| 摘要: |
| 洪泛湖泊水文干旱及其对水文连通性的影响对当地水资源管理和湿地生态保护至关重要。基于ESTARFM（Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model）模型重构的鄱阳湖区2000—2023年高时空分辨率淹水数据集，采用标准化淹水面积指数定量表征鄱阳湖洪泛系统水文干旱，并结合地统计水文连通性函数，研究分析了鄱阳湖区水文干旱和水文连通性演变特征；在此基础上，采用STL（Seasonal and Trend decomposition using Loess）时间序列分解及多元线性函数拟合法，明确了水文连通性对水文干旱变化的响应规律。研究表明，鄱阳湖区水文干旱的年内和年际变化较为复杂，干旱事件的发生频率较高，且整体上呈现旱情增加趋势。鄱阳湖区南北水文连通性强于东西水文连通性，近年来湖区水文连通性呈现出波动下降趋势，与湖区水文干旱强度变化有关。定量分析发现，随着水文干旱程度的增强，鄱阳湖区水文连通性呈现下降趋势。其中，东西方向上，鄱阳湖区轻旱、中旱、重旱、极旱较无旱情境下年均水文连通性分别降低45.2%、50.0%、54.6%和70.7%；南北方向上，年均水文连通性分别降低32.1%、35.6%、39.0%和50.7%。鄱阳湖区水文干旱引起的水文连通性变化将对湿地植被的生长分布产生重要影响，研究结果为极端水情下的湖泊生态系统管理实践提供依据。 |
| 关键词: 洪泛系统 水文干旱 水文连通性 数据融合 鄱阳湖 |
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| 基金项目:国家自然科学基金(42071028)，国家重点研发计划(2022YFC3204102)，重庆市雏鹰计划项目(CY240227) |
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| Impact of hydrological drought on hydrological connectivity in the Poyang Lake floodplain system* |
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yueenxin,zhaolin,qianpinyu,liuyi,lixianghu,zhaohuaqiong,yexuchun
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Southwest University
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| Abstract: |
| Scientific research on hydrological drought in lake-floodplains and its impact on hydrological connectivity is of great significance for local water resources management and wetland ecological protection. Based on the reconstructed high spatiotemporal resolution inundation datasets from 2000 to 2023 by applying the ESTARFM model (Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model), hydrological drought and hydrological connectivity in the Poyang Lake were quantitatively characterized by the standardized inundation area index and the geostatistical hydrological connectivity function, and then their evolution characteristics were analyzed. On this basis, the response of hydrological connectivity to hydrological drought was further clarified by using the methods of STL (Seasonal and Trend decomposition using Loess) time series decomposition and multivariate linear fitting function. The results showed that both annual and interannual variations of hydrological drought in Poyang Lake were complicated, with a high frequency of occurrence and an increasing drought tendency. The hydrological connectivity in the north-south direction of the Poyang Lake is stronger than that in the east-west direction. In recent years, the hydrological connectivity of the Poyang Lake has shown a fluctuating downward trend, which is related to the intensity changes of lake hydrological drought. Further quantitative analysis found that with the increase of the degree of hydrological drought, hydrological connectivity in the Poyang Lake showed a decreasing trend. In the east-west direction, the annual average hydrological connectivity of light drought, medium drought, severe drought and extreme drought in the Poyang Lake can decrease by 45.2%, 50.0%, 54.6% and 70.7%, respectively, compared to no drought scenario. Similarly, in the north-south direction, the annual average hydrological connectivity can decrease by 32.1%, 35.6%, 39.0% and 50.7%, respectively. The changes of hydrological connectivity caused by hydrological drought in the Poyang Lake area will further impact affect the growth and distribution of wetland vegetation, and the results of this study provide scientific basis for the management practice of lake ecosystems under extreme water conditions. |
| Key words: lake-floodplain system hydrological drought hydrological connectivity data fusion Poyang Lake |
