宜昌求索溪冬季温室气体通量昼夜变化特征

Diel variation of greenhouse gas flux from Qiusuo River of Yichang in winter

为探索小型水域温室气体的排放规律,采用温室气体快速分析仪-密闭式静态通量箱法对湖北宜昌市三峡大学求索溪冬季水-气界面温室气体通量(CH4和CO2)进行了24 h连续观测。观测结果显示,CH4和CO2的变化呈正相关,CH4和CO2全天均处于释放状态;CO2通量与气压、水温呈正相关,与气温、p H值、溶解氧、叶绿素a呈负相关;CH4仅与气压呈正相关而与其他环境因子均呈现负相关;CH4和CO2在10:00和21:00左右同时接近全天的平均值,该时段可作为单次采样时间参考。

To investigate the emission law of greenhouse gas in small water body,by using LGR-floating static flux chamber method,a 24-hour field continuous observation was carried out to quantify the CH4 and CO2fluxes across the water-air interface of Qiusuo River in China Three Gorges University at Yichang.The observed results showed that CH4 and CO2are positively correlated,both of which emitted all day.Moreover,the correlation analysis indicated that CO2 flux had a significant positive correlation with water temperature and air-pressure,but a negative correlation with temperature,p H,dissolved oxygen and chlorophyll a; CH4 flux had a positive correlation with air-pressure and negative correlation with other factors; CH4 and CO2fluxes at10： 00 and 21： 00 are close to the average values of a day,so this period can be referred as sampling time for a single measurement.