地球科学进展  2018 , 33 (2): 179-188 https://doi.org/10.11867/j.issn.1001-8166.2018.02.0179

研究论文

赤水河流域岩石化学风化及其对大气CO2的消耗

安艳玲12, 吕婕梅23, 罗进3, 吴起鑫23, 秦立2

1.贵州理工学院,贵州 贵阳 550002
2.贵州大学喀斯特环境与地质灾害防治重点实验室,贵州 贵阳 550025
3.贵州大学资源与环境工程学院,贵州 贵阳 550025

Chemical Weathering and CO2 Consumption of Chishuihe River Basin, Guizhou Province

An Yanling12, Lü Jiemei23, Luo Jin3, Wu Qixin23, Qin Li2

1.Guizhou Institute of Technology, Guiyang 550002, China
2.Key Laboratory of Karst Environment and Geohazard Prevention, Guizhou University, Guiyang 550025, China
3.College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China

中图分类号:  P512.12

文献标识码:  A

文章编号:  1001-8166(2018)02-0179-10

收稿日期: 2017-08-9

修回日期:  2017-12-1

网络出版日期:  2018-02-20

版权声明:  2018 地球科学进展 编辑部 

基金资助:  国家自然科学基金项目“典型喀斯特小流域/溪流系统水—气界面CO2释放研究”(编号:42603123)贵州省科技合作基金项目“赤水河流域水土流失过程氮、磷输出对水环境污染研究”(编号: 黔科合LH字[2016]7457号)资助

作者简介:

First author:An Yanling (1975-), female, Tongliao City, Inner Mongolia Autonomous Region, Professor. Research areas include water environment of river basin.E-mail:20170792@git.edu.cn

作者简介:安艳玲(1975-),女,内蒙古通辽人,教授,主要从事流域水环境研究.E-mail:20170792@git.edu.cn

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摘要

岩石风化碳汇是全球碳汇的重要组成部分,通过对赤水河流域水体主要离子组成进行测定,分析赤水河流域河水水化学特征及其岩石风化过程对大气CO2的消耗。结果表明:赤水河流域离子组成以Ca2+,Mg2+,HC和SO42-为主,河水总溶解性固体(TDS)含量均值为317.88 mg/L,高于全球流域均值(65 mg/L)。元素比值分析表明赤水河流域离子组成主要受岩石风化控制,其中碳酸盐岩风化为主导控制因素,碳酸盐岩、硅酸盐岩对河水溶质贡献率分别为70.77%和5.03%。人类活动和大气降水对流域河水溶质的贡献很小。流域岩石化学风化速率为126.716 t/(km2·a),高于黄河、长江、乌江及世界河流均值。流域岩石化学风化对大气CO2的消耗量为10.96×109 mol/a,岩石风化对大气CO2消耗速率为5.79×105 mol/(km2·a),与长江流域接近,高于黄河流域。

关键词: CO2消耗 ; 化学风化 ; 水化学 ; 赤水河

Abstract

Carbon sink produced during rock weathering is critical to global carbon cycles. In this work, we analyzed the major ion chemistry of the Chishuihe River Basin, and the major ion composition of the Chishuihe River system and the principal component analysis was applied for estimating the weathering rate and atmospheric CO2 consumption via the rock chemical weathering. The results demonstrated that the chemical composition of the river was dominated by Ca2+, Mg2+, HC and S. The average concentration(317.88 mg/L) of the total dissolved solids within the Chishuihe River was higher than the average value (65 mg/L) of world rivers. The Gibbs graph combining major ion element ratio analysis indicated that the catchment major ion composition mainly originated from rock weathering, primarily from carbonate weathering, sparsely from silicate weathering. Carbonate and silicate weathering contributed 70.77% and 5.03% separately to the dissolved loads. The anthropogenic and precipitation impact was limited. According to calculation based on principal component and the ion composition characteristics, the chemical weathering rate was 126.716 t/(km2·a), significantly higher than that of the Yellow River and Yangtze River, and also higher than the average rate of the global major rivers. The CO2 consumption flux based on annual average runoff was 10.96×109 mol/a, and the CO2 consumption rate by chemical weathering was 5.79×105 mol/(km2·a).

Keywords: CO2 consumption ; Chemical weathering ; Water chemistry ; Chishuihe River.

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安艳玲, 吕婕梅, 罗进, 吴起鑫, 秦立. 赤水河流域岩石化学风化及其对大气CO2的消耗[J]. 地球科学进展, 2018, 33(2): 179-188 https://doi.org/10.11867/j.issn.1001-8166.2018.02.0179

An Yanling, Jiemei, Luo Jin, Wu Qixin, Qin Li. Chemical Weathering and CO2 Consumption of Chishuihe River Basin, Guizhou Province[J]. Advances in Earth Science, 2018, 33(2): 179-188 https://doi.org/10.11867/j.issn.1001-8166.2018.02.0179

河流作为全球碳循环的重要组成部分,是全球碳循环的一个关键环节[1]。河流水化学特征的研究是区域和全球环境问题研究极具代表性的研究热点[2,3]。岩石化学风化过程中能够吸收大气CO2产生巨大的碳汇,达到减少大气CO2的效果[4]。而岩石化学风化消耗的CO2量可以通过流域水化学及河流径流量估算[5]。研究表明,每年约有0.7×109 t来自大气CO2的碳经陆地化学风化作用通过河流转移到海洋中[4,6~8],流域碳输送是全球碳循环研究的重要组成内容之一,对其岩石风化进行大气CO2吸收的研究对估算河流在全球碳循环研究中的作用具有重要意义。

赤水河流域是唯一鱼类组成与三峡库区鱼类大体一致的河流,也是长江上游唯一干流未建坝的一级支流,其生态环境保护具有重要意义。赤水河流域上游为典型的喀斯特区域,中下游以丹霞地貌为主,流域的地质背景、土壤类型、气候水文条件、植被分布、水土流失和区域开发等特点具有明显的地带性分布,为研究分析自然条件和人为活动对流域水化学特征的影响提供了良好基础。而目前对赤水河流域的研究主要侧重于流域水化学[9,10]、流域水质[11]及重金属污染等方面,尚没有关于流域岩石风化对大气CO2的吸收进行估算的研究。鉴于赤水河流域特殊的地质背景、区域经济特点以及重要的生态保护意义,本文选取赤水河作为研究对象,分析赤水河流域主要水化学特征,并根据流域主要离子组成特征估算化学风化对河水溶解物质的贡献率及对大气CO2的吸收,以期对我国喀斯特地区(碳酸盐岩)和丹霞地貌地区(硅酸盐岩)的河流水化学信息进行补充,并为赤水河流域生态环境的保护与建设及全球碳循环研究提供基础数据。

1 研究区概况

赤水河是长江干流上游右岸的一级支流,因河流含沙量高、水色赤黄而得名。地处云贵高原与四川盆地接壤处,地势南高北低,西南临乌蒙山脉,东为大娄山脉、北接四川盆地。流域发源于云南省镇雄县的北部,在四川省合江县汇入长江,源头至茅台为上游,茅台至赤水为中游,赤水以下为下游。赤水河全流域面积18 932.21 km2,干流全长436.5 km,川、滇、黔3省各占流域面积的31%,10%和59%。流域属中亚热带季风气候区,流域多年平均年降水量为800~1 200 mm,降水量受地理环境的影响,中游至下游有递增的趋势。流域水系如图1所示。

