非岩溶水和硫酸参与溶蚀对湘南地区地下河流域岩溶碳汇通量的影响

发布时间：2019-01-08 14:31

【摘要】：研究非岩溶水和硫酸参与溶蚀对地下河流域岩溶碳汇通量的影响,有助于提高岩石风化碳汇通量估算精度,对于推进地质作用与全球气候变化研究意义重大。选取湘南北江上游武水河流域内4条典型地下河为对象,通过水化学对比分析,揭示硅酸盐岩风化对流域地下水化学的重要影响。运用Galy方法计算流域非岩溶地层中的硅酸盐岩风化消耗大气/土壤CO_2对岩石风化碳汇的重要贡献,并评价了H_2SO_4参与下碳汇通量的扣除比例。结果显示:(1)流域内有非岩溶地层的L01,L02地下河,Na~+,K~+和SiO_2浓度明显高于纯碳酸盐L03和L04地下河,非岩溶地层中的硅酸盐的风化对地下河水中K~+,Na~+,SiO_2浓度有一定贡献;(2)4条地下河的[Ca~(2+)+Mg~(2+)]/[HCO_3~-]当量比值为1.05~1.15,[Ca~(2+)+Mg~(2+)]/[HCO_3~-+SO_4~(2-)]的当量比值为0.99~1.08,Ca~(2+)+Mg~(2+)相对于HCO_3~-过量,过量的Ca~(2+)+Mg~(2+)与SO_4~(2-)相平衡,证实硫酸参与流域碳酸盐岩的溶蚀;(3)L01和L02地下河岩石风化消耗的CO_2通量中非岩溶地层中的硅酸盐风化消耗所占比例分别为3.36%和2.22%,而L03和L04地下河中硅酸盐风化消耗比例小于0.50%,表明有非岩溶地层存在的地下河流域,其岩石风化消耗的CO_2通量中硅酸盐风化消耗占有一定比例;(4)在考虑硫酸参与碳酸盐岩溶蚀时,4条地下河的碳汇通量分别扣除4.84%,4.52%,6.20%和9.36%。
[Abstract]:The study of the effect of non-karst water and sulfuric acid solution on karst carbon sink flux in underground river basin is helpful to improve the estimation accuracy of rock weathering carbon sink flux and is of great significance to the study of geological processes and global climate change. Four typical underground rivers in the Wushui River basin of the upper reaches of the southern and southern rivers of Hunan province were selected as the objects. The important influence of weathering of silicate rock on the groundwater chemistry of the basin was revealed through the comparative analysis of water chemistry. The Galy method is used to calculate the important contribution of atmospheric / soil CO_2 to the weathering carbon sink of silicate rock in non-karst strata of the basin, and the deduction ratio of carbon sink flux under the participation of H_2SO_4 is evaluated. The results are as follows: (1) the concentrations of Na~, K ~ and SiO_2 in L01U L02 underground river with non-karst strata in the basin are obviously higher than those in pure carbonate L03 and L04 underground rivers, and the weathering of silicate in non-karst strata has a significant effect on K ~, Na~ in underground river water. The concentration of SiO_2 contributed to some extent. (2) the equivalent ratios of [Ca~ (2) Mg~ (2)] / [HCO_3~-] for four underground rivers are 1.05U 1.15 and 0.991.08 for [Ca~ (2) Mg~ (2)] / [HCO_3~- SO_4~ (2-)], Compared with HCO_3~- excess, Ca~ (2) Mg~ (2) has excess Ca~ (2) Mg~ (2) and SO_4~ (2-) phase equilibrium, which proves that sulfuric acid is involved in the dissolution of carbonate rocks in the basin. (3) the CO_2 flux of rock weathering consumption in L01 and L02 underground rivers is 3.36% and 2.22% in non-karst strata, respectively, while the proportion of silicate weathering consumption in L03 and L04 underground rivers is less than 0.50%. The results show that the CO_2 flux of rock weathering consumption in underground river basin with non-karst strata accounts for a certain proportion of the consumption of silicate weathering. (4) considering the participation of sulfuric acid in carbonate rock dissolution, the carbon sink fluxes of the four underground rivers are deducted by 4.84% and 9.36% respectively.
【作者单位】：中国地质大学环境学院;中国地质科学院岩溶地质研究所;国土资源部广西岩溶动力学重点实验室;
【基金】：中国地质调查局地质调查项目“西江中下游岩溶峰林区1∶5万水文地质环境地质调查”(编号:121201107000150005) 国家自然科学基金项目“半干旱岩溶区溶蚀作用季节分异与影响机制”(编号:41302211)资助~~
【分类号】：P641.134

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