重庆西部山区典型湖泊水-气界面CO2交换通量及其影响因素

为了解我国西南山区湖泊水体CO_2的释放/吸收特征,于2017年7月对重庆西部山区典型9个湖泊表层水体溶解性无机碳进行调查,并同步监测关键环境因子,运用薄边界层法和静态箱法对其水-气界面CO_2通量F(CO_2)]进行比较研究.结果表明,渝西山区湖泊夏季表层水p(CO_2)介于2.1~45.0 Pa之间,均值为(18.1±12.1) Pa;模型法和静态箱法计算的CO_2通量均值分别为(-8.0±2.9)、(-3.4±3.6)和(-7.1±22.3) mmol·(m2·d)-1,总体表现出大气CO_2汇的特征.水体p(CO_2)和F(CO_2)与关键环境因子的相关分析,表明表层水p(CO_2)和F(CO_2)与风速和ORP显著正相关,与pH显著负相关.

Water-Air Interface CO2 Exchange Flux of Typical Lakes in a Mountainous Area of the Western Chongqing and Their Influencing Factors

To examine the mountainous lake CO₂ evasion in Southwest China, partial pressures of carbon dioxidep(CO₂)] and the CO₂ exchange fluxF(CO₂)] via the water-air interface of nine mountainous lakes in Chongqing, China, have been studied in summer using the thin boundary layer model (TBL) and floating chambers. Key water quality parameters were concomitantly measured. The results indicate that the pCO₂ in the mountainous lakes in western Chongqing ranges from 2.1 to 45.0 Pa, with a mean value of (18.1±12.1) Pa. The mean CO₂ fluxes calculated by the TBL model and chamber method are (-8.0±2.9), (-3.4±3.6), and (-7.1±22.3) mmol·(m²·d)^-1, respectively. The p(CO₂) and F(CO₂) have positive correlations with the wind speed and ORP but negative correlations with the pH. Our study indicates that mountainous lakes are atmospheric sinks of CO₂ and the TBL model should be cautiously adopted.