图1   赤水河流域水系图

Fig.1   The river system distribution of Chishui River Basin

赤水河流域地层出露丰富,上中游地层主要以寒武系、奥陶系、志留系、二叠系、三叠系及侏罗系的灰岩类和白云岩类为主,其次有泥岩、砂页岩和含煤岩组,玄武岩亦有相当数量出露。下游地层单一,构造简单,主要为侏罗—白垩系的紫红色粉砂岩和泥岩,另有少量油页岩,仅在南部边缘有少量碳酸盐岩石分布在分水岭地带。

2 样品的采集与分析

本次研究采样涉及赤水河流域全流域,自云南省镇雄县至四川省合江市(采样点如图1所示)。其中枯水期河水样品,采集于2012年12月,共采集水样38个,其中干流水样18个,支流水样18个,长江样品2个。丰水期水样采集于2013年8月,共采集水样41个,其中干流水样20个,支流水样19个,长江样品2个。河水pH值、温度、电导率等水质参数采用WTW便携式多参数测定仪现场测定,HC用0.025 mmol/L HCl滴定法现场测定,每个样品滴定3次,每次盐酸使用体积差在0.1 mL以内。样品采集当天用0.45 μm醋酸纤维滤膜过滤后分为2个部分,一部分过滤水样中加入超纯HCl酸化至pH<2用于测定阳离子(K+,Na+,Ca2+,Mg2+),另一部分过滤水样直接保存用于测定阴离子(S O42-,Cl-,N,F-),以上样品均密封保存。样品带回实验室后,用ICS-1100型离子色谱仪(Dionex,USA)测定,样品测试精度在5%以内。

3 结果与讨论

3.1 河水主要离子组成特征分析

赤水河流域水体温度变化较大,为8.6~30.9 ℃,自上游到下游水体温度逐渐增高,与赤水河流域的区域气候差异表现一致。流域水体pH平均值为8.25,总体偏弱碱性。流域丰水期总溶解性固体(Total Dissolved Solids,TDS)为180.52~531.35 mg/L,均值为297.22 mg/L,枯水期TDS为85.95~614.20 mg/L,均值为317.88 mg/L,高于世界流域均值(65 mg/L[12])。受丰水期降雨稀释的影响,TDS丰水期低于枯水期。

赤水河流域河水水化学组成以Ca2+,Mg2+,HC和S为主,部分支流河水的水化学组成表现分别以Ca2+,Na+,HC和S以及Ca2+,Na2+,S O42-,HC为主。其中,流域干流河水阳离子含量表现为Ca2+>Mg2+>Na+>K+,Ca2+和Mg2+为主要阳离子,枯水期占总阳离子的85%以上,其中Ca2+占65%以上;丰水期Ca2+和Mg2+占总阳离子的77%~94%以上,其中Ca2+占58%以上。干流河水阴离子含量多表现为HC>S O42->N>Cl-,阴离子以HC和S为主,枯水期占阴离子总量的76%~96%,其中HC占47%~77%;丰水期占阴离子总量的86%~93%,其中HC占54%~75%。

3.2 河流水化学影响因素分析

3.2.1 大气降水及人类活动的影响

Cl-是雨水的主要成分,在大气降水对河水化学影响的研究中,常选择Cl-作为参照元素。通过海盐校正的方法,采用Cl-与标准海水中其他离子浓度的比值进行校正,其中,Na+/Cl-=0.86,K+/Cl-= 0.02,Ca2+/Cl-= 0.04,Mg2+/Cl-= 0.21,S/Cl-= 0.11[13]。赤水河流域K+,Na+,Ca2+,Mg2+和S的平均浓度分别为0.25,0.05,0.45,1.46和0.84 mmol/L,估算得出赤水河流域大气降水对河水溶解物质的贡献率为0.48%~0.73%,低于世界流域均值3%[14],可见,海盐输入对河水溶质的贡献很小。

Gaillardet等[15]统计了世界上的61条大河,利用TDS和Cl-/Na+摩尔浓度比作为判断人为活动对河流影响的主要参数。其研究结果显示,受人为活动污染影响严重的河流一般具有2个特点:河水的TDS>500 mg/L,且Cl-/Na+摩尔浓度比高于海盐比1.17。将赤水河流域河水样品点绘制于Na+/Cl-与TDS关系图(图2)中,可以看出赤水河流域河水TDS值均低于500 mg/L,Na+/Cl-值小于1.17,由此可见,赤水河流域受人为活动的影响较小。

图2   赤水河流域河水Na+/Cl-与TDS关系图

Fig.2   Plots of Na+/Cl- vs. TDS for the river water of Chishui River Basin in dry and wet seasons

3.2.2 岩石风化的影响

为了确定影响赤水河流域水化学组成的控制因素,将赤水河干流、支流和长江的样品绘制于Gibbs图上(图3),如图3所示,赤水河流域水样的Na+/(Na++Ca2+)值多集中在0.1~0.3,丰水期与枯水期基本吻合,数据点大部分落在岩石风化控制区,说明赤水河流域水化学主要受岩石风化影响。相对赤水河汇入长江河口处的长江样品,赤水河样品Na+/(Na++Ca2+)值相对偏低,主要原因是赤水河Na+在阳离子中比例更低,这也表明赤水河流域岩石风化作用与长江流域存在差异。

在阳离子三角图(图4图5)中,研究区丰水期和枯水期的样品点主要分布在Ca2+-Mg2+线上,靠近Ca2+一端,反映了强烈的碳酸盐岩风化对流域风化的影响。阴离子三角图(图4图5)中,研究区样品点分布于HC-S O42-线上,反映了HC和S是流域主要风化介质。如图5所示,流域干流样品分布较为集中,相对于干流样品,支流样品分布较为分散,反映了不同的小流域,由于地质背景、生态环境、岩性的不同,具有明显不同的离子组成特征。

与我国长江、乌江、黄河和赣江等流域离子组成相比(图4图5),赤水河流域阴阳离子组成与主要受富含碳酸盐矿物的沉积岩及蒸发结晶作用控制的黄河流域以及主要受到硅酸盐岩风化控制的赣江存在明显差异,与长江流域较为相似,而与同处喀斯特地区的乌江流域化学组成一致,表现出典型喀斯特地区河流特征。

图3   赤水河流域河水Gibbs图

Fig.3   The Gibbs plot of the river water of Chishui River Basin

图4   赤水河丰水期河水样品主要阳、阴离子三角图

Fig.4   Ternary diagrams of anions and cations in river water of Chishui River Basin in wet season

图5   赤水河枯水期河水样品主要阳、阴离子三角图

Fig.5   Ternary diagrams of anions and cations in river water of Chishui River Basin in dry season

通过Mg2+/Na+-Ca2+/Na+及HC/Na+-Ca2+/Na+的关系图(图6图7)可以看出,赤水河干流的数据点靠近碳酸盐岩控制区,表明赤水河干流河水离子组成主要受到碳酸盐岩风化控制。相对于干流,上游、中游的支流数据点多落在靠近碳酸盐岩控制区,而下游硅酸盐地区的支流河水数据点则较靠近硅酸盐岩控制区,表明上、中、下游的支流受到不同类型的岩石风化控制,中、上游地区支流主要受到碳酸盐岩风化控制,而下游地区支流主要受到硅酸盐岩风化控制。同时下游河口处长江河水的数据点落点靠近硅酸盐岩控制区,表明河口处长江受硅铝质岩影响程度大于研究区河水样品。

