摘要
地下水以其分布广泛,水量巨大,溶解无机碳(DIC)含量高而对全球碳循环具有重要的影响。然而,目前对地下水中的碳循环主要关注于其向地表水的排放,对整个地下水系统中碳的迁移转化研究鲜有报道。为探究地下水系统在全球碳收支中的作用,文章以红碱淖流域为例,利用质量守恒原理、水文地球化学模拟方法构建地下水系统碳平衡方程,分析地下水中碳的补排。结果表明,红碱淖流域地下水系统属于“碳汇”,年汇碳量为661.19~805.33 t。其中,碳酸盐岩的溶解(白云石)-沉淀(方解石)是影响地下水碳平衡的主要水化学作用;大气降水中的HCO-3和包气带CO_(2)是该区地下水中DIC的主要补给来源。根据计算,每年由水-岩相互作用进入地下水的碳量为451.05 t;通过降水入渗、侧向补给和农田灌溉补给地下水的碳量总计952.47~1 039.24 t;通过向湖泊排泄及地下水开采排放的碳量为684.96~742.36 t。
Groundwater has an important impact on the global carbon cycle because of its wide distribution, huge water volume and high DIC content. However, the carbon cycle in groundwater mainly focuses on its discharge to surface water, and there are few reports on the migration and transformation processes of carbon in the whole groundwater system. To explore the role of groundwater system in the global carbon budget, taking the Hongjiannao basin as an example, this study constructs the carbon balance equation of groundwater system by using the principle of mass conservation and hydrogeochemical simulation method to analyze the supplement and discharge of carbon in groundwater. The results show that the groundwater system in Hongjiannao basin belongs to “carbon sink” with an annual carbon sink of 661.19-805.33 t. Among them, the dissolution(dolomite)-precipitation(calcite) of carbonate rock is the main hydrochemical process affecting the carbon balance of groundwater;HCO-3in atmospheric precipitation and CO_(2)in vadose zone are the main recharge sources of DIC in groundwater in this area. According to the calculation result, the annual amount of carbon entering groundwater by water-rock interaction process is 451.05 t;The total carbon content of groundwater recharge through precipitation infiltration, lateral recharge and farmland irrigation is 952.47-1 039.24 t;The amount of carbon discharged through drainage to lakes and groundwater exploitation is 684.96-742.36 t.
作者
雷君豪
董少刚
张敏
高东辉
冯彦博
王锟
LEI Junhao;DONG Shaogang;ZHANG Min;GAO Donghui;FENG Yanbo;WANG Kun(School of Ecology and Environment,Inner Mongolia University,Hohhot 010021,China;Inner Mongolia Key Laboratory of River and Lake Ecology,Hohhot 010021,China;Inner Mongolia Academy of Ecological and Environmental Sciences,Hohhot 010021,China)
出处
《地球与环境》
CAS
CSCD
北大核心
2023年第1期47-55,共9页
Earth and Environment
基金
国家自然科学基金项目(41562020)。
关键词
水-岩相互作用
地下水
碳平衡
碳循环
二氧化碳
红碱淖
water-rock interaction
groundwater
carbon balance
carbon cycle
carbon dioxide
Hongjiannao basin
