北京大气降水中氚时间序列的恢复

Reconstruction of Tritium Time Series in Precipitation of Beijing

20世纪60年代全球密集的核试验使大气中的氚含量显著增加,这为其在水循环研究中的应用,尤其在地下水定年研究中的应用提供了条件。然而,由于监测站点的布设等原因,大部分地区缺乏大气降水中氚的长期监测数据,给应用带来了困难。本文在分析现有大气降水氚时间序列恢复方法的原理和适用条件等的基础上,用多种方法(关秉钧法、趋势面分析法、三角形插值法和相关法)联合恢复了北京1953—2002年大气降水中的氚时间序列数据,并通过比较确定了最优算法和最优恢复曲线。

Human nuclear activities, especially intensive nuclear tests during the 1960s in the world, caused atmospheric tritium concentration increasing significantly, which provided convenient condition for global water cycle research, especially for tracer dating research of groundwater. However, due to the layout of monitoring sites and other reasons, most parts of the world are lack of monitoring data of tritium concentration in precipitation, which brought difficulties in determining the input function which is essential for groundwater tracer dating technique. Based on the analysis of principles and applicability of present reconstruction methods of tritium time series, the tritium time series in precipitation in Beijing during 1953--2002 was reconstructed using combined methods, including Guanbingjun method, trend surface analysis method, trigonometric interpolation method and correlation method. Furthermore, the best method and the best time series curve were elected through comparison of results of different methods.