摘要
岩溶地下水的δ13 CDIC值主要是受土壤碳库和碳酸盐岩碳库的δ13 C所制约。本研究选取两个气候条件完全不同的南方广西桂林、北方山西汾阳为对比研究对象,通过取样测试分析两个地区岩溶地下水的δ13 CDIC值,发现北方汾阳岩溶地下水的δ13 CDIC范围为-7.53‰～-12.25‰,平均为-9.84‰;南方桂林岩溶泉水的δ13 CDIC范围为-9.22‰～-15.99‰,平均为-13.06‰;北方岩溶水比南方偏重3.22‰。结合两个地区所处的气候环境条件分析,北方暖温带干旱半干旱大陆性季风区,C4植被发育,C3/C4比例低,土壤碳库的δ13 C重;南方亚热带湿润季风区C3植被发育,C3/C4比例高,土壤碳库的δ13 C轻。因此气候条件不同引起生态条件的差异而造成南北方地下水δ13 CDIC的不同。这为利用同位素方法研究地下水对气候条件变化的响应提供了理论依据。
The δ^13 CDIC values of karst groundwater are mainly constrained by the soil carbon pool and its δ^13C . We selected two regions which are completely different in climatic conditions, Guilin of Guangxi in southern China and Fenyang of Shanxi Prov- ince in northern China, as the contrast objects for our study. Through analyzing the δ^13CDIC values of kart groundwater in the two regions, it was found that： （a） the δ^13CDIC values of karst groundwater are within the range of -7.53‰-12.25‰,with a mean value of --9.84‰ in Fenyang, and those of karst spring are within the range of -9.22‰--15.99‰, with a mean value of --13.06‰ in Guilin; （b） the karst groundwater in northern China is 3.22‰ times heavier than that in southern China. Combining the climatic and environmental conditions in the two regions, we revealed that the northern warm temperate arid and semi-arid continental monsoonal elimate is characterized by more development of C4 vegetation, lower C3/C4 ratios and heavier δ^13C of soil organic carbon pool. On the contrary, the southern subtropical humid monsoon region is characterized by less de- velopment of C4 vegetation, higher C3/C4 ratios and light δ^13C of soil organic carbon pool. Therefore, different ecological con- ditions caused by the climate are the reason which caused different δ^13CDIC values of water between southern China and northern China. The study provides a theoretical basis for our study on the response of groundwater to climate changing with isotope methods.
出处
《地球与环境》
CAS
CSCD
北大核心
2012年第4期505-511,共7页
Earth and Environment
基金
中国地质调查项目(1212011087121)
