| 摘要: |
| 【目的】揭示鄱阳湖水文干旱演变过程及其归因。【方法】基于1953—2022年逐日水位数据，采用日可变阈值方法识别水文干旱事件及其变化特征，通过梯度提升算法（XGBoost）分析长江及鄱阳湖5个河流水量与鄱阳湖水文干旱之间的关系，评估不同河流来水对湖泊水文干旱的贡献。【结果】鄱阳湖年际水位波动明显，平均水位呈下降趋势，湖泊水位的空间梯度差异逐渐缩小；湖口和都昌站分别经历了71次和68次水文干旱事件，其中2022年的水文干旱最为严重；自2003年，都昌和湖口站平均干旱历时分别延长了18.4 d和20 d，干旱强度分别增加了2.16倍和3.09倍；长江对鄱阳湖水文干旱的影响从湖口向湖中减弱，自2003年，五河来水对湖区水文干旱的影响显著增强。【结论】优化三峡大坝和鄱阳湖流域控制性水利工程的调度，提高流域水源涵养服务，防范极端水文干旱事件至关重要。 |
| 关键词: 鄱阳湖；水文干旱；XGBoost；干旱演变过程；水位变化 |
| DOI：10.13522/j.cnki.ggps.2024433 |
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| 基金项目: |
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| Temporal dynamics of hydrological drought and its drivers in the Poyang Lake |
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WANG Nong, HAN Huiming
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1. Jiangxi Academy of Water Sciences and Engineering, Nanchang 330029, China;
2. School of Infrastructure Engineering, Nanchang University, Nanchang 330031, China
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| Abstract: |
| 【Objective】Poyang Lake is the largest freshwater lake in China, playing a vital role in regional water supply and ecosystem functions. In recent decades, however, it has experienced increasingly frequent and severe hydrological droughts. In this paper, we analyze the temporal variation of droughts in the lake and identify the contribution of the inflows of its five major tributaries and the Yangtze River.【Method】Based on daily hydrological data measured from 1953 to 2022, we identified hydrological drought events and their characteristics using the daily-variable threshold method. The XGBoost model was then used to investigate the relationship between the drought events and the inflows of the five tributaries: Ganjiang, Fuhe, Xinjiang, Raohe and Xiuhe, as well as the Yangtze River, and to assess the contribution of each river.【Result】The results showed a long-term decline in the average water level of Poyang Lake from 1953 to 2022, accompanied by diminishing spatial gradients across the lake. After 2003, the average drought duration increased by 18.4 days at Duchang Station and 20 days at Hukou Station, with their drought intensity increasing by a factor of 2.16 and 3.09, respectively. Spatially, the influence of the Yangtze River on the hydrological drought decreased from the mouth toward the interior regions, while the inflows from the five tributaries have become the primary drivers of drought events, particularly after 2003.【Conclusion】From a basin-wide perspective, optimizing the operation of the Three Gorges Dam, improving the regulation of water conservancy projects in the basin, and strengthening water conservation measures are critical for mitigating extreme hydrological droughts and maintaining ecosystem stability in the basin. |
| Key words: Poyang Lake; hydrological drought; XGBoost; drought evolution process; water level change |