图6   赤水河流域丰水期Mg2+/Na+-Ca2+/Na+及HC/Na+-Ca2+/Na+关系图

Fig.6   Plots of Ca2+/Na+ vs. Mg2+/Na+, and Ca2+/Na+ vs. HC/Na+ ratios for the river water of Chishui River Basin in wet season

图7   赤水河流域枯水期Mg2+/Na+-Ca2+/Na+及HC/Na+-Ca2+/Na+关系图

Fig.7   Plots of Ca2+/Na+ vs. Mg2+/Na+, and Ca2+/Na+ vs. HC/Na+ ratios for the river water of Chishui River Basin in dry season

地表岩石的化学风化反应介质主要为碳酸和硫酸[16,17],H2CO3风化碳酸盐岩2(Ca2++Mg2+)/HC的浓度值为1,H2SO4风化碳酸盐岩2(Ca2++Mg2+)/HC的浓度值为2,2S O42-/HC浓度比值为1[18,19]。近些年对西南喀斯特流域地表水化学计量学、S O42-的δ34S和溶解无机碳(DIC)的δ13C分析发现,硫循环中形成的硫酸广泛参与了流域碳酸盐矿物的溶解和流域侵蚀[3,20~22]。在赤水河流域,河水样品2(Ca2++Mg2+)/HC浓度值在丰水期和枯水期均处于1∶ 1等值线上方(图8),其中丰水期为1.29~2.25;枯水期为1.25~5.16,赤水河流域水样分布于碳酸风化碳酸盐和硫酸风化碳酸盐岩2个端元组成之间,表明碳酸和硫酸均是流域碳酸盐岩风化的重要介质。

3.3 岩石风化碳汇效应

3.3.1 主成分分析

为了探讨流域不同岩石风化类型对河水溶质的影响,对河水中来源于岩石风化的离子组成做主成分分析(PCA)[23~28],通过最大正交旋转法进行主成分分析和因子分析,得出的因子载荷见表1。选择特征值大于1且累计贡献率大于87.161%的前3个主成分为因子数目,可认为信息量无损失。对初始因子进行25次的正交旋转,得出旋转后的载荷矩阵,结合各因子的方差贡献率得出各成分的得分系数矩阵。提取得到的3个主因子累积贡献率达84.734%(表1),第1因子对方差的贡献率为45.586%,主要与HC和Mg2+相关;第2因子对方差的贡献率为25.775%,主要与S O42-和C相关;第3因子对方差的贡献率为13.374%,主要与SiO2,Na+和K+相关。

图8   赤水河流域2(Ca2++Mg2+)/HC与2SO42-/HC当量比值的关系

Fig.8   Plots of HC vs. 2(Ca2++Mg2+), and 2SO42- vs. HC for the river water of Chishui River Basin in dry and wet seasons

不同的岩石风化类型,其风化产物具有各自不同的特点。其中碳酸盐类岩石风化,主要生成Ca2+,Mg2+和HC,硅酸盐类岩石风化产生Na+,K+,Ca2+,Mg2+和SiO2,流域并没有明显蒸发岩出露,在此不对蒸发岩进行讨论分析。如表1所示,第1因子与HC和Mg2+表现出较大的相关性,第二因子与S O42-和Ca2+表现出较大的相关性,结合考虑第1因子和第2因子,发现碳酸与硫酸共同参与的碳酸盐岩风化能很好地解释该情况,其累积对方差的累积贡献率为71.361%。第3因子主要与SiO2,Na+和K+相关,代表硅酸盐岩风化对流域河水的影响(主要来自下游硅酸盐岩地区)。通过因子分析可以对河水主要离子来源进行粗略估算,第1因子、第2因子和第3因子分别代表了碳酸盐岩风化、硫酸参与碳酸盐岩风化和硅酸盐类岩石风化的3种过程。

表1   赤水河流域河水主成分因子分析载荷矩阵

Table 1   Component loadings of the Chishui River Basin water chemistry calculated in terms of the principal component analysis

变量因子1因子2因子3公共性方差
Na+0.7440.3620.2210.733
K+0.9160.0640.1090.855
Mg2+0.8180.3540.0950.802
Ca2+0.4230.8580.1480.936
Cl-0.7880.3050.0280.714
S0.1950.959-0.0120.957
HC0.8580.2260.0300.787
SiO20.1190.0600.9880.994
方差贡献率/%45.58625.77513.37484.734

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将每个变量因子载荷的平方除以公共性方差即为每类岩石的溶解对各变量的相对方差贡献率。根据表1,基于各因子载荷,从方差的角度估算得出3类岩石风化及大气CO2对各离子的相对贡献率。其中Mg2+因子总提取率为0.802,则碳酸盐岩风化对赤水河河水中Mg2+的相对方差贡献率为83.4%,硫酸参与碳酸盐岩风化对赤水河河水中Mg2+的相对方差贡献率为15.6%,硅酸盐岩风化对赤水河河水中Mg2+的相对方差贡献率为1.13%。Ca2+因子总提取率为0.936,则碳酸盐岩风化对赤水河河水中Ca2+的相对方差贡献率为19.12%,硫酸参与碳酸盐岩风化对赤水河河水中Ca2+的相对方差贡献率为78.65%,硅酸盐岩风化对赤水河河水中Ca2+的相对方差贡献率为2.34%。S O42-因子总提取率为0.957,则碳酸盐岩风化对赤水河河水中S O42-的相对方差贡献率为3.97%,硫酸参与碳酸盐岩风化对赤水河河水中S O42-的相对方差贡献率为96.10%。SiO2因子总提取率为0.994,流域河水中SiO2全部来自于硅酸盐岩风化。需要进行说明的是,Na+,K+和Cl-并不是碳酸盐岩风化的特征产物,但在因子分析中却与碳酸盐风化表现出了较好的相关性。由于流域河水中,这3种离子的含量都非常低,初步认为该部分Na+,K+和Cl-来源于大气、人为活动或硅酸盐岩风化,并对其进行修正。

研究表明,碳酸盐类岩石风化,其HC只有一半来自大气和土壤CO2[29];硅酸盐类岩石风化,所有HC均来自大气和土壤中的CO2;硫酸参与的碳酸盐岩风化,主要生成Ca2+,Mg2+,HC和S O42-,所有HC均来自碳酸盐[22]。赤水河流域河水中HC因子总提取率为0.787,碳酸盐岩风化对赤水河河水中HC的相对方差贡献率为93.54%,硫酸参与碳酸盐岩风化对赤水河河水中HC的相对方差贡献率为6.46%。计算得出,河水中53.23%的HC来自碳酸盐本身,46.77%来自大气CO2

根据各岩石风化类型对赤水河流域各离子的贡献率及河水中各离子浓度计算得出(表2),碳酸盐岩风化对河水溶质的贡献率为70.77%,其中碳酸溶解的碳酸盐岩风化对赤水河流域河水总溶解物质的贡献率为27.70%,硫酸参与的碳酸盐岩风化贡献率为43.07%,高于长江、黄河、乌江及世界流域平均值;硅酸盐岩风化对研究区河水总离子贡献率为5.03%,低于长江、世界平均值,高于黄河、乌江;大气CO2对研究区河水总离子贡献率为20.10%,高于长江、黄河,低于乌江及世界河流均值;人为活动或大气降水对流域总离子贡献4.10%。

