黄河河龙区间输沙量时空突变特征及驱动因素分析OA

The He-Long Region(Hekouzhen to Longmen)of the middle reaches of the Yellow River is a major source of sediment for the en-tire river.Understanding the spatiotemporal abrupt changes in sediment transport and the underlying driving factors is crucial for optimizing water resource utilization and developing a scientific water-sediment regulation system for the middle reaches of the Yellow River.Based on sediment transport data from 22 sub-basins in the He-Long Region between 1955 and 2016,this study analyzed change trends and time of ab-rupt changes in sediment transport during the study period,and further explored the contribution rates of climate change and human activities to sediment reduction.The results showed that:21 sub-basins in the study showed a significant decreasing trend in annual sediment trans-port,with abrupt changes occurring primarily in the 1980s and 1990s.The spatial distribution characteristics of annual sediment load in the He-Long reach were fundamentally consistent between the baseline period(P1)before the change point and the human-activity-impacted pe-riod(P2)after it,with a significant reduction occurring in P2.The primary sediment-producing areas were concentrated in the Wuding River and Kuye River Basins.The average contribution rates of precipitation and human activities to sediment reduction of 22 tributaries were 24.42%and 75.58%,respectively,with large-scale soil and water conservation project constructions being the primary driver of sediment reduction.