From June 22 to July 1, 2025, supported by the Formation Mechanism and Dredging Methods of Sandbars at Confluence Areas of the Yellow River Mainstream and Tributaries, a Key Project of the Yellow River Program, National Natural Science Foundation of China, NHRI research team conducted the field tests of unmanned pneumatic sand-flushing and silt reduction during the water-sediment regulation period at the Xiaolangdi Reservoir on the Yellow River. During the tests, unmanned surface vessels equipped with pneumatic sand-flushing devices operated precisely at the entrance of the Zhenshui tributary. By using high-pressure gas to disturb and suspend deposited silt to the water surface, the silt was efficiently transported out of the reservoir with the outflow hydrodynamic force generated during the reservoir water-sediment regulation operations.

Near 50% storage capacity of the Xiaolangdi Reservoir is distributed in its tributary areas, while the widespread presence of sandbars at tributary entrances severely restricts the utilization of these areas. Though water-sediment regulation has proven highly effective for siltation management in the main channel of the reservoir, its impact on tributary siltation, particularly sandbars, has been minimal. To address this, the pneumatic sand-flushing technology is deployed during water-sediment regulation to reduce siltation and increase storage capacity. Originally proposed by NHRI in the 1980s, the technology has undergone years of independent R&D and equipment optimization by the research team. The first successful integration of unmanned surface vessel autonomous navigation with pneumatic sand-flushing has laid technical foundation for large-scale, integrated applications in the future. The successful tests also mark substantial progress in the unmanned and intelligent development of this technology.

The pneumatic sand-flushing technology has previously been applied in localized complex siltation scenarios of the Zhoushan Port in Ningbo, tidal sluice gates in coastal areas in northern Jiangsu, and the Qinhuai River estuary. The achievements of this unmanned sand-flushing tests at the Xiaolangdi Reservoir provide a new practical approach for addressing siltation challenges in diverse scenarios, demonstrating significant value.