论文部分内容阅读
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%。
Studying the effect of non-karst water and sulfuric acid on the dissolution of karst carbon sink fluxes in underground river basins can help to improve the estimated accuracy of rock weathered carbon flux, which is of great significance for advancing geological study and global climate change research. Four typical underground rivers in the upper and lower reaches of the north and south of the Yangtze River in the north of Hunan Province are selected as the targets. Through comparative hydrochemical analysis, the important influence of silicate weathering on the groundwater chemistry in the basin is revealed. The Galy method was used to calculate the contribution of CO_2 to the weathered carbon sink in the weathering of silicate rocks in the non-karst layer of the drainage basin, and the deduction ratio of the carbon flux under the H_2SO_4 was evaluated. The results show that: (1) The concentrations of Na ~ +, K ~ + and SiO_2 in L01 and L02 underground rivers with non-karst stratum are significantly higher than those of pure carbonates L03 and L04 and non-karst stratum (2) [Ca ~ (2 +) + Mg ~ (2 +)] / [HCO_3 ~ -] equivalent of four underground rivers The ratio of Ca ~ (2+) + Mg ~ (2 +)] / [HCO3 ~ + SO4 ~ (2-)] was in the range of 1.05-1.15. (2 +) + Mg ~ (2+) with SO_4 ~ (2-) phase, confirming the involvement of sulfuric acid in the carbonate carbonate dissolution in the watershed; (3) ) L01 and L02 underground river rock weathered CO_2 flux in the non-karst formation of silicate weathering consumption accounted for 3.36% and 2.22% respectively, while L03 and L04 underground river silicate weathered consumption is less than 0.50% , Which indicates that there is a certain proportion of silicate weathered dissipation in the CO_2 fluxes consumed by rock weathering in the underground river basins where non-karst formations exist. (4) In consideration of the involvement of sulfuric acid in carbonate dissolution, the carbon of four underground rivers Huitong volume deducted 4.84%, 4.52%, 6.20% and 9.36% respectively.