太湖地区湖水与河水中溶解N2O及其排放

水体是N₂O排放的重要来源.2000-09～2001-09,每月2次采样(重复3次)连续监测太湖地区太湖和大运河水体N₂O排放通量和水中溶解的N₂O浓度,还同时监测不同深度水样中的N₂O浓度.结果表明,太湖N₂O-N的年均排放通量为3.53 μg/(m²·h),而大运河已高达122.5,μg/(m²·h).太湖湖水中溶解N₂O-N浓度为0.36μg/L,大运河河水中浓度高达11.31μg/L,浅水型水体是N2O排放的源.结果还表明,不同深度水中N2O浓度差异不明显,而时间差异显著.水面N2O的排放通量和水中溶解的N2O浓度呈显著正相关关系,二者又都与水温呈显著正相关. .

Dissolved N2O Concentrations and N2O Emissions from Aquatic Systems of Lake and River in Taihu Lake Region

Aquatic systems are an important source of N2O emissions. N2O concentrations dissolved in lake and river water in Taihu Lake region and N2O fluxes from these waterbodies were monitored twice a month in three replicate from Sept. 26, 2000 to Sept. 26, 2001. At the same time, both top and bottom water were analyzed for N2O concentrations four times in a consecutive year. Results demonstrated that rather high N2O-N concentrations of 11.31 micrograms/L were dissolved in river water and resulted in high N2O-N fluxes of 122.5 micrograms/(m2.h) from river water surfaces while low N2O-N concentration of 0.36 microgram/L and N2O-N flux of 3.53 micrograms/(m2.h) was found in lake water. No obvious difference was found in dissolved N2O concentration between top water and bottom water. Results also indicated that there existed significantly positive relationship between dissolved N2O concentration and N2O flux and water temperature. The results indicate that the aquatic systems are an important source of N2O.