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论文通过改进遥感蒸散模型的关键参数,结合遥感数据和气象观测数据,对2003—2008年江西千烟洲人工林生态系统蒸散及其组分进行模拟,并利用涡度相关技术获取的蒸散实测数据对模型模拟结果进行验证和评价。结果表明:①年均蒸散总量模拟值比实测值偏低2.4%,决定系数与均方根误差分别为0.83和0.61 mm.d-1。②土壤蒸发、林冠截留蒸发和植被蒸腾分别占总蒸散量的12%、23%和65%。其中,土壤蒸发季节及年际变化相对稳定;林冠截留蒸发季节变化明显且在不同年份差异较大;植被蒸腾季节变化明显,但年际变异较小。③1—3月植被光合作用较弱,植被蒸腾与蒸散比小于30%。随着植被蒸腾的增强,从4月开始植被蒸腾与蒸散比迅速增加,在生长旺季(7月底)可达到约90%。由于该模型所需数据在区域尺度较易获取,从而为开展区域尺度中亚热带人工林生态系统蒸散及其组分模拟提供方法支撑。
By improving the key parameters of remote sensing evapotranspiration model and combining the remote sensing data and meteorological observation data, the paper simulated the evapotranspiration and its components of plantation ecosystem in Qianyanzhou of Jiangxi Province during 2003-2008. The measured data of evapotranspiration The model simulation results are validated and evaluated. The results showed that: (1) The simulated annual total evapotranspiration was 2.4% lower than the measured value, and the determination coefficient and root mean square error were 0.83 and 0.61 mm.d-1, respectively. Soil evaporation, canopy interception evaporation and vegetation transpiration respectively accounted for 12%, 23% and 65% of the total evapotranspiration. Among them, the soil evaporation season and the interannual variation were relatively stable. The canopy interception evapotranspiration had a significant seasonal change and varied greatly in different years. The vegetation transpiration season changed obviously, but the interannual variability was small. ③ January-March vegetation photosynthesis is weak, vegetation transpiration and evapotranspiration less than 30%. With the increase of vegetation transpiration, the transpiration and evapotranspiration rate of vegetation increased rapidly from April, reaching about 90% during the peak growing season (the end of July). Because the data needed by the model are more accessible at the regional scale, it provides a methodological support for carrying out evapotranspiration and component simulation in subtropical plantation ecosystems at the regional scale.