, Teaching and Research Associate at the Universidad Mayor de San Andrés, Instituto de Hidráulica e Hidrología, in Bolivia. Rodriquez highlighted the advantages of cosmic ray neutron sensors, which eliminate the traditional need for extensive sampling and are able to estimate soil moisture in up to 30 hectares of land at once.

In December 2021, the IAEA installed a cosmic ray neutron sensor near El Alto, Bolivia, to measure soil moisture in wetlands at about 4500 metres above sea level – the first sensor installed at such a high altitude. Glacier meltwater is crucial to El Alto, as it is the only readily available source of freshwater for drinking, for agriculture, and even for hydropower. However, from the Andes to the Himalayas, glaciers around the world have been retreating at an accelerated rate for four decades due to global warming.

“The previously used conventional methods and techniques have already reached their limit of applicability, because they are too labour-intensive and not as precise”, added Rodriguez. He highlighted that the cosmic ray neutron sensor will be part of a more ambitious project in Bolivia – the development of an early warning system, supported by a Bolivian communication satellite, that will help detect and characterise the arrival of extreme events of droughts and floods through the identification of critical thresholds related to the moisture content in the soil.

“We are able to access real-time soil moisture measurements of our monitoring site online,” Rodriguez said. The warning system is ­expected to be completed in 2023.

In June this year, scientists from both the Andes and Himalayas learned about the effects of climate change on soil and water resources in their regions at an interregional IAEA training course in Bolzano, Italy, in collaboration with the United Nations University.

“Climate change crosses borders and disciplines, and collaborative spaces, such as the Mountain Partnership, allow us to tackle this challenge by involving multiple and key stakeholders from different fields, especially by bringing countries closer to experts, scientists and new technologies, enabling them to make better climate policy decisions based on scientific evidence," said Dianna Kopansky, UNEP Coordinator of the Global Peatlands Initiative.

“This event underscores the importance of working with partners and stakeholders to help communities use nuclear technology to collect data that will support their efforts to adapt to climate change, and ultimately build resilience,” Henrich said.


Image: Installation of a Cosmic Ray Neutron Sensor in Bolivia (courtesy of Edson Ramirez)