Characteristic of radon in typical karst water systems and its indicating significance in Guangxi, China
GUO Fang, WEI Li-qiong, JIANG Guang-hui
Key Laboratory of Karst Dynamics, Ministry of Natural Resources/Guangxi Zhuang Autonomous Region, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China
Abstract：The radioactive isotope radon originates from decay of uranium in the stratum. 222Rn has a half-life of 3.82 days, and the activity of 222Rn has significant difference in groundwater and surface water. The application of 222Rn in understanding hydrological process grows quickly in recent years, while it has less study in karst environment. Three karst water systems in Guangxi were taken as examples to study the characteristic of 222Rn in karst environment and its indicating meaning. It was found that the activity of 222Rn was less than 500Bq/m3in the upper aeration zone, while it had local anomaly high in unsaturated zone, which is related to local geological structure. In saturation zone, the residence time of groundwater, the mixing proportion of different groundwater components, and the length of the radon transport along the flow paths causes the different of 222Rn activity. In general, 222Rn in karst conduit media is higher than that in fissure media, and 222Rn in thick soil covering layer is higher than that in thin soil covering. In the discharge zone of big karst water systems, groundwater usually flows to river, and sometimes river can flow back into the spring outlet. Because the significant difference between 222Rn in groundwater and surface water, 222Rn might be an ideal tracer of quantifying groundwater-surface water interaction.
郭芳, 韦丽琼, 姜光辉. 广西典型岩溶水系统环境中222Rn的分布及指示意义[J]. 中国环境科学, 2021, 41(9): 4294-4299.
GUO Fang, WEI Li-qiong, JIANG Guang-hui. Characteristic of radon in typical karst water systems and its indicating significance in Guangxi, China. CHINA ENVIRONMENTAL SCIENCECE, 2021, 41(9): 4294-4299.
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