表2   不同岩性和大气对赤水河河水化学组成物质的贡献率与世界、国内流域平均值的比较(单位:%)

Table 2   Compare Chishui River Basin chemistry weathering rates with other rivers in the world and China(unit:%)

来源碳酸盐硅酸盐蒸发岩大气CO2其他因素
赤水河70.775.0320.104.10
长江46.912.913.119.62.65
黄河41.93.2344.710.2
乌江32.91.6541.823.6
世界河流351511372.0

注:数据来自参考文献[30,31]

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3.3.2 化学风化速率及对大气CO2的消耗

化学风化率通常指单位面积内来自于岩石风化的河流溶解载荷的量,通常用化学风化速率来衡量化学风化作用强弱,利用河水的化学通量[X]silicate和[X]carbonate可以估算流域碳酸盐和硅酸盐的化学风化速率[4],对于受到大气降水和人类活动影响的河流,在估算化学风化速率时要先对这部分来源进行扣除[31]。大气对河水的输入还表现在岩石风化过程中有大气和土壤CO2与水作为反应介质参与进去,最终以HC的形式进入河水中,而这部分大气中的CO2本身并不来自岩石,所以在计算化学风化速率时应将这部分HC排除在外。李晶莹[31]通过对中国主要流域盆地的化学风化率进行研究,结果显示由于河水中HC的浓度通常很高,大气CO2对河水中HC的贡献率常常占相当大的比例,如东江河水中的HC全部来自于大气CO2,转化为河水中的HC对河水溶解质贡献率高达30%。

根据对研究区河水的主成分因子分析,认为研究区主要的岩石风化类型以碳酸盐岩风化为主,并存在少量硅酸盐岩风化。硫酸显著地参与了碳酸盐岩的风化过程。流域主要化学风化过程如下式所示:

(C a1-xMgx)CO3+CO2+H2O→(1-x)Ca2++xMg2++2HC →(Ca1-xMgx)CO3+CO2+H2O, (1)

2(1-x)Ca2++2xMg2++2HC+S O42-→(Ca1-xMgx)CO3+(1-x)Ca2++xMg2++S O42-+ CO2+H2O。 (2)

结合考虑赤水河流域的情况,本文将流域化学风化率公式进行优化,计算公式如下:

CDR=([Ca2+]carb+[Mg2+]carb+1/2[HC]carb+[Ca2+]carb+[Mg2+]carb +[HC]carb

+2[S O42-]carb+[K+]sil + [Na+]sil+[Ca2+]sil+[Mg2+]sil+[SiO2]sil+[S O42-]sil)×Q/A, (3)

式中:CDR为校正后的流域化学风化率(t/(km2·a));[X]carb,[X]sil分别为扣除大气降水及人为影响输入后的碳酸盐岩、硅酸盐岩对河流离子X的贡献浓度(10-6 t/m3);Q为河流多年平均径流量(m3/a);A为流域面积(km2)。

赤水河流域河口多年平均流量为309 m3/s,流域面积为18 932.214 km2,利用各类型岩石风化风化对河水的相对贡献率(表2),估算出赤水河流域的平均化学风化率为126.716 t/(km2·a)。远高于黄河流域的平均化学风化率39.29 t/(km2·a)、世界流域平均风化率36 t/(km2·a),长江流域多年平均化学风化率61.58 t/(km2·a)及乌江平均多年化学风化率108.3 t/(km2·a)[31]。赤水河流域与乌江流域较高的化学风化率表明喀斯特地区的强烈化学风化作用对其所属地区河流的水化学的组成有决定性影响,酸沉降等溶解了地层中的硫化物形成的硫酸参与了流域碳酸盐矿物的溶解的同时加速了流域化学风化速率。

赤水河流域HC浓度均值为2.17 mmol/L,根据水化学—径流计算方法[32],估算得出流域大气CO2消耗速率为5.79×105 mol/(km2·a),与长江接近,低于乌江、西江,高于黄河流域、赣江流域、东江,远高于全球流域平均值(表3),流域大气CO2的年消耗量为10.96×109 mol。

表3   赤水河流域岩石化学风化碳汇与其他地区河流比较

Table 3   Chishuihe River Basin rocks chemical weathering carbon sink comparing with other rivers in the world and China

河流大气CO2消耗速率
/(×105 mol/(km2·a))
大气CO2的消耗量
/(×109 mol/a)
赤水河5.7910.96
长江[15,33]6.111 104.00
乌江[31]9.0279.28
黄河[33]1.44108.00
赣江[31]4.0934.13
西江[31]8.32282.90
东江[34]4.84~4.937.65~7.79
全球流域平均值[15]2.4624 000.00

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4 结论

赤水河流域pH平均值为8.25,总体偏弱碱性。TDS处于85.95~614.20 mg/L,均值为317.88 mg/L,TDS丰水期略低于枯水期。流域水化学组成以Ca2+,Mg2+,HC和S O42-为主,TDS与Na+/(Na++Ca2+)、Cl-/(Cl-+HC)比值图分析表明赤水河河水溶质表现为主要受到岩石风化影响。流域主要元素比值分析表明流域主要受到碳酸盐岩风化影响,其次为硅酸盐岩。碳酸盐岩风化对河水溶质的贡献率为70.77%,高于世界平均值及长江、乌江流域。硅酸盐岩对河水溶质的贡献率为5.03%,远低于世界河流平均值。

根据流域河水主要离子浓度及主成分分析结果计算得出赤水河流域的化学风化率为126.716 t/(km2·a),高于黄河、长江、乌江及世界河流平均值。根据流域HC浓度及多年平均径流量计算得出赤水河流域岩石化学风化对大气CO2的消耗量为10.96×109 mol/a,流域岩石风化对大气CO2消耗速率为5.79×105 mol/(km2·a),与长江流域较为接近,高于黄河流域。

The authors have declared that no competing interests exist.


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[J]. 长江流域资源与环境, 2014, 23(10): 1 472-1 478.]

DOI      URL      [本文引用: 1]      摘要

赤水河是长江上游唯一没有筑坝的一级支流,是长江上游珍惜特有鱼类自然保护区,被誉为美酒河、美景河、英雄河和生态河,具有重要的保护价值。选取枯水期赤水河为研究对象,进行全流域的采样与分析,总计37个采样点。运用箱线图直观表现出各个水质指标的分布情况,并运用综合水质标识指数法得出赤水河枯水期的水质类别,进行水质定性评价,然后根据水质标识指数的变化分析了赤水河干流的水质空间分布变化特征。结果表明:赤水河水质总体较为良好,流域总体水质标识指数X1.X2为1.6;干流的水质标识指数X1.X2为1.5;各个支流来看,桐梓河、古蔺河和习水河的水质标识指数X1.X2分别为1.5、1.7和1.5,均为Ⅰ类水,水质与干流差别不大,但是盐津河污染较为严重,X1.X2为3.2,为Ⅲ类水,特别是TP浓度达到0.6mg/L。各个采样点水质评价结果均为优秀(源头除外)。另外城镇污水对赤水河的影响不容忽视,要提高警惕,限制或减少城镇污水的排放。
[12] Meybeck M, Helmer R.

The quality of rivers: From pristine stage to global pollution

[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 1989, 75(4): 283-309.

