论文部分内容阅读
岩石风化产生的碳汇是全球碳循环的重要组成部分,文中对清水江流域主要离子组成进行分析测定,通过主成分分析、化学物质平衡法和扣除法估算流域岩石风化速率及对大气CO_2的消耗量.结果表明,流域河水溶质主要来源于碳酸盐岩和硅酸盐岩风化,并以碳酸盐岩风化为主.碳酸盐、硅酸盐、大气CO_2对河水溶质的贡献率分别为58.28%、17.38%、17.74%.流域岩石化学风化速率为109.97 t·(km~2·a)~(-1),与乌江接近,高于全球流域均值.流域岩石风化对大气CO_2的消耗通量为7.25×10~5mol·(km~2·a)~(-1),岩石风化对大气CO_2的消耗量为12.45×10~9mol·a~(-1),其中,碳酸盐岩风化消耗量占63.13%,为7.86×10~9mol·a~(-1),硅酸盐岩风化消耗量占36.87%,为4.59×10~9mol·a~(-1).SO_4~(2-)、F~-、NO_3~-的相关分析及空间分布特征表明,人为活动对清水江流域河水溶质的影响不容忽视,其贡献率为4.87%.
The carbon sequestration caused by rock weathering is an important part of the global carbon cycle. In this paper, the main ion composition in the Qingshui River Basin is analyzed and determined. The rock weathering rate and the CO 2 consumption in the basin are estimated by principal component analysis, chemical balance and subtraction The results show that the river water solutes mainly come from weathering of carbonate rocks and silicate rocks and are mainly of carbonate weathering.The contribution of carbonates, silicates and atmospheric CO 2 to river water solutes are 58.28%, 17.38% and 17.74%, respectively.The chemical weathering rate of the basin is 109.97 t · (km ~ 2 · a) -1, which is close to the Wujiang River and higher than the mean value of the global basin. The amount of atmospheric CO_2 consumed by rock weathering was 12.45 × 10 ~ 9 mol · a -1, of which the carbonate weathering rate was 7.25 × 10 ~ 5mol · km ~ 2 · a -1. Accounting for 63.13%, accounting for 7.86 × 10 ~ 9mol · a ~ (-1). The weathering consumption of silicate rocks accounted for 36.87%, which was 4.59 × 10 ~ 9mol · a -1 .SO_4 ~ (2- ). The correlation analysis and spatial distribution of F ~ -, NO_3 ~ show that the influence of human activities on the water solutes in Qingshui River can not be neglected, and its contribution rate is 4.87%.