CAJ | 학술논문

为揭示碳酸盐岩风化对河流流域化学风化过程及碳汇效应的影响,以流经我国亚热带地区的典型河流———西江为对象流域,在2011年4月~2012年3月对西江阳朔、昭平、梧州三个干流断面每月定期和暴雨期加密分析河水水样。研究结果表明：(1)三个断面都属于偏碱性水质,水化学类型为HCO3—Ca型,电导率沿西江干流逐渐升高,这主要是体现了流域内广泛分布的碳酸盐岩对河水水化学特征的控制作用。(2)在一个完整的水文年中,通过对三个干流断面逐月计算得出西江河口梧州断面碳通量总通量为51.03×108kgCO2/a,昭平段和阳朔段分别为1.55×108kgCO2/a和1.80×108kgCO2/a；碳通量强度分别为15606.13kgCO2/km2/a、10373.61kgCO2/km2/a、32223.08kgCO2/km2/a。(3)流量为岩溶碳通量的主控因子,降雨影响流量,进而影响碳汇效应的这种现象可能会受到人为作用的干扰。三个干流水体HCO3-浓度的变化趋势各有不同,这可能是因为HCO3-浓度与碳通量的关系比较复杂,涉及到不同的反应机理。三个断面的pH值和温度与碳通量没有明显的相关性,这可能是由于生物的“生物泵”作用主要是日变化为主,月尺度的pH和水温变化并不能真正反映pH和温度对碳通量的影响。
위게시탄산염암풍화대하류류역화학풍화과정급탄회효응적영향,이류경아국아열대지구적전형하류———서강위대상류역,재2011년4월~2012년3월대서강양삭、소평、오주삼개간류단면매월정기화폭우기가밀분석하수수양。연구결과표명：(1)삼개단면도속우편감성수질,수화학류형위HCO3—Ca형,전도솔연서강간류축점승고,저주요시체현료류역내엄범분포적탄산염암대하수수화학특정적공제작용。(2)재일개완정적수문년중,통과대삼개간류단면축월계산득출서강하구오주단면탄통량총통량위51.03×108kgCO2/a,소평단화양삭단분별위1.55×108kgCO2/a화1.80×108kgCO2/a；탄통량강도분별위15606.13kgCO2/km2/a、10373.61kgCO2/km2/a、32223.08kgCO2/km2/a。(3)류량위암용탄통량적주공인자,강우영향류량,진이영향탄회효응적저충현상가능회수도인위작용적간우。삼개간류수체HCO3-농도적변화추세각유불동,저가능시인위HCO3-농도여탄통량적관계비교복잡,섭급도불동적반응궤리。삼개단면적pH치화온도여탄통량몰유명현적상관성,저가능시유우생물적“생물빙”작용주요시일변화위주,월척도적pH화수온변화병불능진정반영pH화온도대탄통량적영향。
Abstact∶ To reveal the effects of carbonate weathering on chemical weathering processes and its carbon sink effect in river catch-ment, this paper took the Xijiang River in Guangxi as the research object, which is a typical river that flows through subtropical areas in China. The river water samples were collected from three mainstream sections: Yasngshuo, Zhaoping and Wuzhou, which were analyzed regular monthly and intensive observation during heavy rainfall period from April 2011 to March 2012. The research shows the results as follows: (1) The water of the three mainstream sections is alkali waste water and its hydrochemistry type be-longs to HCO3-Ca. EC (electric conductivity) increases gradually along the mainstream, this phenomenon primarily embodies the control effect to chemical characteristics by carbonate rock that is widespread in river catchment; (2) In a whole hydrological year, the total flux of carbon at three mainstream sections were calculated month by month, and 5.10 ×1012kgCO2/a at the Wuzhou sec-tion, 1.55 ×1012kgCO2/a and 1.80 ×1012kgCO2/a at the Zhaoping section and Yangshuo section respectively. The intensity of carbon flux is 15 606.13kgCO2/km2/a, 10 373.61kgCO2/km2/a and 32 223.08 kgCO2/km2/a respectively; (3) The flow is the primary factor of karst carbon flux, the phenomenon that rainfall influences flow, further influence the effect of carbon sink, it may be affected by human activity. The change trend of HCO3- concentrations is different in the water at the three mainstream sections, the possible reason is that the relationship between the HCO 3- concentrations and carbon flux is complex, and it relates various reaction mecha-nisms. The carbon flux has no obvious correlation with pH value and temperature, it may be caused by the effects that the biolog-ical pump is mainly diurnal variation, pH value and hydrological changes can not truly reflect the influence on the carbon sink by pH value and temperature in monthly scale.