DOI      URL      [本文引用: 1]      摘要

River water quality is highly variable by nature due to environmental conditions such as basin lithology, vegetation and climate. In small watersheds spatial variations extend over orders of magnitude for most major elements and nutrients, while this variability is an order of magnitude lower for major basins. A standard river water for use as reference is therefore not applicable. As a consequence natural waters can possibly be unfit for various human uses, even including drinking. The Water Quality (WQ) concept has greatly evolved since the beginning of the century in accordance with expanding water uses and analytical developments. Even in well developed countries the dissolved heavy metal measurements in rivers are not very reliable while dissolved organic micro-pollutants are even rarely analysed routinely. Major WQ problems have been identified according to river basin size, including organic pollution, salinity, total suspended solids, heavy metals, eutrophication, nitrate, organic micro-pollutants, acidification. They generally occurred in this order over a period of about 100 years in the industrialized countries. Historical records of WQ are rare but can be established indirectly through studies of lake sediments. When proper control action is taken at an early stage, numerous examples of WQ recovery have been found in rivers for most of the common pollution problems. Future WQ problems will mostly derive from mine tailings and toxic waste disposal in both developed and developing countries, industrial accidents and organic micropollutants which emerge faster than our analytical capacities. The newly industrializing countries will face all the above-mentioned problems within a very short time period without having the means to cope with them one at a time. River studies point out the global alteration of the biogeochemical cycles of many major elements and nutrients (S, Na, K, N, P). For heavy metals such as lead, present estimates of global river loads emphasize the role of interim storage on land, thus delaying downstream pollution problems.
[13] Grosbois C, Négrel P, Fouillac C, et al.

Dissolved load of the Loire River: Chemical and isotopic characterization

[J]. Chemical Geology, 2000, 170(1/4): 179-201.

DOI      URL      [本文引用: 1]      摘要

The aim of this study is to describe the mixing model in order to estimate the contribution of each component. Finally, specific export rates in the upper Loire watershed were evaluated close to 12 t year 611 km 612 for the silicate rate and 47 t year 611 km 612 for the carbonate rate.
[14] Gaillardet J, Dupre B, Allegre C J, et al.

Chemical and physical denudation in the Amazon River Basin

[J]. Chemical Geology, 1997, 142(3): 141-173.

DOI      URL      [本文引用: 1]      摘要

We present major and trace element data on the suspended and dissolved phases of the Amazon River and its main tributaries. The Sr isotopic composition of the dissolved load is also reported. Special attention is paid to the abundances of REE and to their fractionation between the dissolved and suspended phase. The rivers of the Amazon Basin are among the richest in dissolved REE and are similar to the rivers of the Congo system. However a greater range of fractionation between LREE and HREE is reported here. At a global scale the rivers have intermediate patterns between those of the Congo system and those of high pH rivers such as the Indus and Mississippi rivers. Only few elements (Rb, U, Ba, K, Na, Sr and Ca) are mobilized by silicate weathering. These elements are strongly depleted in the suspended phase with respect to upper continental crust. In the dissolved load, these elements are controlled by atmospheric inputs and the weathering of the main lithologies. We propose a model based on mass budget equations, that allow the proportions derived from the different sources to be calculated. As a consequence silicate, carbonate and evaporite weathering rates can be estimated as well as the consumption of CO 2 by weathering of each of these lithologies. Physical weathering rates can be estimated by two complementary approaches. On the one hand, the multi-year average of suspended sediments yields can be used to estimate physical denudation. On the other hand, we have developed a steady-state model of erosion that allows us to calculate physical erosion rates on the basis of the dissolved load of rivers. A mean crustal composition is assumed in this model for the rock sources of the drainage basins. Comparison of the rates predicted by the model to the observed rates shows good agreement for the lowland rivers, but a strong discrepancy for the rivers derived from the Andes. Andean rivers (Solimoes, Madeira and Amazon) have observed sediment yields much greater than those predicted according to the steady-state model of chemical and physical weathering. Two interpretations can account for this inconsistency. The first is that these rivers are not in steady state and hence that the soils are being destroyed. The second requires that the local continental crust is different from the average continental crust of Taylor and McLennan, and contains a large proportion of sedimentary rocks. Using the measured sediment yields, and assuming a steady state, we can estimate the amount of sediment recycling for each drainage basin. For the Amazon at Santarem, we find that at least 25% of the mass of the upper continental crust of the Amazon drainage basin is constituted of recycled material.
[15] Gaillardet J, Dupré B, Louvat P, et al.

Global silicate weathering and CO2 consumption rates deduced from the chemistry of large rivers

[J]. Chemical Geology, 1999, 159(1): 3-30.

DOI      URL      [本文引用: 3]      摘要

The main problem associated with the study of silicate weathering using river dissolved load is that the main control of solute chemistry is lithology and that all rivers are influenced by carbonate and evaporite weathering. In this paper, newly compiled data on the 60 largest rivers of the world are used to calculate the contribution of main lithologies, rain and atmosphere to river dissolved loads. Technically, an inverse method is used to solve a model containing of a series of mass budget equations relating river concentrations to chemical weathering products and atmospheric inputs. New estimates of global silicate weathering fluxes and associated CO 2 consumption fluxes are given. The role of basalt weathering on oceanic islands and volcanic arcs is emphasized. For each large river, an attempt is made to calculate chemical weathering rates of silicates per unit area. Only relative chemical weathering rates can be calculated. The relationships between the chemical weathering rates of silicates and the possible controlling parameters are explored. A combined effect of runoff-temperature and physical denudation seems to explain the variability of modern silicate chemical weathering rates. The results of this study highlight the coupling between the physical and the chemical processes of silicate weathering. Only an active physical denudation of continental rocks seems to be able to maintain high chemical weathering rates and significant CO 2 consumption rates.
[16] Lerman A W.

CO2 and H2SO4 consumption in weathering and material transport to the ocean, and their role in the global carbon balance

[J]. Marine Chemistry, 2007, 106(1): 326-350.

DOI      URL      [本文引用: 1]      摘要

Consumption of CO 2 in mineral weathering reactions is one of the major fluxes in the global carbon cycle that drives the weathering and transport of its products by surface water from land to the ocean. In the weathering cycle, carbon dioxide, as an acid derived directly from the atmosphere and(or) remineralization of organic matter in soil, is supplemented by small, but perhaps regionally important, amounts of sulfuric acid forming in the oxidation of pyrite (FeS 2 ). Reactions of dissolved CO 2 and H 2 SO 4 with carbonate and silicate minerals in continental sediments and crystalline crust produce the bicarbonate ion HCO 3 61 and release metal cations, such as the four major cationic components of river water, Ca 2+ , Mg 2+ , Na + , and K + , and dissolved silica to solution. Depending on the reactions that may either only consume CO 2 or uncommonly also produce it, a general relationship describing the CO 2 consumption by weathering reactions with carbonate and silicate minerals is a weathering potential ψ 02=02(net CO 2 consumed)02/02(HCO 3 61 produced). The lower values of this ratio, about 0.54, are for carbonate rocks and evaporites, about 0.75 for shales and sandstones, and 1 for the crystalline igneous continental crust. In an average world river (of which there is more than one estimate of chemical composition), the mass proportions of the main cations and anions differ from those in the weathering source that consists of the sediments and part of the continental crust because of the differences in mineral solubilities and dissolution rates. A dissolution model of a weathering source that consists of 63wt% average sediment and 37 wt% upper continental crust gives the concentrations of the major dissolved constituents in an average river that agree very well with the range of composition given by other investigators. This dissolution model also provides an average CO 2 consumption potential of ψ 02=020.72 and a sequence of relative stability or order of persistence in the weathering of the mineral constituents of the sedimentary carbonate, silicate, and evaporitic rocks, and the crustal silicates. The CO 2 consumption rate translates into a weathering flux of about 2202×0210 12 mol C/yr, derived mainly from soil–atmosphere CO 2 that forms by decomposition of organic matter in soils. Anthropogenic emissions of SO 2 to the atmosphere, as projected for the future and at the upper bound of the projection, may provide H 2 SO 4 to the continental surface that is 3 to 5 times greater than the natural H 2 SO 4 production by the oxidation of pyrite in sediments. The higher input rates of H 2 SO 4 may increase the dissolved ionic solid concentrations in river waters by about 13%, without significantly affecting the CO 2 consumption in weathering. In the global carbon cycle, the CO 2 uptake in weathering is comparable to other interreservoir fluxes in the atmosphere–land–ocean system.
[17] Xie Chenji, Gao Quanzhou, Tao Zhen.

