| 长沙地区不同水体稳定同位素特征及其水循环指示意义 |
| 摘要点击 2983 全文点击 1228 投稿时间：2014-11-28 修订日期：2015-01-19 |
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| 中文关键词 稳定同位素 不同水体 水循环 大气水线 长沙地区 |
| 英文关键词 stable isotope different water bodies water cycle meteoric water line Changsha |
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| 中文摘要 |
| 分析不同水体中的环境同位素变化特征是应用同位素示踪技术进行区域水循环研究的必要基础. 根据2012年1月至2013年12月对长沙地区大气降水、地表水(河水)及地下水(泉水、井水)的跟踪取样,分析了不同水体中δD、δ18O的变化特征. 结果表明,由于水汽来源的季节差异,长沙地区降水中D、18O的组成呈现出明显的季节变化,降水中δ18O变化与气温、降水量等气象要素之间存在显著负相关,当地大气水线(LMWL)特征揭示了长沙地区湿润多雨的气候; 地表水中δD、δ18O的波动小于降水,其稳定同位素值的季节变化相对于降水存在延迟特征,冬夏半年河水线(RWL)的差异表明地表水在不同季节的主要补给源有所不同; 地下水中δD、δ18O的波动幅度最小,并且泉水、井水中δD与δ18O的变化范围以及平均值都非常接近,说明这两种水体间存在较密切的水力联系,干旱月份地下水δD、δ18O持续偏低,可能与树根对地下水的吸取加强有一定的关系. 研究结果对于合理利用本地区水资源有一定指导意义. |
| 英文摘要 |
| Analysis of the variation characteristics of different water bodies is the basis of applying isotopic tracer technique in regional water cycle research. Based on the samples of atmospheric precipitation, surface water (river water) and groundwater (spring water and well water) in Changsha from January 2012 to December 2013, the study analyzed the variation characteristics of δD and δ18O in different water bodies. The results showed that the values of D and 18O in precipitation of Changsha showed obvious seasonal variation because of the seasonal difference of the water vapor source, and it showed significant negative correlation between δ18O in precipitation and some meteorological factors such as the temperature and the amount, the local meteoric water line revealed the climatic characteristic of humid and rainy in Changsha; the fluctuation of δD and δ18O in surface water was more moderate than those in precipitation, and the seasonal variation of stable isotope value showed lagging characteristic compared with that in precipitation, the difference of river water line (RWL) indicated that the main supply sources of surface water were changing in different seasons; the fluctuation of δD and δ18O in groundwater was the least, the variation ranges and mean values of δD and δ18O in spring water and well water were very close, it showed that there were some hydraulic connections in the two water bodies, the values of δD and δ18O in groundwater were constantly lower during drought months, this phenomenon might have a certain relationship with the increasing absorbency of tree roots from groundwater. The results of the study have certain guiding significance for rational utilization of water resources in the region. |
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