摘要
以鄱阳湖洪泛区湿地为研究区,运用FEFLOW建立地下水流数值模型,定量评估2022年极端干旱影响下地下水文条件的时空响应特征.结果表明,2022年极端干旱对鄱阳湖的持续影响主要发生在下半年7~12月份,极端干旱会导致鄱阳湖洪泛区地下水位大幅度下降以及地下水流速整体加快,且两者变化情况均呈现出明显的空间异质特征.总体上,极端干旱影响的地下水位最大降幅可达5m左右,地下水流速增加幅度约为正常年份的1~2倍,极端干旱的强烈影响区域主要分布在洪泛区的东北部.从原因上分析,降水对地下水的补给量明显减少以及地下水向湖泊的排泄量显著增加,这些均是极端干旱条件下洪泛区地下水储量减少的主要原因.从年尺度上来说,极端干旱导致洪泛区系统的地下水排泄量增加了1.62×10^(7)m^(3),约是基准年地下水排泄量的14.5倍.鄱阳湖及其洪泛湿地作为整个流域地下水的重要排泄区和生态屏障区,本研究强调了湖泊和地下水文情势响应变化的重要性.
The recognition and attention of groundwater in the river-lake system was done gradually strengthened.The current research used the floodplain area of Poyang Lake as our study area.We further used the FEFLOW groundwater flow model to quantitatively evaluate the spatiotemporal responses of floodplain groundwater under the extreme drought condition in 2022.The simulation results showed that the continuous impact of extreme drought on Poyang Lake in 2022 mainly occurs in the second half of the year.The extreme droughtleaded to a significant decrease of floodplain groundwater level and an overall acceleration of groundwater flow velocity in the lake’s floodplain.The decreasing trends of both the groundwater level and flow velocity exhibited an obvious spatial heterogeneity.In general,the maximum drop of groundwater levels affected by the extreme drought reaches about 5m,and the groundwater flow velocity was about once-twice than that of the normal year.In addition,extreme drought might result in a significant decline in rainfall recharge and a significant increase in groundwater discharge(into the lake),contributed to the decline of floodplain groundwater storage.On an annual scale,the extreme drought might lead to increasing groundwater discharge of 16.2×10^(6)m^(3) in the study area,which was about 14.5 times than that of groundwater discharge in the normal year.Poyang Lake and its floodplain are important drainage and ecological barrier areas of the whole basin groundwater flow system,and therefore,this study highlights the importance of lake and groundwater hydrological responses.
作者
曹思佳
李云良
陈静
姚静
赵贵章
李志萍
CAO Si-jia;LI Yun-liang;CHEN Jing;YAO Jing;ZHAO Gui-zhang;LI Zhi-ping(Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210009,China;Monitoring Center of Jiangxi Hydrology,Nanchang 330002,China;School of Earth Science and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450045,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第12期6601-6610,共10页
China Environmental Science
基金
国家重点研发计划项目(2019YFC0409002)
国家自然科学基金项目(42071036)
中国科学院青年创新促进会项目(Y9CJH01001)联合资助.
关键词
鄱阳湖洪泛湿地
地下水
极端干旱事件
水文水动力
地下水储量
数值模拟
Poyang Lake floodplain
groundwater flow simulation
extreme drought event
hydrological and hydrodynamic
groundwater storage volume
numerical simulation