Review and perspectives of the study on chemical weathering and hydrochemistry in river basin

[J]. Tropical Geography, 2012,32(4): 331-337,356.

Magsci      [本文引用: 1]     

[解晨骥,高全洲,陶贞.

流域化学风化与河流水化学研究综述与展望

[J]. 热带地理, 2012,32(4): 331-337,356.]

DOI      URL      Magsci      [本文引用: 1]      摘要

工业革命以来大气CO2浓度不断上升,其源汇机制和时空变化成为学界关注的焦点。岩石特别是硅酸盐类岩石的化学风化是全球生物地球化学循环的重要碳汇。控制化学风化速率的因素较为复杂,各因素作用的机理和重要性还不完全明确。源于人类排放的H2SO4普遍参与到化学风化过程中,这加快了流域化学风化的速率,但这一过程对碳汇效应的影响机理尚缺乏足够的研究。当前河流水化学研究中用来判断河水化学类型及离子来源的方法可分为定性和定量两类,前者有Gibbs图法、三角图法和端元图法等;后者包括质量平衡法和同位素示踪法等。目前对影响流域化学风化速率因素的研究多侧重于对单一环境要素与风化速率之间响应关系的分析,在今后的研究中有必要介入更为严谨的数理统计方法;有关硫酸参与流域化学风化过程的研究成果还较少,随着酸雨现象日趋严重,这一课题的重要性日渐突出;在短时间尺度上碳酸盐岩化学风化的碳汇效应不可忽视,今后应加强对其研究。
[18] Li Jun, Liu Congqiang, Li Longbo, et al.

The impacts of chemical weathering of carbonate rock by sulfuric acid on the cycling of dissolved inorganic carbon in Changjiang River water

[J]. Geochimica, 2010, 39(4): 305-313.

[本文引用: 1]     

[李军,刘丛强,李龙波,.

硫酸侵蚀碳酸盐岩对长江河水DIC循环的影响

[J]. 地球化学, 2010, 39(4): 305-313.]

URL      [本文引用: 1]      摘要

对长江及其主要支流河水水化学和溶解无机碳(DIC)同位素组成(δ13CDIC)进行了研究。河水阳离子组成以Ca2+、Mg2+为主,阴离子以HCO 3-、SO42-为主,水化学组成主要受流域碳酸盐岩矿物的化学侵蚀控制。DIC含量为0.3~2.5 mmol/L,从上游到河口逐渐降低。δ13CDIC值为-12.0‰~-3.4‰,与DIC含量具有相似的变化趋势。H2CO3溶解碳酸盐岩是控制河水DIC来源及其δ13CDIC组成的主要机制。H2SO4溶解碳酸盐岩加剧了流域碳酸盐岩的化学侵蚀,一方面导致了河水的DIC含量增加,另一方面也使河水的δ13CDIC值升高。
[19] Li Siyue, Lu X, He Min, et al.

Major element chemistry in the upper Yangtze River: A case study of the Longchuanjiang River

[J]. Geomorphology, 2011, 129(1/2): 29-42.

DOI      URL      [本文引用: 1]      摘要

78 Water chemistry was dominated by carbonate weathering. 78 CO 2 consumption rate by chemical weathering in the studied basin was 1.5 times of the world average rate. 78 Population density and agricultural practices contributed to major ions and CO 2 consumption. 78 CO 2 consumption by chemical weathering in the studied basin constituted a significant part of global carbon budget.
[20] Li Siliang, Liu Congqiang, Li Jun, et al.

Geochemistry of dissolved inorganic carbon and carbonate weathering in a small typical karstic catchment of Southwest China: Isotopic and chemical constraints

[J]. Chemical Geology, 2010, 277(3): 301-309.

DOI      URL      [本文引用: 1]      摘要

78 Soil CO 2 controls composition of dissolved inorganic carbon in karstic river. 78 Isotopic composition of DIC varies in response to partial pressure of CO 2. 78 Typical karstic catchment has a high weathering rate of carbonate rocks.
[21] Li Siliang, Calmels D, Han Guilin, et al.

Sulfuric acid as an agent of carbonate weathering constrained by 13CDIC: Examples from Southwest China

[J]. Earth and Planetary Science Letters, 2008, 270(3): 189-199.

DOI      URL      摘要

Rock weathering by carbonic acid is one of the important atmosphere CO2 sequestration. Actually, it depends on whether carbonic acid or other acids as weathering agents, which is important to understand the model of global carbon cycle. For example, sulf
[22] Liu Congqiang, Jiang Yingkui, Tao Faxiang, et al.

Chemical weathering of carbonate rocks by sulfuric acid and the carbon cycling in Southwest China

[J]. Geochimica, 2008, 37(4): 404-414.

[本文引用: 2]     

[刘丛强,蒋颖魁,陶发祥,.

西南喀斯特流域碳酸盐岩的硫酸侵蚀与碳循环

[J]. 地球化学, 2008, 37(4): 404-414.]

DOI      URL      [本文引用: 2]      摘要

流域化学侵蚀及其速率与流域生态和环境之间的关系是当前地表地球化学研究的重要前沿领域,其中碳酸盐岩的硫酸风化机制及其与区域碳循环的关系则是科学家们最为关注的科学问题。因此,近年通过研究西南喀斯特流域地表水地球化学对这一科学问题进行了研究,发现西南喀斯特地区河水一般含有较多的SO42-,从化学计量学、SO42-和δ34S和溶解无机碳(DIC)的δ13C分析发现,硫循环中形成的硫酸广泛参与了流域碳酸盐矿物的溶解和流域侵蚀:西南喀斯特流域碳酸盐岩的侵蚀速率为97 t/(km2·a),消耗CO2量为25 t/(km ·a)。对乌江流域河水硫酸盐离子的硫同位素研究结果认为:参与流域侵蚀的硫酸主要来自煤系地层硫化物和矿床硫化物的氧化及大气酸沉降,分别对河水SO42-的贡献为50%、27%和20.5%(其余2.5%的SO42-为硫酸盐蒸发岩的溶解);硫酸风化碳酸盐岩向大气净释放CO2的总通量为8.2 t/(km ·a),依此计算西南喀斯特区域向大气释放CO2的通量为4.4×10 g/a,相当于每年西南碳酸盐岩风化消耗CO2总通量的33%。将乌江流域的研究结果对我国大陆碳酸盐岩分布区域进行相应计算发现,硫酸风化碳酸盐矿物向大气释放的CO2总通量为28×10 g/a,相当于全球硅酸盐风化消耗CO2量的26% 。硫酸参与流域侵蚀改变了区域碳循环,人为过程可以通过释放酸沉降、矿业活动和土地利用等形式加速流域侵蚀和影响流域元素的生物地球化学循环。
[23] Pekey H, Karakas D, Bakoglu M.

