摘要
为研究鄂西南岩溶山区的水循环过程,以湖北宜昌香溪河流域为研究对象,通过现场调查并结合环境同位素,对香溪河流域地表水和地下水进行了取样,通过测定其氢氧同位素组成,分析了同位素变化特征以及流域地下水和地表水的转换关系及其水循环特征。流域水中δD、δ18 O值组成分析表明:流域内各种水体主要分布在当地大气降水线的附近,构成斜率明显小于雨水线的蒸发线,3个子流域δD、δ18 O值的富集程度为:南阳河流域<古夫河流域<高岚河流域。南阳河流域上游受神农架山区地方性大气降水控制。响水洞和响龙洞(暗河出口)水中氘过量参数(d)值分别反映出不同的地下径流途径与滞留时间、水岩反应强度。子流域同位素沿程变化的特征反映出:在上游段,水来源不同以及地表水和地下水转换频繁是δD、δ18 O值变化的主要影响因素;在中下游段,流域内地下水流入河流,河水流量逐渐增大,不同的水源混合均匀,经过一定的蒸发作用,δD、δ18 O值的变幅趋于稳定。
To study the hydrologic cycle process of karst mountainous area in southwest of Hubei Province, field survey was performed and the environmental isotopes in the stream and ground water was analyzed. Specifically, we first divided the Xiangxi River basin in Yichan Hubei into three sub-basins, which are Nanyang, Guru and Gaolan river basins. We sampled stream and ground water from each sub-basin, deter-mined the isotopic composition of hydrogen and oxygen elements in the water and analyzed the reciprocal transformation of stream and ground water as well as water cycle characteristics based on the isotopic com- position of the elements. The composition analysis of δD,δ^18O indicated that： （1） Water from Gaolan drainage basin showed the highest enrichment of δD and δ^18O , while water from Nanyang basin showed the lowest, suggesting that Nanyang basin is controlled by the rainfall from its upstream Shennongjia moun- tain area. （2） The value of δD and δ^18O varied from one sub-drainage basin to another suggests that the surface and ground water mainly spread along the local meteoric water line. （3） The d value of water from Xiangshui Cave and Xianglong Cave （outfalls of underground streams） reflects the different underground water paths, residence time and water-rock interaction intensity. The characteristic that sub-basin isotope value is changed by flow showed that at the upstream, the variation of δD and δ^18O value is caused by and reflects the source of water and the reciprocal transformation of surface and ground water. At the down- stream, the variation of δD and δ^18O value becomes stable, which is due to the increase amount of water current, mix and evaporation of water of different origins.
出处
《地质科技情报》
CAS
CSCD
北大核心
2012年第6期161-167,共7页
Geological Science and Technology Information
基金
中国地质大学(武汉)教育部长江三峡库区地质灾害研究中心项目"创新学科平台建设"和"地质环境演变及保护研究"
中央高校基本科研业务费专项资金资助项目(CUG120819)
关键词
环境同位素
岩溶山区
水循环
香溪河流域
environmental isotope
karst mountains
hydrological cycle
Xiangxi River basin
