利用声学调查法和沉积柱理化参数评估河道型水库碳埋藏通量  

Using seismic surveys and physicochemical data of sediment cores to assess the carbon burial flux of the channel-type reservoir

作　　者：秦勇 付文军 包宇飞 顾菲 厉励 曹珍 李小影 Qin Yong;Fu Wenjun;Bao Yufei;Gu Fei;Li Li;Cao Zhen;Li Xiaoying(Xinyang Agriculture and Forestry University,Xinyang 464000,P.R.China;Department of Water Ecology and Environment,China Institute of Water Resources and Hydropower Research,Beijing 100038,P.R.China;Xinyang Research Center of Engineering and Technology on Carbon Neutrality of the Riparian Zone in Huaihe River Basin,Xinyang 464000,P.R.China;Yangtze River Ecological Environment Engineering Research Center,China Three Gorges Corporation,Beijing 100028,P.R.China;School of Environmental and Chemical Engineering,Shanghai University,Shanghai 200444,P.R.China)

机构地区：[1]信阳农林学院,信阳464000 [2]中国水利水电科学研究院水生态环境研究所,北京100038 [3]信阳市淮河流域消落带碳中和工程技术研究中心,信阳464000 [4]中国长江三峡集团有限公司长江生态环境工程研究中心,北京100028 [5]上海大学环境与化学工程学院,上海200444

出　　处：《湖泊科学》2024年第6期1820-1833,共14页Journal of Lake Sciences

基　　金：河南省自然科学基金项目(222300420271);国家自然科学基金项目(52309107,U2340222);中国长江三峡集团有限公司项目(201903144);信阳农林学院青年基金项目(QN2022028)联合资助。

摘　　要：河道型水库对有机碳具有重要的拦截作用,影响内陆水体碳循环。然而,河道型水库水体滞留时间较短,其碳埋藏效应容易被忽视。受野外观测方法的限制,准确地评估河道型水库碳汇潜力面临挑战。声学调查法能够全面反映水库沉积物淤积分布,是一种快速、经济和准确的水库碳埋藏评估方法。本研究采用声学调查法、沉积柱理化参数和碳同位素技术,对乌江流域河道型水库(思林水库)有机碳埋藏开展了调研。结果表明,思林水库沉积物厚度变化范围为0~3.53 m,不规则的水下地形导致沉积物淤积分布具有高度的空间异质性。思林水库沉积物有机碳含量、C/N摩尔比和δ13 C值变化范围分别为1.03%~3.40%、4.62~9.14和-28.5‰~-23.8‰,平均值分别为1.93%、7.24和-26.6‰,显示沉积物有机碳主要来源于水生浮游植物。思林水库内源有机碳对沉积物总有机碳的贡献比例范围为21.2%~85.1%,平均值为60.1%。沉积物内源有机质含量与营养盐氮磷浓度呈显著正相关,表明营养盐氮磷的输入促进了内源有机质的生成。思林水库有机碳埋藏速率变化范围为0~12133.4 g/(m^(2)·a),平均值为1429.8 g/(m^(2)·a),有机碳埋藏通量为2.16×10^(10)g/a,相当于全球水库有机碳埋藏通量的0.36‰,表明河道型水库碳汇潜力不容忽视。思林水库内源有机碳通量为1.30×10^(10)g/a,相当于水气界面CO 2释放通量的0.32倍。本研究水库和其他研究的水库有机碳埋藏速率与水体滞留时间呈对数函数关系,该经验函数将有助于估算全球水库有机碳埋藏速率。The river-type reservoirs play an important role in intercepting organic carbon(OC),which affects the carbon cycle in inland waters.However,the carbon burial effect of the channel-type reservoir is easily ignored because of its short hydraulic retention time.Limited by the methods of field observations,it remains a challenge to accurately evaluate the carbon sink potential of channel-type reservoirs.The seismic approach can comprehensively reflect the distribution of sediment deposition in reservoirs,which is a fast,economical,and accurate evaluation method of OC burial in reservoirs.In this study,we investigated the organic carbon burial in the channel-type reservoir(Silin Reservoir)in the Wujiang River using seismic surveys,physicochemical data of sediment cores and carbon isotope technique.The results indicated that the sediment thickness of Silin Reservoir varied from 0 to 3.53 m.The irregular underwater topography resulted in a high spatial heterogeneity of the sediment deposition distribution.The OC content,C/N molar ratio andδ13 C value of sediments in Silin Reservoir ranged from 1.03%to 3.40%,from 4.62 to 9.14,and from-28.5‰to-23.8‰,with mean values of 1.93%,7.24 and-26.6‰,respectively.The C/N molar ratio andδ13 C value of sediments suggested that sedimentary OC were mainly derived from aquatic phytoplankton.δ13 C values coupled with a two-end-member mixing model showed that the contribution of autochthonous OC to total organic carbon in Silin Reservoir varied from^(2)1.2%to 85.1%,with a mean value of 60.1%.The significantly positive relationship between autochthonous OC and total nitrogen(TN)and between autochthonous OC and total phosphorus(TP)suggested that the input of nutrients promoted the generation of autochthonous OC in the reservoir.The OC burial rate(OCBR)of the Silin Reservoir ranged from 0 to 12133.4 g/(m^(2)·a),with an average of 1429.8 g/(m^(2)·a).The OC burial flux in Silin Reservoir was 2.16×10^(10)g/a,which accounted for 0.36‰of OC burial flux of global reservoirs,indicating

关 键 词：河道型水库 思林水库 有机碳埋藏 声学调查法 柱状沉积物 碳同位素 水体滞留时间 

分 类 号：X143[环境科学与工程—环境科学]