2026 Jiangyuan Expedition Launches with First-Ever Radon Monitoring
The 2026 Jiangyuan comprehensive scientific expedition officially launched on August 2 in Yushu Tibetan Autonomous Prefecture, Qinghai Province, according to Xinhua News. Led by the Yangtze River Scientific Research Institute under the Changjiang Water Resources Commission, the week-long expedition marks the latest chapter in a decades-long effort to understand and protect the source region of China’s longest river.
A New Dimension in Monitoring
For the first time in the program’s history, researchers have added radon monitoring in water bodies to the expedition’s observation system. Radon, a naturally occurring radioactive gas that dissolves readily in groundwater, serves as a natural tracer to help determine the conversion characteristics between surface water and groundwater in the Jiangyuan region. This innovation provides more comprehensive data support for clarifying the composition of runoff components in the area, expedition leaders explained.
“Compared with previous years, this year’s comprehensive scientific expedition observation system is more complete,” the expedition leader noted, adding that the radon monitoring will help scientists better understand how groundwater contributes to river flow in this high-altitude environment.
Fieldwork Under Challenging Conditions
The Zhimenda River section, at the outlet of the Tongtian River in the Yangtze River source area, served as the expedition’s first stop. More than 20 researchers from multiple disciplines arrived at Yushu at noon on August 2 and immediately proceeded to the survey site. With the Tongtian River in flood season, team members overcame high-altitude oxygen deficiency and swift currents to collect suspended sediment, riverbed deposits, and aquatic organism samples. They used multi-parameter testers to measure water quality, dissolved oxygen, and conductivity on-site.
The expedition will continue systematic surveys of water resources and ecological conditions across the Yangtze River’s main source (Tuotuo River), southern source (Dangqu), northern source (Chumaer River), and the Lancang River source. Research areas include hydrology, sediment content, river channel conditions, soil erosion, glaciers, permafrost, and topography.
A Legacy of Scientific Exploration
The Jiangyuan region, located in the hinterland of the Qinghai-Tibet Plateau at an average altitude exceeding 4,500 meters, is a sensitive response zone to climate change and an ecologically fragile area. It forms part of the Three-River-Source area, often called the “Chinese Water Tower” for its critical role in supplying water to downstream regions.
China’s scientific exploration of the Yangtze source dates back to 1976, when New China’s first organized expedition to the region confirmed the Tuotuo River as the river’s true source and established the Yangtze’s length at 6,300 kilometers, making it the world’s third-longest river. As documented in Macau Monthly’s account of the expedition history, the 24-member team signed a “determination letter” before setting out, facing “no people, no roads, no maps” conditions to reach the Geladandong Snow Mountain.
Since 2012, the Yangtze River Scientific Research Institute has conducted annual comprehensive expeditions, making these the most frequent and extensive scientific research activities on the Yangtze source. The 2025 expedition, the 14th since 2012, covered nearly 20 observation points across the source region, as reported by the institute’s website.
Why This Matters
The Jiangyuan expeditions provide foundational data for the Three-River-Source National Park, China’s first national park, established in 2021. Previous research has documented significant climate change impacts on the region, including a temperature rise of approximately 1.7°C between 1956 and 2016—about twice the warming rate of the entire Yangtze River basin. Glacier retreat, increased precipitation, and rising sediment loads have all been observed.
According to the Science and Technology Daily, which republished the Xinhua report, the expedition’s goal is to understand the ecological baseline of the Jiangyuan region and provide a systematic “physical examination” for the source area. This year’s addition of radon monitoring represents a significant step forward in understanding the complex hydrological processes that sustain the Yangtze’s headwaters.
Looking Ahead
As the research team ventures deeper into the high-altitude hinterland of the Jiangyuan region over the coming week, their findings will contribute to Yangtze River protection efforts, Three-River-Source National Park construction, and understanding of how water resources and ecological environments evolve in this critical region. The China Economic Net noted that the expedition will help uncover the mechanisms behind the evolution of water resources and ecological conditions in the Jiangyuan area.
With climate change continuing to reshape the Qinghai-Tibet Plateau, the data gathered from this year’s expedition—including the new radon monitoring component—will be essential for developing adaptive strategies to protect one of the world’s most important water sources.