Source apportionment of trace metals in surface waters of a polluted stream using multivariate statistical analyses

[J]. Marine Pollution Bulletin, 2004, 49(9/10): 809-818.

DOI      URL      PMID      [本文引用: 1]      摘要

Surface water samples were collected from ten previously selected sites of the polluted Dil Deresi stream, during two field surveys, December 2001 and April 2002. All samples were analyzed using ICP-AES, and the concentrations of trace metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Pb, Sn and Zn) were determined. The results were compared with national and international water quality guidelines, as well as literature values reported for similar rivers. Factor analysis (FA) and a factor analysis-multiple regression (FA-MR) model were used for source apportionment and estimation of contributions from identified sources to the concentration of each parameter. By a varimax rotated factor analysis, four source types were identified as the paint industry; sewage, crustal and road traffic runoff for trace metals, explaining about 83% of the total variance. FA-MR results showed that predicted concentrations were calculated with uncertainties lower than 15%.
[24] Guo H, Ding A J, So K L, et al.

Receptor modeling of source apportionment of Hong Kong aerosols and the implication of urban and regional contribution

[J]. Atmospheric Environment, 2009, 43(6): 1 159-1 169.

DOI      URL      摘要

Understanding the spatial–temporal variations of source apportionment of PM 2.5 is critical to the effective control of particulate pollution. In this study, two one-year studies of PM 2.5 composition were conducted at three contrasting sites in Hong Kong from November 2000 to October 2001, and from November 2004 to October 2005, respectively. A receptor model, principal component analysis (PCA) with absolute principal component scores (APCS) technique, was applied to the PM 2.5 data for the identification and quantification of pollution sources at the rural, urban and roadside sites. The receptor modeling results identified that the major sources of PM 2.5 in Hong Kong were vehicular emissions/road erosion, secondary sulfate, residual oil combustion, soil suspension and sea salt regardless of sampling sites and sampling periods. The secondary sulfate aerosols made the most significant contribution to the PM 2.5 composition at the rural (HT) (4402±023%, mean02±021 σ standard error) and urban (TW) (2802±022%) sites, followed by vehicular emission (2002±023% for HT and 2302±024% for TW) and residual oil combustion (1702±022% for HT and 1902±021% for TW). However, at the roadside site (MK), vehicular emissions especially diesel vehicle emissions were the major source of PM 2.5 composition (3302±021% for diesel vehicle plus 1802±022% for other vehicles), followed by secondary sulfate aerosols (2402±021%). We found that the contribution of residual oil combustion at both urban and rural sites was much higher than that at the roadside site (202±020.4%), perhaps due to the marine vessel activities of the container terminal near the urban site and close distance of pathway for the marine vessels to the rural site. The large contribution of secondary sulfate aerosols at all the three sites reflected the wide influence of regional pollution. With regard to the temporal trend, the contributions of vehicular emission and secondary sulfate to PM 2.5 showed higher autumn and winter values and lower summer levels at all the sites, particularly for the background site, suggesting that the seasonal variation of source apportionment in Hong Kong was mainly affected by the synoptic meteorological conditions and the long-range transport. Analysis of annual patterns indicated that the contribution of vehicular emission at the roadside was significantly reduced from 2000/01 to 2004/05 ( p 02<020.05, two-tail), especially the diesel vehicular emission ( p 02<020.001, two-tail). This is likely attributed to the implementation of the vehicular emission control programs with the tightening of diesel fuel contents and vehicular emission standards over these years by the Hong Kong government. In contrast, the contribution of secondary sulfate was remarkably increased from 2001 to 2005 ( p 02<020.001, two-tail), indicating a significant growth in regional sulfate pollution over the years.
[25] Simeonov V, Stratis J A, Samara C, et al.

Assessment of the surface water quality in Northern Greece

[J]. Water Research, 2003, 37(17): 4 119-4 124.

DOI      URL      PMID      摘要

The application of different multivariate statistical approaches for the interpretation of a large and complex data matrix obtained during a monitoring program of surface waters in Northern Greece is presented in this study. The dataset consists of analytical results from a 3-yr survey conducted in the major river systems (Aliakmon, Axios, Gallikos, Loudias and Strymon) as well as streams, tributaries and ditches. Twenty-seven parameters have been monitored on 25 key sampling sites on monthly basis (total of 22,350 observations). The dataset was treated using cluster analysis (CA), principal component analysis and multiple regression analysis on principal components. CA showed four different groups of similarity between the sampling sites reflecting the different physicochemical characteristics and pollution levels of the studied water systems. Six latent factors were identified as responsible for the data structure explaining 90% of the total variance of the dataset and are conditionally named organic, nutrient, physicochemical, weathering, soil-leaching and toxic-anthropogenic factors. A multivariate receptor model was also applied for source apportionment estimating the contribution of identified sources to the concentration of the physicochemical parameters. This study presents the necessity and usefulness of multivariate statistical assessment of large and complex databases in order to get better information about the quality of surface water, the design of sampling and analytical protocols and the effective pollution control/management of the surface waters.
[26] Thurston G D, Spengler J D.

A quantitative assessment of source contributions to inhalable particulate matter pollution in metropolitan Boston

[J]. Atmospheric Environment, 1985, 19(1): 9-25.

DOI      URL      摘要

In this paper, source apportionment techniques are employed to identify and quantify the major particle pollution source classes affecting a monitoring site in metropolitan Boston, MA. A Principal Component Analysis (PCA) of paniculate elemental data allows the estimation of mass contributions for five fine mass panicle source classes (soil, motor vehicle, coal related, oil and salt aerosols), and six coarse panicle source classes (soil, motor vehicle, refuse incineration, residual oil, salt and sulfate aerosols). Also derived are the elemental characteristics of those source aerosols and their contributions to the total recorded elemental concentrations (i.e. an elemental mass balance). These are estimated by applying a new approach to apportioning mass among various PCA source components: the calculation of Absolute Principal Component Scores, and the subsequent regression of daily mass and elemental concentrations on these scores. One advantage of the PCA source apportionment approach developed is that it allows the estimation of mass and source particle characteristics for an unconventional source category: transported (coal combustion related) aerosols. This particle class is estimated to represent a major portion of the aerosol mass, averaging roughly 40 per cent of the fine mass and 25 per cent of the inhalable particle mass at the Watertown, MA site. About 45 per cent of the fine particle sulfur is ascribed to this one component, with only 20 per cent assigned to pollution from local sources. The composition of the coal related aerosol at this site is found to be quite different from particles measured in the stacks of coal-fired power plants. Sulfates were estimated to comprise a much larger percentage of the ambient coal related aerosol than has been measured in stacks, while crustal element percentages were much reduced. This is thought to be due to primary panicle deposition and secondary aerosol accretion experienced during transport. Overall, the results indicate that the application of further emission controls to local point sources of particles would have less influence on fine aerosol and sulfate concentrations than would the control of more distant emissions causing aerosols transported into the Boston vicinity.
[27] Li J Y, Zhang J.

