新安江水库水体春季二氧化碳分压的分布规律研究

摘要

In order to evaluate the extent of CO2 emission from reservoir, this study investigated the partial pressure of CO2 (pCO2) in water of the Xin′anjiang reservoir and its river reach, in April 2010. pCO2 in surface water and in the water column were measured using a continuous measurement system (equilibrator-NDIR system). Results showed thatpCO2 in the surface water at incoming river reach of this reservoir was between 70~130 Pa; at the middle and central lake section, the surface water had pCO2 about 36~45 Pa and 60~70 Pa respectively. In the outlfow waters, pCO2 reached to 140 Pa, signiifcantly higher than that in central section. Along the water column, surface water had the lowest pCO2 of 68 Pa, and thepCO2 gradually increased downwardly. Below 10 m in depth,pCO2 had stable value around 105 Pa. Based on this study, it can be concluded that both the surface water and the outlfow waters of the XinAnJiang reservoir were the source to CO2, in the sampling season. However, when comparing with the incoming river reach, there is clear evidence showing that reservoir surface indeed has a role in mitigating the CO2 emission in this case.%为了了解水库温室气体的释放特征，于2010年4月利用喷淋—鼓泡式平衡器—非分散红外检测器系统对新安江水库表层水体二氧化碳分压p(CO2)进行了走航观测，及坝前水体剖面监测。走航结果表明库区河道p(CO2)区间为70~130 Pa，库区中段p(CO2)区间为36~45 Pa，库区坝前p(CO2)区间为60~70 Pa；水库出水p(CO2)为140 Pa，高于坝前表层水体；坝前剖面结果显示，在同一剖面上表面水体p(CO2)最低为68 Pa，此后p(CO2)随着深度增大持续增大，至水下10 m处开始保持稳定在105 Pa附近。该水库总体表现为大气CO2的源，但是通过对上游入库水体的比较发现该水库对温室气体释放缓解作用明显。