Liu Wen, Pu Jun-Bing, Yu Shi, Zhang Cheng, Au Yik-Yu, Yuan Dao-Xian, Yang Hui, Tang Wei
Huan Jing Ke Xue. 2014 Aug;35(8):2959-66.
To gain more knowledge on the transformation process of dissolved inorganic carbon in a karst reservoir, in situ monitoring, sampling and lab experiments of water columns were carried out at various sampling sites along the flow line in Wulixia Reservoir, Guangxi, China during early July, 2013. Results showed that: (1) The hydrochemical characteristics of study areas were controlled by the carbonate equilibrium system and the hydrochemical type of all water samples was HCO3-Ca + Mg. (2) The DIC concentration decreased gradually (DIC(Average) : from 1.03 to 0.78 mmol x L(-1)) and the delta13C(DIC) increased gradually (delta13C(DIC(Average) : from -10.21per thousand to -6.62 per thousand) from the reservoir end area to dam area. Meanwhile, with the depth increase in water column, the DIC concentration increased gradually (DIC(Average) : from 0.86 to 1.05 mmol x L(-1)) and the delta13C(DIC) decreased gradually (delta13C(DIC(Average) : from -7.88 per thousand to -13.39 per thousand) from the surface to the bottom of the reservoir. Possible reasons for these research results were found as follows: (1) Dissolution-precipitation process of carbonate substance could be inhibited by other processes such as biogeochemical processes, which played little role in delta13C(DIC) variations. (2) Thermal stratification existed in the study areas which could influence the distribution of DIC and delta13C(DIC) by affecting the distribution of plankton and its orientation and strength of metabolism process, and the extent of organic matter decomposition, and so on.
为了更深入了解岩溶水库中溶解无机碳的转化过程，2013年7月初在中国广西五里峡水库沿水流线的不同采样点进行了水柱的原位监测、采样和实验室实验。结果表明：（1）研究区域的水化学特征受碳酸盐平衡系统控制，所有水样的水化学类型均为HCO₃-Ca+Mg。（2）从水库末端区域到坝区，溶解无机碳（DIC）浓度逐渐降低（DIC（平均值）：从1.03降至0.78 mmol·L⁻¹），而δ¹³C（DIC）逐渐升高（δ¹³C（DIC（平均值）：从-10.21‰升至-6.62‰）。同时，随着水柱深度增加，从水库表层到底层，DIC浓度逐渐升高（DIC（平均值）：从0.86升至1.05 mmol·L⁻¹），而δ¹³C（DIC）逐渐降低（δ¹³C（DIC（平均值）：从-7.88‰降至-13.39‰）。这些研究结果的可能原因如下：（1）碳酸盐物质的溶解-沉淀过程可能受到生物地球化学过程等其他过程的抑制，这些过程对δ¹³C（DIC）变化的影响较小。（2）研究区域存在热分层现象，其可通过影响浮游生物的分布及其代谢过程的方向和强度、有机物分解程度等，进而影响DIC和δ¹³C（DIC）的分布。
