芦苇群落日蒸发蒸腾量变化规律及计算方法

The Change Trent in Daily Evapo-transpiration of Phragmites Communis and Its Computation Methods

了解芦苇湿地蒸发蒸腾量变化规律和影响因子并准确估算蒸发蒸腾量,对湿地水资源评估有十分重要的意义。根据2005年盘锦芦苇湿地监测站的小气候梯度系统和涡动相关系统的监测数据,结合芦苇生理生态特性的观测,分析芦苇群落的蒸发蒸腾量日变化规律及其主导影响因子,采用波文比-能量平衡法、梯度法对芦苇群落的日蒸发蒸腾过程进行模拟,并与涡动相关系统的实测数据进行比较。结果表明,芦苇群落蒸发蒸腾量日变化过程表现为早晚低、中午高的单峰曲线;从相关分析结果看,气象因素和芦苇生理生态特性对芦苇蒸发蒸腾的影响显著,其中辐射强度、相对湿度、温度、叶片光合速率和叶片气孔导度是芦苇群落蒸发蒸腾的主导影响因子;从计算蒸发蒸腾量的两种方法与涡动数据的比较结果看,梯度法更适合芦苇群落蒸发蒸腾量的模拟,可为芦苇湿地蒸发蒸腾的计算提供依据。

It is very important to understand the variation and leading factors of evapotranspiration in phragrnites communis wetland for estimating wetland water resource. Based on observations of the microclimate gradient, eddy covariance, and eco- physiological in the Panjin Wetland Ecosystem Research Station, Institute of Atmospheric Environment, China Meteorological Administration, the daily evapotranspiration variation and the leading factors were analyzed. The Bowen-Ratio energy balance method and gradient method were taken to simulate the daily evapotranspiration process of phragrnites communis, and the results was compared with the observation data of eddy covariance system. The results showed that the daily evapotranspiration variation process had the tendency of the single peak curve that was lower at morning and evening and higher at noon. According to the correlative analysis, meteorological factors and biological factors affected the evapotranspiration significantly. Especially, net radiation, relative humidity, air temperature, leaf photosynthetic rate and leaf conductance were the leading factors for the evapotranspiration of phragmites communis. In terms of the comparison of the results of two methods and the factual data of eddy variation, gradient method was better to simulate the evapotranspiration of phragrnites communis. This research can provide the support for the evapotranspiration calculation of phragrnites communis.