Abstract: This article delves into the impact of severe drought during the flood season in 2022 on sediment erosion and deposition in the Three Gorges Reservoir (TGR). Employing the sediment-transport balance method, we assessed the changes in total sediment deposition in TGR and utilized topographic change methods to analyze sediment distribution in the reservoir. These analyses reveal significant alterations in sediment deposition patterns compared to previous years due to inflow plunges in the flood season of 2022. The annual sediment deposition volume in the Three Gorges Reservoir, calculated at 10.97 million tons using the sediment balance method, has approached historically low levels since the impoundment. However, morphological cross-sectional calculation results indicate 15.7 million m³ of erosion in the reservoir’s riverbed, encompassing fluctuating and perennial backwater areas. The primary cause of this “pseudo-scouring” phenomenon is inadequate sediment input to offset riverbed settling. To address scientific scheduling needs for the Three Gorges Project, we recommend enhancing research on sediment compaction laws and influencing mechanisms in the reservoir area. Additionally, attention should be directed towards understanding the evolution of riverbed scouring and siltation under specific hydrological conditions.

Key words: sediment deposition, drought during flood season, sediment transportation, streamflow, Three Gorges Reservoir