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| DOI：10.13522/j.cnki.ggps.2025057 |
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| Analysis of runoff and sediment variability and its causes in the upper reach of the Dang River |
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YANG Nini, NIU Zuirong, ZHANG Pengju, JIA Ling
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1. College of Water Conservancy and Hydropower Engineering, Gansu Agricultural University, Lanzhou 730070, China;
2. Water Resources Utilization Center of Shule River Basin, Gansu Province, Yumen 735211, China
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| Abstract: |
| 【Objective】Understanding the variation in hydrological and sedimentary processes and the underlying mechanisms is essential for integrated watershed management, particularly in arid inland basins. As a major tributary of the Shule River, the Dang River plays a key role in water resource regulation in the Hexi Corridor. This study analyzes the long-term changes in runoff and sediment load in the upper reach of the Dang River and its underlying mechanisms. 【Method】The analysis was based on precipitation, runoff, temperature and sediment transport measured from 1972 to 2022. The variations in hydrological and sediment transport were examined using the Mann-Kendall trend test, the cumulative anomaly analysis, and the double mass curve method. A quantitative attribution analysis was used to assess the influence of climate change and anthropogenic activities.【Result】 ① Runoff and sediment transport showed strong seasonal variation, with their peaks occurring in July and August, primarily during spring and summer. ② Over the 50-year period, runoff displayed a significant increasing trend (Hurst index＞0.5), while sediment load exhibited a decreasing but statistically insignificant trend. Abrupt changes were identified in 1986 for runoff and 2007 for sediment. Runoff exhibited dominant cycles of 12, 5, 8, and 22 years, whereas sediment dynamics were governed by cycles of 30, 14, 8, and 5 years. ③ Attribution analysis revealed that precipitation had a stronger influence on hydrological changes during Transition Period I than during Transition Period II. In Period II, precipitation contributed 196.34% to runoff variation and 65.96% to sediment change, while human activities accounted for 96.34% and 34.04%, respectively, to these variations, mainly through water regulation measures.【Conclusion】 Rising temperatures have significantly contributed to increased runoff, while precipitation remains the dominant climatic driver of sediment variation. Human interventions, such as water regulation, have had a beneficial impact on improving water–sediment relationship in the basin. |
| Key words: upper reaches of the Danghe River, runoff sediment relationship, interannual variation, precipitation, attribution analysis |
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