三江平原典型沼泽湿地蒸散发估测

Estimation of evapotranspiration from a typical marsh in Sanjiang Plain

2006年5-9月,利用涡度相关技术对三江平原典型沼泽湿地蒸散发进行了连续观测,在分析生长季内沼泽湿地蒸散发时间动态的基础上,采用Penman-Monteith(PM)和Priest-ley-Taylor(PT)模型分别模拟了沼泽湿地的日蒸散发,并利用实测值对两种模型的模拟精度进行了验证.结果表明:生长季内(5-9月),研究区沼泽湿地蒸散发具有明显的季节变化,月均日蒸散量在5月最低、7月最高;生长季内平均蒸散发为1.94mm.d-1,总蒸散量293mm.生长季前期和后期,与蒸散发实测值相比,PM模型的模拟值存在明显低估现象;PT模型模拟值与实测值在整个生长季内的一致性较好,且PT模型的形式简单、所需参数少,更适于沼泽湿地的蒸散发模拟.

Eddy covariance technique was adopted in measuring the evapotranspiration （ET） from a typical marsh in Sanjiang Plain in the growth season （May to September） of 2006. After analyzing the seasonal variation of the ET, the daily ET from the marsh was estimated by using Penman- Monteith （PM） and Priestley-Taylor （PT） models, and the estimated values were tested by the measured values. The results showed that the ET from the marsh had an obvious seasonal variation, with the lowest month-average daily ET in May and the highest one in July. The average daily ET in growth season was 1.94 mm·d^-1 , and the total ET was 293 mm. The daily ET estimated by PM model was significantly lower than the measured one during the early and late growth seasons. A good match was observed between PT-estimated values and measured values throughout the growth season. Considering its accuracy and simplicity, PT model was more suitable for the simulation of marsh ET.