| 摘要: |
| 水是人类生存之源，而湖荡被称为地球之“肾”，是河湖水系连接的关键缓冲节点，与人类生存和发展息息相关。长三角平原水系众多，河流纵横，天然湖泊与人工沟渠遍布，平原湖荡湖水与周边地下水的水力联系较为频繁，而地下水对湖泊水均衡贡献尚不明确，对平原湖荡地下水赋存和运移规律的认识不足。本研究以苏州吴江区元荡湖为研究对象，选取氡同位素作为湖水和地下水水力交换过程的示踪剂，建立氡箱模型，揭示元荡湖不同区段与地下水的水力联系过程和补给关系，并通过水位动态验证分析湖水-地下水交互关系。枯水期元荡湖水位和氡浓度空间分布特征指示研究区内地下水向湖水排泄，其中尤以湖泊西侧较为明显，地下水入流补给的氡为7.137×106Bq/d，输入量源项占比为90%，地下水流入量为4540.80m3/d，地下水每日流入量对元荡湖水量的贡献率为2.55％。参数敏感性分析结果表明，风速与地下水222Rn活度为特别敏感参数，取值差异较大时会导致计算误差急剧增大，改善测点布置和提高模型参数精度能有效提高模型计算结果的准确性和可靠程度。借助氡同位素示踪方法，建立湖泊氡箱模型，是研究平原湖荡内地下水补、径、排特征的有效方法。本研究一定程度上提供了平原湖荡区域水量均衡的更多认识，有助于了解平原湖荡水均衡和水循环机制，为平原湖荡水资源开发利用与环境保护提供数据支撑。 |
| 关键词: 氡同位素 湖泊氡箱模型 地下水 湖水 水力交换 元荡湖 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金（51979078）、江苏省地质勘查基金项目“长三角生态绿色一体化发展示范区（江苏）生态地质调查” |
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| Study on lake-groundwater recharge fluxes during dry season in plain lakeland based on radon isotopes |
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lu xiao hui,wu chao feng,gong xu long,wu xin,wang mengyao,hu yushu,zhang haitao,wei yantong
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| Abstract: |
| Water is the source of human survival, and lake swing, known as the "kidney" of the earth, is a key buffer node connecting rivers and lakes, and is closely related to human survival and development. The Yangtze River Delta Plain has numerous river systems, natural lakes and artificial channels, and frequent hydraulic connections between the lake water and the surrounding groundwater. However, the contribution of groundwater to the lake water balance is still unclear, and the law of the occurrence and migration of groundwater in the plain lake is not well understood. In this study, Yuandang Lake, Wujiang District, Suzhou was selected as the research object, radon isotope was selected as the tracer of the hydraulic exchange process between lake water and groundwater, and a radon tank model was established to reveal the hydraulic connection process and recharge relationship between different sections of Yuandang Lake and groundwater, and the interaction relationship between lake water and groundwater was analyzed through dynamic verification of water level. The spatial distribution characteristics of the water level and radon concentration in Yuandang Lake during dry season indicate that the groundwater in the study area drains into the lake, especially in the west side of the lake. The radon recharge of groundwater is 7.137×106Bq/d, the input source term accounts for 90%, and the inflow of groundwater is 4540.80m3/d. The contribution rate of groundwater inflow to the water volume of Yuandang Lake is 2.55%. The results of parameter sensitivity analysis show that wind speed and groundwater 222Rn activity are particularly sensitive parameters, and the calculation error will increase sharply when the value difference is large. Improving the arrangement of measuring points and improving the accuracy of model parameters can effectively improve the accuracy and reliability of model calculation results. By means of radon isotope tracer method, the radon tank model of lake is an effective method to study the characteristics of water feed, diameter and discharge in the lake plateau. To a certain extent, this study provides more understanding of the water balance in the plain lake swing region, helps to understand the water balance and water circulation mechanism in the plain lake swing region, and provides data support for the development and utilization of water resources and environmental protection in the plain lake swing region. |
| Key words: radon isotopes lake radon box model groundwater lake water hydraulic exchange YuanDang Lake. |