Effect of atmospheric precipitation on the dissolved loads of the Dongjiang River, China

[J]. Journal of Environmental Sciences, 2004, 16(3): 502-508.

DOI      URL      PMID      摘要

The atmospheric precipitation plays an important role in influencing the river chemistry of the Dongjiang River. The atmospheric contribution to river water is estimated by reference to Cl concentration called Clref. The Clref of 41.97 μmol/L represents the highest chloride concentration of the rainwater inputs to river water, thus sea salts are responsible for total Cl concentration of the Dongjiang River. According to the principal compositions of precipitation and river water, we propose two approaches-sea salt correction and precipitation correction in order to correct the contribution proportions of atmospheric precipitation on the solutes and to calculate chemical weathering rate. The results reflected that the atmospheric contribution ratios fluctuate from ~5% to ~20% of TDS(total dissolved solids) in the Dongjiang River. As compared with the other world watersheds, the lower dissolved ion contents and high runoff may result in the obvious influence of precipitation on river chemistry in the Dongjiang basin. The major elemental chemistry is mainly controlled by silicate weathering, with the anion HCO3- and cation Ca2+ and Na+ dominating the major compositions in this basin. The estimated chemical weathering rate of 15.78-23.48 t/(km2·a) is only 40%-60% of a global average in the Dongjiang basin. Certainly, the estimated results are still under correction gradually because the effect of human activities on the precipitation chemistry has never been quantified in detail.
[28] Li S Y, Zhang Q F.

Response of dissolved trace metals to land use/land cover and their source apportionment using a receptor model in a subtropic river, China

[J]. Journal of Hazardous Materials, 2011, 190(1/3): 205-213.

DOI      URL      PMID      [本文引用: 1]      摘要

Water samples were collected for determination of dissolved trace metals in 56 sampling sites throughout the upper Han River, China. Multivariate statistical analyses including correlation analysis, stepwise multiple linear regression models, and principal component and factor analysis (PCA/FA) were employed to examine the land use influences on trace metals, and a receptor model of factor analysis-multiple linear regression (FA-MLR) was used for source identification/apportionment of anthropogenic heavy metals in the surface water of the River. Our results revealed that land use was an important factor in water metals in the snow melt flow period and land use in the riparian zone was not a better predictor of metals than land use away from the river. Urbanization in a watershed and vegetation along river networks could better explain metals, and agriculture, regardless of its relative location, however slightly explained metal variables in the upper Han River. FA-MLR analysis identified five source types of metals, and mining, fossil fuel combustion, and vehicle exhaust were the dominant pollutions in the surface waters. The results demonstrated great impacts of human activities on metal concentrations in the subtropical river of China.
[29] Huang Qibo, Qin Xiaoqun, Liu Pengyu,et al.

The influence of allogenic water and sulfuric acid to karst carbon sink in karst subterranean river in Southern Hu’nan

[J]. Advances in Earth Science, 2017, 32(3): 307-318.

[本文引用: 1]     

[黄奇波,覃小群,刘朋雨,.

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

[J]. 地球科学进展, 2017, 32(3): 307-318.]

DOI      URL      [本文引用: 1]      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CO2对岩石风化碳汇的重要贡献,并评价了H2SO4参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SiO2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+,SiO2浓度有一定贡献;②4条地下河的[Ca2++Mg2+]/[HCO3-]当量比值为1.05 ~1.15,[Ca2+ +Mg2+][HCO3-+SO42-]的当量比值为0.99 ~ 1.08,Ca2+ +Mg2+相对于HCO;过量,过量的Ca2+ +Mg2+与SO42-相平衡,证实硫酸参与流域碳酸盐岩的溶蚀;③L01和L02地下河岩石风化消耗的CO2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CO2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%.
[30] Meybeck M.

Global chemical weathering of surficial rocks estimated from river dissolved loads

[J]. American Journal of Science, 1987, 287(5): 401-428.

DOI      URL      摘要

Abstract This article starts from the representative water analyses for major rock types commonly found on the continents. A theoretical world average is then set up on the basis of global outcrop proportions and compared to the observed composition. After discussion, this theoretical average is apportioned into the individual contributions from various minerals and rocks. As the water analyses are mostly derived from a previous study of unpolluted monolithologic French watersheds, this approach is called the Temperature Stream Model.
[31] Li Jingying.

A Study on the Chemieal Weathering,Mechanical Denudation Correlative with River Water and Sediment Geochemistry and CO2 Consumption Budget and Contolling Fators in the Major Drainage Basin of China[D].

Qingdao: Ocean University of China, 2003.

[本文引用: 6]     

[李晶莹.

中国主要流域盆地的风化剥蚀作用与大气CO2的消耗及其影响因子研究[D]

. 青岛:中国海洋大学, 2003.]

[本文引用: 6]     

[32] Liu Jiandong, Hu Hong, Zhang Longjun.

Progress of carbon sink by chemical weathering of watershed

[J]. Chinese Journal of Soil Science, 2007, 38(5): 998-1 002.

[本文引用: 1]     

[刘建栋,胡泓,张龙军.

流域化学风化作用的碳汇机制研究进展

[J]. 土壤通报, 2007, 38(5): 998-1 002.]

[本文引用: 1]     

[33] Li Jingying, Zhang Jing.

Chemical weathering processes and atmospheric CO2 consumption in the Yellow River drainage basin

[J]. Marine Geology & Quaternary Geology, 2003, 23(2): 43-49.

[本文引用: 2]     

[李晶莹,张经.

黄河流域化学风化作用与大气CO2的消耗

[J]. 海洋地质与第四纪地质, 2003, 23(2): 43-49.]

URL      [本文引用: 2]      摘要

通过对黄河水化学的相关分析和因子分析,得到大气CO2、碳酸 盐、蒸发盐、硅酸盐风化过程对黄河水溶解质的贡献率分别为:9.78%、37.3%、37.6%和7.54%,表明黄河流域碳酸盐和蒸发盐的溶解是最主要 的风化过程,对河水化学的总贡献率达到74.9%.黄河水中约90%的HCO3-来自碳酸盐风化过程,10%来自硅酸盐化学风化.由此对流域现代风化率和 大气CO2消耗量进行了估算,得到黄河流域化学风化率和CO2消耗率分别为33.6 t/km2*a和143.85×103 mol/km2*a,其中碳酸盐和硅酸盐风化过程消耗的CO2分别为117.70×103 和26.15×103 mol/km2,黄河流域每年消耗的大气CO2总量达到108×109 mol.与世界流域盆地年均消耗CO2量相比,虽然黄河流域的化学风化率属世界平均水平,但黄河流域风化作用的CO2消耗率却比世界平均值低约41%,这 是因为黄河流域是世界上蒸发盐含量最高的地区之一,流域蒸发盐、碳酸盐风化作用占主导地位,而硅酸盐风化作用很微弱.
[34] Xie Chenji, Gao Quanzhou, Tao Zhen, et al.

Chemical weathering and CO2 consumption in the Dongjiang River Basin

[J]. Acta Scientiae Circumstantiae, 2013, 33(8): 2 123-2 133.

[本文引用: 1]     

[解晨骥,高全洲,陶贞,.

东江流域化学风化对大气CO2的吸收

[J]. 环境科学学报, 2013, 33(8): 2 123-2 133.]

[本文引用: 1]     

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