洪家渡水库溶解二氧化碳分压的时空分布特征及其扩散通量  

Spatiotemporal characteristics and diffusion flux of partial pressure of dissolved carbon dioxide(pCO_2) in Hongjiadu reservoir

作　　者：喻元秀[1] 刘丛强[1] 汪福顺[2] 王宝利[1] 王仕禄[1] 刘芳[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室 [2]上海大学环境与化工学院,上海201800

出　　处：《生态学杂志》2008年第7期1193-1199,共7页Chinese Journal of Ecology

基　　金：国家重点基础发展研究计划项目(2006CB403205);国家自然科学基金资助项目(90610037、40571158和40603006)

摘　　要：为了了解水库温室气体的释放特征，于2006年4月、7月、10月和2007年1月对中国西南喀斯特地区新建的洪家渡水库入库水体、出库水体和水库坝前水体的CO2分压（pCO2）特征进行了分析。结果表明：入库河流pCO2为春季〈夏季〈秋季〈冬季，其中，六冲河全年平均值为488μatm，凹水河全年平均值为624μatm；水库库区表层水体pCO2冬季最高，春季最低，分别为925和279μatm，全年平均值为598μatm；在水体垂直剖面上，pCO2随水深的增加而增加；出库水体pCO2夏季最高，达8417μatm，春季最低，为382μatm，全年平均值为3260μatm。就全年平均而言，入库水体、水库库区表层水体以及出库水体pCO2均高于大气CO2分压（380μatm），其向大气中释放的CO2通量分别为3．93—6．29、4．87—7．79和64．29—102．86mmol·m^-2·d^-1。该水库总体上是大气CO2的源，天然河流水体经水库作用后CO2释放强度增加，导致水库泄水pCO2为天然河流的16倍、水库库区表层水体的13倍，其向大气中释放CO2量也相应增加。因此，水库泄水的CO2释放问题值得关注。In order to understand the characteristics of greenhouse gases emission from artificial reservoirs, the distribution characteristics of partial pressure of dissolved carbon dioxide （pCO2 ） in inflow waters, outflow waters, and the waters in Hongjiadu reservoir, a newly-buih reservoir located in Guizhou Province of Southwest China, were analyzed in April, July and October 2006 and January 2007. The results showed that the pCO2 value in inflow waters was spring 〈 summer 〈 autumn 〈 winter, and the annual average pCO2 in the inflow waters from Liuchong fiver and Washui river was 488 and 624 μatm, respectively. The pCO2 in reservoir epilimnion reached to the highest value （925 μatm） in winter and the lowest （279 μatm） in spring, with the annual average of 598 txatm. The pCO2 in water column increased with water depth. In the outflow wa- ters, pCO2 was the highest （8 417 txatm） in summer and the lowest in winter （382 μatm）, with the annual average value of 3 260μatm. The annual average pCO2 in inflow waters, reservoir epilimnion, and outflow waters was higher than that of air （380 μatm pCO2 ） , and the diffusion flux of CO2 at water-air interface was 3.93-6.29, 4.87-7.79 and 64.29-102. 86 mmol · m^-2 d ^- 1, respectively, showing that the reservoir should be a CO2 source of the atmosphere. Through the action of the reservoir, the diffusion flux of CO2 was enhanced, with the pCO2 in outflow waters being 16- and 13 folds of that in inflow waters and reservoir epilimnion, respectively. Accordingly, much attention should be paid on the CO2 emission from the outflow waters of the reservoir.

关 键 词：温室气体 CO2分压 水库 CO2扩散通量 

分 类 号：X832[环境科学与工程—环境工程]