三江平原典型沼泽湿地能量平衡和蒸散发研究

Studies of the energy balance and evapotranspiration over the typical marsh wetland in Sanjiang plain

基于涡度相关技术对三江平原典型沼泽湿地的水热通量进行了连续观测，研究沼泽湿地能量平衡和蒸散发的季节变化，确定观测期内沼泽湿地总蒸散量，并通过逐步回归方程估算沼泽湿地水面蒸发和植被蒸腾。结果表明，沼泽湿地的能量平衡具有明显的季节变化特征，总体看来，潜热通量是湿地的主要能量支出项，占净辐射的45.5％，感热通量和存储热通量分别占净辐射的27.9％和26.7％。2006年5～10月份沼泽湿地总蒸散量为310.6mm，月均日蒸散量最高值出现在7月。观测期内沼泽湿地水面蒸发量约为221mm，占总蒸散量的71％左右，植被蒸腾量则约占总蒸散量的29％，湿地蒸散发以水面蒸发为主。

During the period from May to October 2006, the continuous eddy covariance measurements is used to investigate the seasonal variation of energy balance and evapotranspiration and to determine the total evapotranspiration over the typical marsh wetland in Sanjiang plain. According to the regression analysis, the total evaporation and transpiration are estimated. The results show that there is obvious seasonal variation of the energy balance of marsh wetland. Overall, the latent heat flux dissipated 45.5 % of the net radiant energy, sensible heat flux 27.9 % and the storage heat flux 26.7 %. The total evapotran- spiration from May to October is 310.6 ram, and the highest month-average daily evapotranspiration appears in July. The total evaporation which accounts for about 71% of total evapotranspiration is about 221 nun, and the total transpiration accounts for 29 %. Therefore, the evaporation is the main contributor to the evapotranspiration over marsh.